India records third warmest March in 121 yrs : IMD

The temperatures were above normal in all subdivisions of northwest, central, eastern and north-eastern India but in parts of peninsular India they were below normal.

The month of March this year was the third warmest in 121 years, after 2004 and 2010, with an average maximum temperature of 32.6 degree C, 1.4 degree C above normal, the India Meteorological Department said on Monday.

The monthly average maximum, minimum and mean temperature in March this year was 32.65 degree C, 19.95 degree C and 26.30 degree C respectively, against the normal of 31.24 degree C, 18.87 degree C and 25.06 degree C based on the climatology for 1981 to 2010 period, the IMD said. The temperatures were above normal in all subdivisions of northwest, central, eastern and north-eastern India but in parts of peninsular India they were below normal, the weather department added. In 2004, the average maximum temperature for March was 32.82 degree C and in 2010 it was 33.09 degree C.

Heat wave conditions were recorded in many parts of the country in March with severe heat wave at isolated places occurred over West Rajasthan during March 29 to 31. Heat wave conditions were recorded over east Rajasthan during March 30 to 31, over Odisha and adjoining parts of Gangetic west Bengal, Coastal Andhra Pradesh, Tamil Nadu on March 31. The highest maximum temperature of 44.6 degree C was recorded at Baripada, Odisha on March 30.

The months of January and February were also the third warmest since 1901 when mean temperatures are considered and the second warmest in the past 120 years when minimum or early morning temperatures are considered, the IMD said in its earlier report. Through January, February and March, La Nina, a global meteorological phenomenon was prevailing which is associated with colder winters and generally milder temperatures. But this year’s warming trend has possibly overshadowed the cooling effect of La Nina.

“One of the main reasons for record high temperatures being recorded since January is scanty rains. When there is less rain air is dry and warm,” said M Mohapatra, director general, IMD.

“It’s difficult to say why temperatures are so high despite La Nina conditions being moderate. La Nina has started weakening now. It is (the impact of) climate change signature on temperature patterns. You can see that temperatures in the south peninsula didn’t rise as much because of clouding and rain,” OP Sreejith, scientist, climate monitoring and prediction group had said in March about warmer than usual winter.

For April, IMD has forecast high probability of above normal maximum temperatures over most subdivisions of northwest, north along the plains of Himalayas, east, west and central India and below normal maximum temperatures over most subdivisions of south Peninsular India, northeast India and few subdivisions of extreme north India.

Western disturbance (WD) activity in March was higher than normal as a total of 7 WDs moved across Western Himalayan Region against the normal of four WDs. Out of 7 WDs, 3 WDs were very active and had moved as a cyclonic circulation but rainfall over the country as a whole for March was 16.7 mm, which is 45% less than its Long Period Average (LPA) of 30.4 mm. Week by week rainfall data in March 2021 shows that consecutively past four weeks in the season, India recorded deficient rainfall over the entire country.

All three active WDs, however, caused scattered to fairly widespread rainfall and thunderstorm activity over Western Himalayan region during the period and movement of these systems to eastward and formation of its induced cyclonic circulation over northwest Rajasthan in association with these WDs, caused isolated to scattered rainfall/thunderstorm activity over adjoining plains of northwest India during the same period. Dust raising strong surface winds prevailed during March 30 to 31 over parts of Punjab, Rajasthan, Haryana, Chandigarh, Delhi, Uttar Pradesh, Madhya Pradesh.

In March, moderate La Niña conditions were prevailing over equatorial Pacific and Sea Surface Temperatures (SSTs) were below normal over central & eastern equatorial Pacific Ocean. El Niño and the Southern Oscillation (ENSO) is a periodic fluctuation in sea surface temperature and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean according to the National Oceanic and Atmospheric Administration (NOAA).

ENSO has a major influence on weather and climate patterns such as heavy rains, floods and drought. El Niño has a warming influence on global temperatures, whilst La Niña has the opposite effect. In India for example, El Nino is associated with drought or weak monsoon while La Nina is associated with strong monsoon and above average rains and colder winters.