Climate of Odisha

Climate refers to the long-term average weather conditions in a particular region or on Earth as a whole. It encompasses various elements such as temperature, precipitation, humidity, wind patterns, and atmospheric pressure. Climate is determined by complex interactions between the atmosphere, oceans, land surfaces, and other factors like solar radiation and greenhouse gases.

Climate is typically described in terms of patterns and trends over extended periods, often spanning several decades or centuries. It is influenced by both natural factors, such as volcanic activity, solar radiation, and variations in Earth’s orbit, as well as human activities, including the burning of fossil fuels, deforestation, and industrial processes. The latter has become a significant driver of climate change in recent decades.

Odisha, located on the east coast of India facing the Bay of Bengal, has a tropical monsoon climate. The state experiences monsoonal rainfall from mid-June to mid-October, similar to other parts of India. The climate in Odisha is greatly influenced by its proximity to the sea, resulting in high temperatures during April and May. The Eastern Ghats region, on the other hand, experiences extremely cold weather.

Factors Influencing the Climate of Odisha

Several factors influence the climate of Odisha, a state located on the eastern coast of India. These factors include:

Latitude and Longitude: Odisha is situated between approximately 17° 49′ N and 22° 34′ N latitudes and 81° 27′ E and 87° 29′ E longitudes. Its proximity to the equator influences its climate, making it predominantly tropical.
Monsoon Winds: The southwest monsoon and the northeast monsoon greatly impact Odisha’s climate. The southwest monsoon, which occurs from June to September, brings heavy rainfall to the state. The northeast monsoon, from October to December, contributes to rainfall in the northern parts of Odisha.
Topography: Odisha has a diverse topography, including coastal plains, hills, and plateaus. The coastal plains are influenced by the sea breeze and experience a maritime climate. The hilly and plateau regions have a milder climate due to their higher elevations.
Ocean Currents: The presence of the Bay of Bengal on Odisha’s eastern coast affects its climate. The warm waters of the Bay of Bengal contribute to high humidity and help fuel the monsoon system, leading to abundant rainfall.
Rainfall: Odisha receives a significant amount of rainfall, primarily during the monsoon seasons. The state experiences an average annual rainfall of around 1,500–1,800 millimeters.
Cyclones: Odisha is prone to tropical cyclones that originate in the Bay of Bengal. These cyclones bring heavy rainfall, strong winds, and storm surges, impacting the climate and causing occasional severe weather events.
Forest Cover: Odisha has substantial forest cover, which plays a role in local climate regulation. Forests contribute to moisture retention, temperature moderation, and influence local wind patterns.
El Niño and La Niña: The El Niño-Southern Oscillation (ENSO) phenomenon, characterized by warm (El Niño) or cold (La Niña) oceanic conditions in the Pacific Ocean, can impact Odisha’s climate. El Niño events often lead to drier conditions, while La Niña events can bring increased rainfall.

The year in Odisha is divided into three major seasons:

Summer (March–June)
Monsoon (July–September)
Winter (October–February)

The western districts of Sundergarh, Sambalpur, Bargarh, Bolangir, Kalahandi, and Mayurbhanj have warm temperatures throughout the year, with maximum temperatures ranging between 40–46°C during summer and cool temperatures during winter.

The coastal districts have an equable climate with high humidity and stickiness. The summer maximum temperature in these areas ranges between 35–44°C, while the low temperatures usually range between 12–14°C.

Some areas in Koraput and Phulbani experience more severe winters, with minimum temperatures dropping to 3–4°C. Daringbadi, known as the “Kashmir of Odisha,” is the only place in the state that receives snow, with temperatures reaching zero degrees during winter.

Precipitation is the dominant element of climate in Odisha, with an average rainfall of about 150 cm. The southwest monsoon from July to September brings the majority of the rainfall, with July being the wettest month. The state also experiences some rainfall from the retreating monsoon in October and November. January and February are relatively dry months.

