India Climate 2025: 99% of days in January-September experienced extreme weather

With the global average concentration of carbon dioxide (CO2) from human activities recording the largest increase since measurement started in 1957, the world is experiencing perilously increasing extreme weather events — contrasting and in unusual geographies.

Nearly every day during January-September 2025, India recorded an extreme weather event, according to the annual “Climate India 2025” assessment released by the Centre for Science and Environment (CSE) and Down To Earth magazine.

“India faced extreme weather events on 99 per cent of days in the first nine months of this year, marked by heat and coldwaves, lightning and storms, heavy rain, floods and landslides,” says the assessment.  Of the 273 days, in 270 days extreme weather events were recorded.

The UN Intergovernmental Panel on Climate Change (IPCC) defines extreme weather events as occurrences that are “rare at a particular place and time of year”.

While India does not have an official definition, the India Meteorological Department (IMD), in its annual “Statement of Climate of India” reports, classifies lightning and thunderstorms, heavy to very heavy, and extremely heavy rainfall, landslides and floods, coldwaves, heatwaves, cyclones, snowfall, dust and sandstorms, squalls, hailstorms and gales as extreme weather events.

IMD defines each of these weather events on its website “Climate Hazards and Vulnerability Atlas of India”, launched in January 2022, and in other documents.

The “Climate India” annual assessment uses data from various government sources and media reports to assess the frequency of such events. The CSE-Down To Earth’s Data Centre tracks such events every day and makes the assessment month- and season-wise. The latest assessment has covered the January-September 2025 period.

The assessment brings out not just the rising frequency but also the spread of extreme weather events in India. All the 36 states and Union Territories reported extreme weather events, a first in the last four years.

“India experienced extreme weather events every day for 7 of the 9 months. They are February, April, May, June, July, August and September,” the assessment says. Thirty states/UTs recorded extreme weather events for eight consecutive months — February to September 2025.

Himachal Pradesh recorded the highest number of days with extreme weather events among the states — 217 days out of 273 under assessment of the CSE-Down To Earth Data centre. Kerala follows MP with 147 days and Madhya Pradesh with 144 days.

Region-wise, Northwest India recorded the most days with extreme weather events — 257 days out of 273. This region, as defined by the “Climate India 2025” assessment, comprises Chandigarh, Delhi, Haryana, Himachal, J&K, Ladakh, Punjab, Rajasthan, Uttar Pradesh, and Uttarakhand.