Delhi's August sees above-normal rain, warm nights and three-year-high AQI

The capital also recorded its wettest first week of August in 15 years, receiving 127 mm of rainfall during the first seven days of the month.

From rain-soaked days to warm nights, August has unfolded differently for Delhi this year: Rainfall has already crossed the seasonal average, day and night-time temperatures remain high, and the month's average air quality index has reached a three-year high.

The capital also recorded its wettest first week of August in 15 years, receiving 127 mm of rainfall during the first seven days of the month, the highest for the period since 2011. (Sunil Ghosh/ HT Photo)

According to the India Meteorological Department (IMD), Delhi has received 653.9 mm of rainfall at Safdarjung since the beginning of the monsoon season, compared with the long-period average of 506.7 mm, resulting in a surplus of 147.2 mm, or 29 per cent.

The capital also recorded its wettest first week of August in 15 years, receiving 127 mm of rainfall during the first seven days of the month, the highest for the period since 2011. The month witnessed one of its heaviest single-day rainfall spells on August 25, when Safdarjung recorded 99.1 mm of rain in 24 hours, the highest rainfall for an August day in two years, the IMD said.

The last time Safdarjung recorded more rainfall in August was on August 1, 2024, when the station received 107.6 mm. The seasonal rainfall surplus has been recorded across most of the city's weather stations.

Palam received 533.2 mm against its seasonal normal of 482.1 mm, a surplus of 11 per cent, while Lodhi Road recorded 648.2 mm against 506.7 mm, 28 per cent above normal.

The Ridge recorded 703.1 mm against its normal of 432.1 mm, a surplus of 63 per cent, while Ayanagar received 686.3 mm against 431.3 mm, 59 per cent above normal.

August was considerably wetter than normal. Safdarjung recorded 354.1 mm during the month against the normal of 222.9 mm, a surplus of 131.2 mm or 59 per cent. Palam received 300.8 mm against its August normal of 207.6 mm, 45 per cent above normal, while Lodhi Road recorded 332 mm against 222.9 mm, a surplus of 49 per cent, the IMD said.

The Ridge received 357.4 mm against its August normal of 181.3 mm, nearly 97 per cent above normal, while Ayanagar recorded 383.2 mm against 179.2 mm, a surplus of 114 per cent, it said.

Despite the frequent showers, temperatures remained high.

The average maximum temperature at Safdarjung until August 29 was 34.1 degrees Celsius, the highest in two years. The IMD said the last time the average maximum temperature was higher was in 2023, when it stood at 35.4 degrees Celsius.

In 2024, it was 34.1 degrees Celsius.

The average minimum temperature stood at 26.8 degrees Celsius, the same as in 2023 and the highest since then. The last time it was higher was in 2018, when the average minimum temperature was 27.3 degrees Celsius.

The air quality also remained a mixed bag throughout the month.

An analysis by the Centre for Research on Energy and Clean Air found Delhi's average air quality index (AQI) for the 28 days of August stood at 92, the highest since 2023. It said despite the elevated monthly average, 19 of the 28 days were in the satisfactory category, while the remaining nine days were moderate. In August 2023, eight days were in the satisfactory category, while 23 were moderate.

The maximum AQI this August also reached 129, the highest since 2023, when the maximum was 186.