Köppen’s climatic classification categorizes most parts of Odisha under the AW category, representing a tropical Savanna type of climate. Odisha is not directly influenced by the southwest monsoon branch from the Bay of Bengal like the west coast of India. However, annual cyclones from the Bay of Bengal do bring copious rainfall, with two seasonal peaks in July–August and October–November.

The Kendujhar and Baripada highlands receive over 175 cm of rainfall annually. The isohyetal lines of 150 cm pass over Sambalpur, Redhakhol, Talcher, Barchana, Bhadrak, and Balasore. The Mahanadi Delta, highlands of Phulbani and Tarapara, and most of the Mahanadi valley, Tel basin, and Rushikulya basin receive lower rainfall compared to northern and southwestern Odisha.

During winter, except for the northern part, the rest of Odisha remains dry as the retreating northeastern monsoon winds move over the landmass before reaching the state.

The rainfall during the southwest monsoon is highest in western Odisha, exceeding 80 percent of the total annual rainfall. The Inland Rolling Uplands also receive a significant percentage of annual rainfall during this season. The percentage of rainfall gradually declines to 60 percent in the Ganjam plains, while the coastal plains, as a whole, receive 70 percent of the total annual rainfall during the southwest monsoon.

This indicates that cultivation in the western regions of the Eastern Ghats is challenging during the rest of the year due to the lack of rain, emphasizing the need for irrigation to support double cropping.

Koppen’s Climatic Classification for Odisha

According to Koppen’s climatic classification, Odisha falls into multiple climate types due to its diverse geography and varied weather patterns. The major climate types observed in Odisha are as follows:

Tropical Savanna Climate (Aw): The majority of Odisha is classified as having a tropical savanna climate. This climate is characterized by distinct wet and dry seasons. The region experiences a hot and humid summer with abundant rainfall during the monsoon season, followed by a cooler and drier winter. The average temperature in this climate type ranges between 20–30°C, and the annual rainfall is around 150 cm.
Tropical Monsoon Climate (Am): Some parts of Odisha, especially along the coastal areas, have a tropical monsoon climate. This climate type is similar to the tropical savanna climate but with a shorter dry season. These regions experience high humidity, heavy rainfall, and strong monsoon winds during the summer months, with average temperatures ranging from 25–35°C.
Subtropical Highland Climate (Cwa): The Eastern Ghats region of Odisha, including areas like Phulbani, experiences a subtropical highland climate. This climate type is characterized by mild to warm summers and cool winters. The average temperature in summer ranges from 25–30°C, while in winter, it can drop to around 10–15°C. The region receives moderate to heavy rainfall throughout the year, with the highest precipitation occurring during the monsoon season.
Subtropical Steppe Climate (BSh): Some parts of western Odisha, particularly in the rain shadow area of the Eastern Ghats, exhibit a subtropical steppe climate. This climate is characterized by hot summers, mild winters, and relatively low rainfall. The average temperature during summer ranges from 35–40°C, and in winter, it varies between 15–25°C. The annual rainfall in these areas is comparatively lower, usually less than 75 cm.

Note: It is important to note that while these climate types provide a general classification, local variations in topography and proximity to the coast can result in microclimates and localized weather patterns within the state of Odisha.

Climatic Regions of Odisha Based on Rainfall

Based on rainfall patterns, Odisha can be divided into four distinct climatic regions. These regions are primarily determined by the amount and distribution of rainfall throughout the year. The four climatic regions of Odisha based on rainfall are as follows:

1. High Rainfall Region

This region includes the coastal areas of Odisha, particularly the eastern coastal plains and the Mahanadi Delta region. These areas receive the highest amount of rainfall in the state. The average annual rainfall ranges from 150 cm to 200 cm or more. The rainfall is predominantly influenced by the southwest monsoon and cyclonic activities from the Bay of Bengal. The wettest months are usually July and August, when the region experiences heavy downpours and occasional flooding.

