Climate of Odisha

Climate of Odisha: Odisha, located on the eastern coast of India, experiences a diverse and dynamic climate influenced by its geographical location, topography, and proximity to the Bay of Bengal. The state falls within the tropical monsoon climate zone, characterized by hot summers, substantial monsoonal rainfall, and mild winters. Odisha’s climate is profoundly shaped by the seasonal shifts in the southwest monsoon winds, which bring the majority of the state’s annual rainfall, making it crucial for agriculture and water resources.

With a coastline stretching over 480 kilometers, Odisha is also prone to cyclonic storms, particularly during the post-monsoon season, which significantly impact its coastal regions. Additionally, variations in temperature, humidity, and rainfall patterns across the state’s diverse landscapes—ranging from coastal plains to interior hilly areas—add to the complexity of Odisha’s climate. This intricate climatic system plays a pivotal role in the socio-economic life of the people, influencing agriculture, livelihoods, and disaster management strategies in the region.

Understanding the climate of Odisha is essential for planning and managing the state’s agricultural productivity, water resources, and disaster preparedness, as the region is highly vulnerable to both extreme weather events and climate change.

Climate of Odisha

Odisha experiences a tropical monsoon climate, with its weather significantly influenced by its coastal proximity to the sea. This results in hot summers, warm and humid monsoons, and mild, pleasant winters. Despite these seasonal variations, the state’s overall climate remains relatively moderate and consistent throughout the year.

Odisha experiences three main seasons which are discussed below:

Summer Season

• The summer season in Odisha begins in March and lasts until June, characterized by high temperatures. During this period, the maximum temperature often exceeds 40°C.
• In the western districts of Odisha, including Sundargarh, Sambalpur, Baragarh, Balangir, Kalahandi, and Mayurbhanj, temperatures consistently range between 40°C and 46°C for most of the year.

Rainy Season

• The monsoon season in Odisha begins in July and lasts until mid-October. Rainfall variability in the northern and northeastern parts of the state is less than 15%, while in the southern and southwestern regions, it increases to 15-20%.
• Odisha receives its monsoon rainfall from the southwest monsoon, which arrives on the coastal plains between June 5th and June 10th. By July, the entire state comes under its influence, and by mid-October, the southwest monsoon withdraws completely.
• During this season, the coastal areas are prone to cyclones and tornadoes. The state receives an average rainfall of around 200 cm, primarily between July and September, with July being the wettest month. Heavy rains during this period can cause major rivers to flood.
• Humidity levels are high during the monsoon, with relative humidity in coastal areas around 75%, while inland regions maintain about 60%.

High Annual Rainfall Regions:

• The northern regions of Odisha, including the catchment basins of the Budhabalanga, Baitarani, Brahmani, and Ib (a tributary of the Mahanadi), receive high annual rainfall (above 155 cm). These areas include Mayurbhanj, northern and western Kendujhar, Lahara sub-division of Angul, Sundargarh, and eastern Sambalpur. Cyclones during the monsoon season contribute to this high rainfall.
• Southeast Odisha also receives significant rainfall, particularly in a horseshoe-shaped area around the lower reaches of the Brahmani and Mahanadi rivers, encompassing Bhadrak, Sukinda, Kendrapara, and Cuttack.

Low Annual Rainfall Regions:

• Low annual rainfall regions (135 cm or less) are primarily located in southeastern Odisha.
• These areas include the catchment basins of the Vamsadhara and Rushikulya rivers, a small stretch east of Lake Chilika, eastern Koraput, Ganjam, western Puri district, the upper Tel basin, the Baragarh uplands, and the middle Brahmani basin. These regions do not lie directly in the path of cyclones or southwest monsoon winds from the Bay of Bengal.

Winter Season

• The winter season in Odisha begins in mid-October and lasts until February. In the coastal areas, temperatures range from 25°C to 18°C, moderated by the sea’s influence. In the interior regions, however, temperatures can drop as low as 7°C. Winter is generally mild, except in certain areas like Koraput and Kandhamal, where the minimum temperature may fall to 3-4°C.
• The state experiences light rainfall during October and November, while January and February remain mostly dry. Southern and western parts of Odisha may also experience occasional thundershowers during the winter months.

Local Seasonal Divisions in Odisha

Although Odisha traditionally experiences three main seasons—summer, monsoon, and winter—the local culture divides the year into six distinct seasons, each corresponding to specific months of the Hindu calendar. These six seasons, or “Ritus,” reflect the intricate relationship between Odisha’s natural environment and its cultural practices.

