India records its warmest March days in 121 years

India, on average, recorded its warmest March days in 121 years with the maximum temperature across the country clocking in at 1.86°C above normal, an analysis by the India Meteorological Department (IMD) has shown.

The record-breaking figure was driven by large deviations in the maximum temperature in northwest and central India. While the northwest region recorded its highest average maximum, central recorded its second warmest March in terms of day temperatures for the month since 1901.

The figures illustrate the scale of the temperature aberration, which effectively heralded the beginning of summer for most parts of the country. Northwest and central India recorded heatwaves during the second half of March.

Experts said the trend, the outcome of unusual wind patterns, could be linked to the climate crisis. “Lack of rainfall is one reason for this heat. There were two heatwave events also in the month of March. There was an anti-cyclonic circulation which led to advection of heat from the western side to north and central India. Overall global warming is also one of the main reasons. Even during La Nina events we are often recording very high temperatures,” said OP Sreejith, head, climate monitoring and prediction group, IMD, Pune.

“The primary reasons behind such high-temperature recordings in March this year was the lack of rainfall and consistent dry and hot, westerly winds blowing into northwest and central India. We also saw that cloudless skies also resulted in a direct exposure to the sun’s rays, which pushed the temperatures higher. In the first half of April too, similar weather conditions are likely to continue as there are no weather systems developing,” said Mahesh Palawat, vice-president (meteorology and climate change) at Skymet Weather Services.

The average maximum, minimum and mean temperature for the country as a whole during March 2022 were 33.10°C, 20.24°C and 26.67°C respectively, against the normal of 31.24°C, 18.87°C and 25.06°C, based on the averages for the period of 1981-2010.

Over northwest India, the average maximum temperature in March was the highest with a departure of 3.91°C above normal. The average minimum temperature – or night temperature — was the second highest since 1901 with a departure of 2.53°C above normal. The mean daily temperature was the second highest with departure of 3.22°C above normal.

Over Central India, this March was the second warmest in 121 years in terms of maximum temperatures; third warmest in terms of mean temperatures and fourth warmest in terms of minimum temperatures.

It was the warmest March for east and northeast India in terms of daily mean temperatures; second warmest when it comes to minimum temperatures and fourth warmest when it comes to maximum temperatures.

Only peninsular India ranked somewhat less aberrant temperatures: it was the ninth warmest March for southern states in maximum temperatures, fourth warmest in terms of mean temperature.

Rainfall data further supported how dry this March was – the country on average recorded the third lowest rainfall since 1901.

The country as a whole recorded 8.9 mm, which is 71% less than its long period average (LPA) of 30.4 mm recorded between 1961 to 2010. The last time there was scantier rain in March was in the years 1909 (7.2 mm) and 1908 (8.7 mm).

HT reported on March 31 that the number of heat wave days in a decade has increased from 413 in the 1981-90 decade to 575 in 2001-10 and further to 585 to 600 in 2010-20, highlighting the impact the climate crisis is having on maximum temperatures.

These are the findings of an ongoing study by the Kottayam based Institute for Climate Change Studies (ICCS) and India Meteorological Department. Heat wave trends for 1961 to 2010 period were published by the team of researchers in a book titled “Observed Climate Variability and Change Over the Indian Region” in 2016. The analysis is being presently updated.

In the hot weather season of April-June, most of the 103 weather stations being studied for heatwave occurrence in India have either recorded an increasing or a significantly increasing trend in heatwave frequency between 1961 to 2020.

In comparison to the 1961 to 1990 period, the regions with more than 8 heat wave days on an average in the April, May and June season has increased significantly spatially between 1991 to 2020 period based on spatial mapping by the institute.

“We will issue a statement on the synoptic features that have led to very high temperatures in March by tomorrow,” said KS Hosalikar, head, IMD Pune.