2. Moderate Rainfall Region

The moderate rainfall region covers the inland areas of Odisha, including parts of the central and northern districts. The average annual rainfall in these areas ranges from 100 cm to 150 cm. These regions receive a significant amount of rainfall during the monsoon season, but the intensity is relatively lower compared to the coastal areas. The months of July to September are the wettest period, while the winter months are relatively dry.

3. Low Rainfall Region

The low rainfall region includes the western districts of Odisha, especially those situated in the rain shadow of the Eastern Ghats. These areas receive comparatively lower rainfall, with an average annual precipitation of less than 100 cm. The rainfall is highly influenced by the southwest monsoon winds, but due to the barrier effect of the Eastern Ghats, these regions receive less rainfall. The summer months are relatively dry, while the monsoon season brings some rainfall.

4. Drought-Prone Region

The westernmost parts of Odisha, such as parts of the Kalahandi, Balangir, and Koraput districts, fall under the drought-prone region. These areas experience significantly lower rainfall compared to other regions in the state. The average annual rainfall is less than 75 cm, and these regions are prone to water scarcity and drought conditions. The monsoon rainfall is often inadequate, and the region heavily depends on alternative sources of water and irrigation for agricultural activities.

Seasons in Odisha

Odisha experiences three main seasons: summer, monsoon, and winter. Here’s a description of each season with the latest available data:

1. Summer (March–June)

Summer in Odisha is characterized by scorching heat and high temperatures. The summer season typically begins in March and extends until June. During this period, temperatures can soar, particularly in the western districts. Maximum temperatures often range between 40–46°C in places like Sundergarh, Sambalpur, Bargarh, Bolangir, Kalahandi, and Mayurbhanj. The coastal districts also experience high temperatures, with maximums ranging from 35–44°C.

The summer months can be uncomfortable due to the heat and humidity. It is worth noting that the temperatures mentioned are approximate values and can vary from year to year.

2. Monsoon (July–September)

The monsoon season in Odisha starts around mid-June and lasts until mid-October. The state receives a significant amount of rainfall during this period, mainly from the southwest monsoon. The month of July is usually the wettest, with heavy downpours and the possibility of flooding in major rivers.

The monsoon rainfall in Odisha is influenced by low-pressure systems and cyclones developing over the northern Bay of Bengal. The eastern coastal areas, including the Mahanadi Delta region, receive a higher amount of rainfall compared to other parts of the state. The average annual rainfall in Odisha is around 150 cm, but it can vary across different regions.

3. Winter (October–February)

The winter season in Odisha lasts from October to February. Winters in the state are relatively mild, although some areas may experience colder temperatures, especially in the higher elevations of the Eastern Ghats.

The coastal districts have a pleasant and moderate winter climate. Minimum temperatures in the winter months usually range between 12–14°C in the coastal areas, while some colder regions like Koraput and Phulbani can experience minimum temperatures as low as 3–4°C. The winters in Odisha are generally not severe except for certain pockets.

Summer in Odisha

The summer season in Odisha typically spans from March to June. During this period, the state experiences hot and dry weather conditions, with temperatures ranging from warm to very hot. Here is some information about the summer season in Odisha:

1. Temperature

In general, the temperatures during summer in Odisha can range from 30°C (86°F) to 45°C (113°F) or even higher in some areas. The coastal regions tend to have relatively milder temperatures due to the influence of sea breezes, while the interior and western parts of the state experience higher temperatures.

2. Heatwaves

Odisha, like other parts of India, can occasionally experience heatwaves during the summer season. Heatwaves are characterized by prolonged periods of excessively high temperatures, often exceeding 40°C (104°F), and can last for several days or weeks. Heatwaves can have adverse effects on human health, agriculture, and the environment.

3. Dry Weather

Summer in Odisha is associated with dry weather conditions. The state experiences minimal rainfall during this season, with the onset of the southwest monsoon typically occurring in June, bringing relief from the heat and initiating the rainy season.