1. Grishma (Summer) – Vaisakha and Jyestha (mid-April to mid-June): Grishma marks the intense summer heat in Odisha, with temperatures soaring above 40°C in many parts of the state. This season is characterized by dry, hot weather and occasional heatwaves. The land becomes parched, and the rivers and water bodies begin to shrink. People adapt to the heat by wearing light cotton clothing and consuming cooling drinks such as “pakhala” (fermented rice water).
2. Barsa (Rainy Season) – Ashadha and Sravana (mid-June to mid-August): Barsa, or the monsoon season, begins with the arrival of the southwest monsoon. Heavy rains rejuvenate the land, bringing relief from the oppressive summer heat. Agriculture, especially paddy cultivation, flourishes during this period as the monsoon rains provide vital water for crops. However, the season is also marked by high humidity and occasional flooding in low-lying areas. Coastal regions are often on alert for cyclones during this time.
3. Sharad (Autumn) – Bhadraba and Aswina (mid-August to mid-October): Sharad is the post-monsoon period, characterized by clear skies and a drop in humidity. The land begins to recover from the monsoon rains, and this season is a time of agricultural harvest, particularly for paddy. The cooler, pleasant weather is marked by major festivals, such as Durga Puja and Navaratri, which are celebrated with great enthusiasm across the state.
4. Hemanta (Pre-Winter) – Kartik and Margasira (mid-October to mid-December): Hemanta signals the onset of cooler weather in Odisha. The temperature begins to drop, particularly in the interior and hilly regions. The air becomes drier, and the evenings are notably cooler. This season marks the end of the agricultural harvest, and preparations begin for the winter months. Festivals like Kartika Purnima and Boita Bandana are celebrated, symbolizing Odisha’s ancient maritime heritage.
5. Sisira (Winter) – Pausa and Magha (mid-December to mid-February):Sisira represents the peak of the winter season. Coastal areas experience mild winter conditions, while interior regions, particularly in Koraput and Kandhamal, see a significant drop in temperature, sometimes falling to as low as 3°C to 4°C. The weather is generally dry, and mornings are often foggy. Traditional activities like “Makar Sankranti” and “Pongal” are observed during this time.
6. Basanta (Spring) – Falguna and Chaitra (mid-February to mid-April):Basanta marks the arrival of spring, a season of renewal and growth. Temperatures begin to rise, but the heat is still moderate, making it one of the most pleasant times of the year. This season is associated with blooming flowers, especially the “palaash” or flame of the forest, and a general sense of rejuvenation. The vibrant festival of Holi is celebrated during this season, adding to the color and festivity of the time.

These six seasons reflect the rhythms of Odisha’s natural environment, influencing its agriculture, festivals, and daily life, creating a unique blend of cultural and environmental harmony.

Rainfall in Odisha

Rainfall in Odisha primarily occurs during the monsoon and winter seasons. A detailed account of the state’s rainfall patterns is outlined below:

Monsoon Rainfall

Monsoon rainfall is the most significant in Odisha as it directly impacts agricultural productivity, particularly crop cultivation. When the monsoon rainfall exceeds 140 cm, it is considered high, while rainfall below 120 cm is regarded as low, which can be insufficient for a good paddy harvest.

High Monsoon Rainfall Regions:

• The Ib River basin and parts of the northern Baitarani basin, including eastern Sambalpur, western Sundargarh, and the Sadar sub-division of Keonjhar district, receive high rainfall during the monsoon.
• The Phulbani and Phiringia regions also experience substantial rainfall during this season.

Low Monsoon Rainfall Regions:

• The southwestern regions of Odisha generally receive lower rainfall during the monsoon.
• Parts of the middle Baitarani basin, extending to the northeastern areas of Talcher, also experience low rainfall during this period.

Winter Rainfall

Winter rainfall in Odisha, though less frequent, plays an important role in supporting the growth of rabi crops. A total rainfall of more than 5 cm is considered high winter rainfall, while less than 2.5 cm is categorized as low winter rainfall.

High Winter Rainfall Regions:

• Northern Odisha, from Baripada in the east to Sundargarh in the west, receives higher winter rainfall. This region includes northeastern Sambalpur, northern Keonjhar, most of Mayurbhanj, and the central parts of Balasore district.
• Coastal areas like Puri and Khurda also receive more than 5 cm of rainfall during winter.
• The Phulbani and Phiringia plateaus are known for receiving high winter rainfall as well.

