At 24.29 degrees, India experienced warmest August since 1901 : IMD

“As good rainfall activity was recorded during August, the persistent cloudy conditions pushed the minimum temperatures above normal. That is why, most areas of the country, particularly the central India region, recorded higher than average minimum temperatures,” said Mrutyunjay Mohapatra, director general, IMD.

As a result of such frequent low pressure systems, the country remained affected by a total of 16.5 low pressure-affected days in August.

Similarly, atleast two geographical regions — southern peninsular India and central India — experienced the warmest August in 123 years.

Last month, southern India received 203.4mm (6.6 per cent surplus) and the monthly average minimum temperature recorded here was 24.12 degrees (normal of 23.41 degrees). Central India received 359.6mm (16.5 per cent surplus) and the monthly average minimum temperature recorded was 24.26 degrees Celsius (23.71 degrees). August this year was the fourth warmest over east and northeast India and northwest India, the IMD officials said.

The all-India rainfall for August ended with a surplus of 15.3 per cent. This was the second highest August rainfall over the country since 2019, the IMD data stated.

At the end of three months of the southwest monsoon season, the country had recorded was 749mm, which was 7 per cent surplus. Last month, the country experienced a total of 753 rainfall incidents categorized as ‘very’ heavy (115.6 – 204.4mm in 24-hours), the second highest recorded since 2020 (1,008).

A comparison of August rainfall over India for the past six years showed that the monthly rainfall performance was the highest in 2019 followed by 2024. Significantly high rainfall deficits were recorded during 2021 and 2023 (see box I). The region-wise rainfall performance during the 2019 – 2024 showed a worrying trend over the northeast and northwest India regions. The data also concluded that Manipur has not received normal rainfall during August since 2019. Whereas, Bihar and Nagaland rainfall deficits during four out of the total six August months. Arunachal Pradesh recorded deficient rainfall during 2021, 2022 and 2024 (see box II).

The low pressure systems mainly were responsible for causing extremely heavy rainfall (more than 200mm in 24 hours) over Tripura, Rajasthan and Gujarat during the latter half of the month, said Mrutyunjay Mohapatra, director general, IMD. The IMD said that the wettest areas included Bagafa (Tripura) – 494mm, Khambhalia (Gujarat) – 430mm and Karauli (east Rajasthan) – 380mm.

Another positive contributor for the enhanced rainfall was the favourable phase of the Madden Julian Oscillation (MJO) – an eastward propagating, rain-bearing wind stream.

All these factors fed towards a continuous rainfall activity, so much so that the climatological monsoon ‘break’ phase was missed during August. Generally, the monsoon enters a break phase in the second week of August and during this brief break, the rainfall activity largely shifts to and remains concentrated over the foothills of the Himalayas and the northeast India region. At the same time, all other regions experience dry days.

Region-wise rainfall (in %) during August (2019 – 2024)

Source: IMD

Most rain-deficient (in %) states / UTs during August-2024 and their past records

*Normal rainfall

Source : IMD

*Anjali Marar is a science communicator at the Raman Research Institute.