4. Agricultural Activities

The summer season is critical for agriculture in Odisha. Farmers engage in activities such as sowing summer crops like rice, maize, pulses, and vegetables. Adequate irrigation and water management are essential during this period to support crop growth and prevent water stress.

5. Festivals and Cultural Significance

The summer season also holds cultural and religious significance in Odisha. Festivals like Raja Parba, a celebration of womanhood and fertility, and Akshaya Tritiya, a festival associated with agricultural prosperity and wealth, are observed during this time.

6. Tourism

Despite the hot weather, summer is a popular time for tourism in Odisha. The state boasts numerous scenic beaches, temples, and historical sites that attract tourists from within and outside the state. Coastal areas such as Puri, Konark, and Gopalpur-on-Sea are particularly popular tourist destinations during the summer season.

Note: It is important to note that specific weather conditions, temperatures, and the duration of the summer season can vary from year to year. For the most accurate and up-to-date information, it is recommended to refer to local weather forecasts and meteorological agencies like the India Meteorological Department (IMD) or regional weather offices in Odisha.

Monsoon in Odisha

The mechanism of the monsoon in Odisha is primarily influenced by the Southwest Monsoon, which is a seasonal wind system that brings rainfall to the Indian subcontinent. Here’s a general explanation of the monsoon mechanism in Odisha:

1. Southwest Monsoon

The Southwest Monsoon is a result of the differential heating of landmasses and oceans. During summer, the landmass in the Indian subcontinent heats up more rapidly than the surrounding oceans. As a result, a low-pressure system is formed over the land, attracting moist winds from the Indian Ocean.

2. Onset of Monsoon

The onset of the monsoon in Odisha typically occurs around the first week of June. Prior to the monsoon’s arrival, the state experiences high temperatures and pre-monsoon showers. As the monsoon advances, the southwest winds carrying moisture and rain clouds move towards the region.

3. Arrival of Monsoon

The monsoon reaches Odisha through two primary pathways:

Arabian Sea Branch: The monsoon winds enter Odisha through the Arabian Sea branch, which brings moisture from the Arabian Sea and travels along the western coastline of India. These winds carry ample moisture content and contribute to significant rainfall in the coastal regions of Odisha.
Bay of Bengal Branch: The Bay of Bengal branch of the monsoon is another important pathway for the monsoon to reach Odisha. Moisture-laden winds originating from the Bay of Bengal move towards Odisha, bringing rainfall to the eastern and northeastern parts of the state.

4. Rainfall Distribution

Once the monsoon reaches Odisha, it leads to widespread rainfall across the state. The coastal areas of Odisha generally receive higher rainfall compared to the inland regions. Places like Puri, Cuttack, and Bhubaneswar often receive substantial rainfall during the monsoon season.

5. Monsoon Withdrawal

The withdrawal of the monsoon from Odisha typically occurs around October. During this period, the monsoon retreats from the region, and the weather gradually transitions to the post-monsoon season.

Note: It is important to note that the monsoon in Odisha can be influenced by various factors, such as the El Niño–Southern Oscillation (ENSO) phenomenon, Indian Ocean Dipole (IOD) events, and local topography. These factors can affect the timing, intensity, and distribution of rainfall during the monsoon season in Odisha.

Onset and Withdrawal of the Monsoon in Odisha

The onset and withdrawal of the monsoon in Odisha are significant events that mark the beginning and end of the monsoon season in the state. These events play a crucial role in agriculture, water resources, and overall socio-economic activities. Here is a detailed analysis of the onset and withdrawal of the monsoon in Odisha:

Onset of Monsoon

The onset of the monsoon in Odisha generally occurs around the first week of June. However, the actual onset date may vary from year to year. The arrival of the monsoon is determined by various meteorological factors and weather patterns. The Southwest Monsoon, originating over the Arabian Sea, advances towards the east and reaches the Indian subcontinent, including Odisha.

The coastal regions of Odisha usually experience an earlier onset compared to the inland areas. Coastal districts such as Puri, Jagatsinghpur, and Kendrapara are among the first to receive monsoon rains. The onset of the monsoon is characterized by an increase in cloud cover, a decrease in temperature, and the occurrence of pre-monsoon showers or thunderstorms.