Low Winter Rainfall Regions:

• The southwestern parts of Odisha, particularly Koraput district, experience low rainfall during the winter. This region is primarily a single-crop zone due to the limited rainfall.

Climatic Regions of Odisha

Various geographers have provided different classifications for Odisha’s climate, each using distinct methodologies to capture the region’s climatic nuances. Below are the key classifications:

1. Köppen’s Classification: Tropical Savannah (Aw): According to Köppen’s widely recognized climate classification, Odisha’s climate falls under the Tropical Savannah (Aw) category. This classification is characterized by a distinct dry season in winter and a wet season during the monsoon. The “Aw” designation signifies a tropical climate where winters are dry and temperatures remain consistently high throughout the year. Odisha’s location in the tropical belt, along with its pronounced monsoon season and relatively mild winter, aligns it with this tropical savannah climate type. This classification underscores the state’s hot summers, heavy monsoons, and dry winters, making it agriculturally dependent on seasonal rainfall.

2. Thornthwaite’s Classification: Sub-Humid with Deficient Winter Rains: In contrast to Köppen’s approach, Thornthwaite’s classification focuses more on moisture availability and water balance. Under this system, Odisha’s climate is classified as sub-humid with deficient winter rains. This means that while the state receives sufficient rainfall during the monsoon season, there is a significant shortage of rainfall in the winter months, which contributes to drier conditions during this period. Thornthwaite’s classification emphasizes the seasonal imbalance in moisture distribution, making it particularly relevant for understanding Odisha’s agricultural cycles, where winter rains are insufficient to support rabi crops without irrigation.

3. SB Chatterjee’s Classification: Coastal Tropical Savannah: SB Chatterjee’s classification further refines the understanding of Odisha’s climate by distinguishing the coastal region. According to Chatterjee, the coastal region of Odisha experiences a Tropical Savannah climate similar to Köppen’s classification. However, this approach highlights the specific climatic patterns of the coastal areas, where the moderating influence of the Bay of Bengal results in relatively higher humidity, milder temperature variations, and more frequent cyclonic activity. The coastal climate, while still characterized by seasonal rainfall, is less extreme in terms of temperature than the interior regions, providing a more nuanced understanding of the climatic variation across the state.

These varied classifications offer different perspectives on Odisha’s climate, from its tropical savannah nature to its sub-humid characteristics and specific coastal influences. Together, they provide a comprehensive understanding of the region’s weather patterns and their impact on agriculture, livelihoods, and natural hazards such as cyclones and droughts.

Agro-Climatic Zones of Odisha

Odisha is divided into ten distinct agro-climatic zones by Forest and Environment department of Odisha, based on variations in soil type, rainfall, temperature, topography, and vegetation. These agro-climatic zones help in planning and optimizing agricultural activities suited to the specific environmental conditions of each region. Below is an overview of the agro-climatic zones in Odisha:

1. North Western Plateau Zone

• Districts Covered: Sundargarh, Jharsuguda, Northern parts of Sambalpur, and Deogarh.
• Characteristics: This zone is characterized by undulating terrain with a hot and moist climate. The soil is predominantly red and lateritic, making it suitable for crops like paddy, maize, and pulses. The region receives moderate rainfall, but due to undulating topography, water retention is a challenge.

2. North Central Plateau Zone

• Districts Covered: Mayurbhanj, Keonjhar.
• Characteristics: This zone has a varied topography, with a hot and humid climate. Soils are a mix of red, lateritic, and alluvial types. Paddy is the major crop grown, along with pulses and oilseeds. The area receives high rainfall, supporting rain-fed agriculture.

3. North Eastern Coastal Plain Zone

• Districts Covered: Balasore, Bhadrak, Jajpur, Kendrapara.
• Characteristics: The coastal plains are characterized by a humid climate and alluvial soils. This zone is highly fertile and suitable for paddy, groundnut, vegetables, and pulses. It benefits from irrigation facilities but is prone to cyclones and waterlogging due to its proximity to the coast.

4. East and South Eastern Coastal Plain Zone

• Districts Covered: Puri, Khurda, Jagatsinghpur, Cuttack.
• Characteristics: This coastal region experiences a humid climate with saline and alluvial soils. Agriculture is heavily influenced by monsoons and cyclonic rains. Rice is the main crop, along with vegetables, pulses, and oilseeds. The region has good irrigation infrastructure but is vulnerable to cyclones and tidal flooding.

