The Climate Research and Services (CRS) of the India Meteorological Department (IMD) issued a ‘Statement on Climate of India during 2020’ in January 2021. As per the statement, 2020 was the eighth warmest year on record since nation-wide records started in 1901, on the basis of data of 1981–2010. It reveals that the annual mean land surface air temperature was on an average +0.29 °C above normal over India in 2020. But it is substantially lower than the highest warming (+0.71 °C), observed over the country during 2016. This increase in temperature is mainly attributed to the monsoon and post-monsoon seasons with mean temperature anomalies (actual temperature – normal temperature) of +0.43 °C and +0.53 °C respectively. During the winter, mean temperature was also above normal with anomaly of +0.14 °C, whereas during the pre-monsoon season, temperature was below normal (-0.03 °C).
The 2020 annual rainfall over the country as a whole was 109 per cent of its long period average (LPA) based on the data of 1961–2010. Overall, the monsoon season rainfall was 109 per cent of its LPA (above normal) over the country.
Temperatures
As per the statement, the five warmest years were: 2017 (+0.541 °C), 2016 (+0.71 °C), 2015 (+0.42 °C), 2010 (+0.539 °C), and 2009 (+0.55 °C). Notably, 12 out of 15 warmest years were during 2006 and 2020. With anomalies of 0.23 °C/ 0.34 °C, past decade, i.e., 2001–2010 or 2011–2020 was also the warmest decade. During 1901–2020, the average annual mean temperature across the country showed an increasing trend of 0.62 °C per 100 years with significant increasing trend (0.99 °C per century) in maximum temperature and relatively lower increasing trend (0.24 °C per century) in minimum temperature.
Similarly, the average country-wide mean monthly temperatures were warmer than the normal during the year except March and June. July was the fifth warmest with 0.56 °C; August, second warmest with 0.58 °C; September, warmest since 1901 with 0.72 °C; October, third warmest with 0.94 °C; and December, with 0.39 °C.
Rainfall
Country-wide, the annual rainfall was 109 per cent of LPA of 117.7 cm. During the June–September (southwest monsoon season, the principal rainy season of the country), rainfall was 109 per cent of LPA 88 cm (above normal). During this same period, seasonal rainfall was 115 per cent, 129 per cent, 106 per cent, and 84 per cent of its LPA in the four broad geographical regions of the country—Central India, South Peninsular, East, and Northeast India respectively.
During the October–December, the 2020 northeast monsoon season rainfall as a whole was 101 per cent of LPA (normal) over the country. Over the core region of the south peninsula, including 5 sub-divisions, namely coastal Andhra Pradesh, Rayalaseema, Tamil Nadu & Puducherry, South Interior Karnataka, and Kerala, the seasonal rainfall during the northeast monsoon season was also 110 per cent of LPA (normal). Except Kerala, all the sub-divisions received excess or normal rainfall.
Tropical Storms and High Impact Weather Events
Five cyclones were formed over the North Indian Ocean during 2020:
1. Amphan (a super cyclonic storm and most devastating) formed in the pre-monsoon season and crossed West Bengal coast over Sundarbans on May 20, 2020, over the Bay of Bengal.
2. Nivar (very severe cyclonic storm) crossed Tamil Nadu & Puducherry coasts close to north of Puducherry on November 25, 2020 (night), over the Bay of Bengal.
3. Gati (very severe cyclonic storm) formed during the post-monsoon season on November 21, 2020, over the Arabian Sea.
4. Nisarga (a severe cyclonic storm) crossed Maharashtra coast on June 03, 2020, over the Arabian Sea.
5. Burevi (a cyclonic storm) made landfall in Tamil Nadu on December 4, 2020, over the Bay of Bengal.
The country also witnessed some other high impact weather events, such as extremely heavy rainfall, floods, landslide, thunderstorm, lightning, cold waves, etc. These extreme weather events mainly affected the states of Bihar, Uttar Pradesh, Kerala, Telangana, Maharashtra, Himachal Pradesh, and Andhra Pradesh.