The India Meteorological Department (IMD) closely monitors and declares the official onset of the monsoon in different regions of the country, including Odisha. The IMD uses various parameters, including wind patterns, rainfall observations, and atmospheric conditions, to determine the onset dates and issue forecasts.

Withdrawal of Monsoon

The withdrawal of the monsoon from Odisha typically takes place around September. Similar to the onset, the withdrawal date may vary from year to year. The retreat of the monsoon is influenced by factors such as changes in wind patterns, atmospheric conditions, and the movement of weather systems.

The withdrawal of the monsoon from Odisha generally starts in the northwest region of the country and gradually progresses towards the east and southeast. The withdrawal process is characterized by a decrease in rainfall activity, an increase in temperatures, and changes in wind direction.

The IMD also monitors and announces the official withdrawal of the monsoon from different regions, including Odisha. The withdrawal is determined based on established criteria, including the reduction in rainfall, the establishment of anticyclonic circulation, and the overall retreat of the monsoon weather patterns.

Impact on Agriculture and Water Resources

The onset and withdrawal of the monsoon are critical for agricultural planning and water resource management in Odisha. The timely arrival of the monsoon ensures the availability of water for irrigation and supports the sowing and growth of crops. Adequate monsoon rainfall is vital for crop yields and overall agricultural productivity in the state.

Similarly, the withdrawal of the monsoon marks the transition to a drier period. Farmers need to complete harvesting and post-harvest activities before the withdrawal to avoid losses. Water storage and management become crucial during this time to ensure a continuous water supply for various uses, including irrigation, drinking water, and hydroelectric power generation.

El Niño and Its Effect on the Monsoon in Odisha

El Niño is a climate phenomenon that occurs irregularly in the tropical Pacific Ocean. It is characterized by unusually warm ocean temperatures in the eastern equatorial Pacific. El Niño can have significant effects on global weather patterns, including the monsoon season in various regions, including Odisha, a state in eastern India.

The monsoon in Odisha is a vital weather system that brings much-needed rainfall to the region. It typically occurs from June to September and is crucial for agriculture and water resources in the state. However, during El Niño years, the monsoon patterns can be affected, leading to variations from normal rainfall patterns.

El Niño tends to weaken the monsoon over the Indian subcontinent, including Odisha. The warm oceanic conditions associated with El Niño cause changes in atmospheric circulation patterns, altering the monsoon flow and rainfall distribution. During El Niño years, Odisha may experience below-normal rainfall or even drought conditions.

The exact impact of El Niño on the monsoon in Odisha can vary depending on the strength and duration of the El Niño event. Moderate to strong El Niño events often result in a more substantial weakening of the monsoon, leading to below-average rainfall and drought-like conditions. Weaker El Niño events may have a milder impact but can still result in below-normal rainfall.

It is important to note that El Niño is just one of several factors that can influence the monsoon in Odisha. Other climate patterns and oscillations, such as the Indian Ocean Dipole (IOD) and the Madden-Julian Oscillation (MJO), also play a role in modulating monsoon activity. Therefore, while El Niño is a significant factor to consider, it is not the sole determinant of monsoon performance in Odisha.

Overall, during El Niño years, there is a tendency for reduced rainfall and weaker monsoon conditions in Odisha. However, the specific impact can vary, and it is essential to consider multiple factors when assessing monsoon variability in the region.

