Subscribe
Nights across India in September 2025 were unusually warm, with minimum temperatures climbing well above the long-term norms, according to the India Meteorological Department’s (IMD) monthly climate summary released on October 8.
For the country as a whole, the average minimum temperature in September 2025 was 23.44 degrees Celsius (°C), which is 0.63 °C above the 1991-2020 normal of 22.80°C. Meanwhile, the mean temperature (daily average of max and min) was 27.51°C, 0.39°C above its normal of 27.12°C.
In comparison, the average maximum temperature was 31.58°C only 0.15°C above normal and well within a ‘normal’ range, suggesting that it was probably night-time warmth, more than daytime heat, driving the temperature anomaly.
These elevated minimum and mean temperatures place September 2025 among the warmest on record for night‐time conditions. Since 1901 (when record keeping began), the September average minimum temperature ranked as the fifth highest for the country, while the mean temperature was the seventh highest. In contrast, the average maximum ranks the 23rd highest nationally.
Analysis of Down To Earth’s daily ‘heat tracker’ data for the month of September also showed that out of 35 cities, half of them had 20 or more days with above normal minimum temperatures. This meant these cities experienced above normal night temperatures for over 65 per cent days in a month.
Diu had 29 such days when nigh-time temperatures were above normal, followed by Patna, Srinagar, and Lucknow with 26 days. Other cities included Jammu, Dehradun, Guwahati, Panjim, Ranchi, Bhopal, Imphal, Kohima, Ludhiana, Jaipur, Gangtok, Agartala, and Kolkata.
In contrast, only 10 cities had above normal maximum temperatures in September.
Heat tracker tracks data for major cities of 28 states and 8 Union territories. The data is sourced from IMD. Data for Puducherry, however, only shows daily maximum and minimum temperature and not the normal for the corresponding period.
Meanwhile, the IMD climate summary highlighted that the night-time temperatures were even more pronounced in the east and Northeast India region. The region recorded an average minimum temperature of 24.52°C, which is 0.82°C above normal, ranking as the third- highest since 1901.
However, the region experienced more than normal heat both day and night. The average maximum temperature there was 32.31°C, with a departure from normal of above 1.59°C, also the third-highest on record for the region.