5. North Eastern Ghat Zone

• Districts Covered: Ganjam, Gajapati.
• Characteristics: A hilly terrain with red and lateritic soils, this zone experiences a hot and humid climate. Rain-fed crops like millet, pulses, and oilseeds are commonly grown. The region also supports horticulture, particularly fruits like mango, pineapple, and cashew.

6. Eastern Ghat High Land Zone

• Districts Covered: Rayagada, Kandhamal, Koraput, Malkangiri, and parts of Gajapati.
• Characteristics: This hilly and tribal-dominated region has red and lateritic soils. The climate is cooler compared to other parts of Odisha, with significant rainfall. It is suitable for growing rice, millets, pulses, and horticultural crops like coffee, turmeric, and ginger. The region is also known for its forests and minor forest produce.

7. South Eastern Ghat Zone

• Districts Covered: Koraput, Nabarangpur, Malkangiri.
• Characteristics: This zone is mountainous with red and black soils. The region has a cooler climate and receives heavy rainfall, making it suitable for rice, maize, ragi, pulses, and oilseeds. The region also has potential for horticultural crops and plantation crops like coffee and cashew.

8. Western Undulating Zone

• Districts Covered: Balangir, Sonepur, Bargarh, parts of Sambalpur, Boudh.
• Characteristics: This zone experiences a hot and dry climate with undulating terrain. The soil type varies from red and yellow to lateritic, and the region is prone to droughts. Rain-fed crops such as millets, pulses, and oilseeds are cultivated, along with cotton and maize.

9. Western Central Table Land Zone

• Districts Covered: Parts of Sambalpur, Angul, Bargarh, and Dhenkanal.
• Characteristics: This plateau region has red and yellow soils with a hot and dry climate. Paddy, pulses, and oilseeds are commonly grown, along with horticultural crops like fruits and vegetables. The region also has potential for floriculture.

10. Mid Central Table Land Zone

• Districts Covered: Parts of Nayagarh, Boudh, Phulbani.
• Characteristics: This zone has a hot and dry climate with red and yellow soils. It is suitable for crops like paddy, pulses, oilseeds, and vegetables. The region also has potential for sericulture and other allied agricultural activities.

These agro-climatic zones play a crucial role in guiding agricultural practices, enhancing crop productivity, and optimizing the use of resources based on the distinct environmental conditions of each zone. They help tailor agricultural planning to suit the soil type, climate, and water availability, promoting sustainable and region-specific farming practices.

Cyclones in Odisha

A cyclone is a massive rotating system of air characterized by low pressure at its center, surrounded by a high-pressure air mass. In the Northern Hemisphere, cyclones rotate counterclockwise, while in the Southern Hemisphere, they rotate clockwise. Odisha, being a coastal state, frequently experiences cyclonic storms, which have become a regular occurrence due to its location along the Bay of Bengal. These tropical cyclones often result in significant destruction.

One of the most devastating cyclones to hit Odisha occurred between October 25th and November 4th, 1999. Known as the Odisha Super Cyclone, it caused widespread destruction and severe flooding.

Other notable cyclones that have impacted Odisha include:

1. 1999 Super Cyclone: This was one of the most devastating cyclones in Odisha’s history, hitting on October 29, 1999. It caused extensive damage and resulted in over 10,000 fatalities.
2. Cyclone Phailin (2013): This powerful cyclone made landfall near Gopalpur, causing widespread destruction, especially in Ganjam, Puri, and Khordha districts.
3. Cyclone Hudhud (2014): Although it primarily affected Andhra Pradesh, it also caused significant damage in Odisha, particularly in the southern parts.
4. Cyclone Titli (2018): This cyclone made landfall near Gopalpur and caused severe damage, especially in Ganjam, Gajapati, and Puri districts.
5. Cyclone Fani (2019): This extremely severe cyclonic storm hit Puri with wind speeds of around 175 km/h, causing massive destruction and significant economic losses.
6. Cyclone Yaas (2021): This cyclone made landfall near Balasore, causing heavy rainfall and flooding in several districts.

These cyclones have had a profound impact on the state’s infrastructure, economy, and communities.

Conclusion

In conclusion, Odisha’s climate is predominantly tropical, characterized by high temperatures, humidity, and distinct monsoon patterns. The coastal location of the state makes it particularly vulnerable to cyclonic storms, especially during the monsoon and post-monsoon periods. These cyclones, along with the variations in rainfall and occasional droughts in the interior regions, significantly impact the state’s agriculture, economy, and infrastructure. As climate patterns continue to evolve, Odisha faces the dual challenge of adapting to its natural climatic conditions while mitigating the effects of increasingly unpredictable weather events.