Significance of Monsoon for Odisha

The monsoon season holds great significance for the state of Odisha in India. Here are some key points highlighting the importance of the monsoon for Odisha:

Agriculture: Odisha heavily relies on agriculture as a major sector of its economy, and the monsoon is crucial for agricultural activities. The rainfall received during the monsoon season ensures the irrigation of fields and water supply for crops. It plays a vital role in the growth of paddy, which is the primary crop of the state. The monsoon helps in replenishing water bodies, such as rivers, lakes, and reservoirs, which are essential for irrigation throughout the year.
Groundwater Recharge: Monsoon rainfall significantly contributes to recharging groundwater levels in Odisha. The state has many regions with a high dependence on groundwater for drinking water and agricultural needs. Adequate monsoon rainfall ensures the replenishment of groundwater reserves, which is essential for sustained water supply during the dry seasons.
Biodiversity: Odisha boasts diverse ecosystems, including forests, wetlands, and wildlife sanctuaries. The monsoon season brings abundant rainfall, which supports the growth and sustenance of these ecosystems. It promotes lush vegetation, rejuvenates rivers, and provides breeding grounds for various flora and fauna. The monsoon is particularly important for wetlands like the Chilika Lake, the largest brackish water lake in Asia, which witnesses an increase in water levels and supports a wide array of bird species during this season.
Reservoirs and Hydropower: Odisha has several reservoirs and dams that serve multiple purposes like irrigation, hydroelectric power generation, and flood control. The monsoon rainfall helps in maintaining and replenishing the water levels in these reservoirs, ensuring a steady supply of water for irrigation and power generation throughout the year. It also helps in the production of hydroelectricity, which contributes to the state’s energy requirements.
Cultural Significance: Monsoon holds cultural significance in Odisha as well. The state celebrates festivals like Raja Parba, which signifies the arrival of monsoon and celebrates fertility and womanhood. The festival is marked by cultural events, folk dances, and feasts.

Extreme Winter in Odisha

Odisha, being located in a tropical region, generally experiences a moderate winter season compared to the colder northern parts of India. However, there can be occasional instances of extreme winter conditions in Odisha, although they are relatively rare. Here is a detailed analysis of extreme winter in Odisha:

1. Low Temperatures

During extreme winter events, the temperatures in Odisha can drop significantly, sometimes reaching single-digit or near-freezing levels.
The severity and duration of these extreme cold spells may vary from year to year.
However, it is important to note that what is considered extreme in Odisha might still be milder compared to the winter conditions experienced in other parts of the country.

2. Factors Influencing Extreme Winter

Extreme winter conditions in Odisha can be influenced by several factors, including:

Northward Intrusion of Cold Air Masses: Occasionally, cold air masses originating from the northern regions of India or even as far as Central Asia can intrude into Odisha, leading to a drop in temperatures.
Western Disturbances: Western disturbances, which are extra-tropical weather systems originating in the Mediterranean region, can bring cold and moist air to Odisha. These disturbances often result in rainfall or snowfall in the northern and hilly regions of India but can also contribute to colder conditions in Odisha.
Advection of Cold Air from the Bay of Bengal: Winds blowing from the Bay of Bengal during the winter season can carry colder air towards Odisha, leading to a decrease in temperatures.

3. Duration and Impact

Extreme winter conditions in Odisha are generally short-lived compared to the prolonged winters experienced in the northern regions.
These episodes can last for a few days to a couple of weeks.
The impact of extreme winter in Odisha is usually limited to discomfort caused by the cold temperatures, particularly during the early morning and late evening hours.

4. Effects on Agriculture and Daily Life

Extreme winter conditions in Odisha can have some implications for agriculture and daily life, although they are relatively minor compared to the northern states. Some of the effects may include:

Crop Damage: If the extreme cold coincides with sensitive growth stages of certain crops, there may be some damage to crops like vegetables, fruits, and winter-sown crops.
Health Concerns: During extreme winter episodes, people may face health issues related to cold weather, such as respiratory problems, common colds, or discomfort due to low temperatures.
Increased Energy Consumption: The demand for heating and insulation may rise during extreme winter conditions, leading to increased energy consumption.

Note: It is important to note that extreme winter events in Odisha are relatively infrequent, and the state generally experiences a milder winter compared to other regions of India. The impact and severity of extreme winter conditions in Odisha may vary from year to year and are usually not as pronounced as in the colder northern states.