SHILLONG: Meghalaya recorded its warmest year since 1901 in 2025, with the annual mean temperature rising to 20.77 degrees Celsius, even as the state received 43 per cent below-normal southwest monsoon rainfall, according to an India Meteorological Department (IMD) report.
The annual mean temperature was 0.96 degrees Celsius above the 1991-2020 long-period average, making 2025 the warmest year in Meghalaya's recorded climate history. The report also found that the state's annual minimum temperature was the highest since 1901, while the maximum temperature ranked third highest.
The findings are part of the IMD's Statement on Climate for Meghalaya: 2025, prepared by its Climate Research and Services office in Pune in collaboration with the Meghalaya government. The assessment examines temperature trends, rainfall patterns and extreme weather events using climate records dating back to 1901.
According to the report, Meghalaya's annual mean temperature increased at a rate of 0.73 degrees Celsius per century between 1901 and 2025. Maximum temperatures rose faster, at 0.85 degrees per century, compared with 0.62 degrees for minimum temperatures.
The warming was particularly pronounced during the southwest monsoon, when maximum temperatures were 1.2 degrees Celsius above normal, making it the warmest monsoon season on record in terms of maximum temperature since 1901.
Despite the record warmth, the state experienced a significant rainfall deficit in 2025. It received only 73 per cent of its annual long-period average rainfall, while southwest monsoon precipitation stood at 57 per cent of normal. The monsoon accounts for 71.8 per cent of Meghalaya's annual rainfall.
Excess rainfall during the pre-monsoon season, which contributes around 19.1 per cent of the annual precipitation, partly offset the deficit. However, rainfall remained predominantly below normal from June to October, with July recording the highest deficiency. The winter, monsoon and post-monsoon seasons also experienced deficient rainfall.
A district-wise assessment of 11 districts showed that six received deficient rainfall, three recorded normal precipitation, one received large excess rainfall and another experienced large deficiency. South West Khasi Hills recorded large excess rainfall, while West Jaintia Hills reported large deficient rainfall.
The IMD's Standardised Precipitation Index (SPI), which measures wet and dry conditions, indicated mildly wet conditions only in East Garo Hills. The remaining districts experienced varying degrees of dryness.
The report also highlighted contrasting long-term rainfall trends. An analysis of annual rainfall between 1951 and 2024 showed an increasing trend in three adjoining districts in western Meghalaya, while the remaining districts recorded declining trends. Data for five districts were unavailable for this assessment.
Despite the overall rainfall deficit, several parts of the state experienced episodes of intense precipitation during 2025. Heavy, very heavy and extremely heavy rainfall events were recorded at multiple stations, including Cherrapunji, Mawsynram and Shillong. Some locations received more than 204.5 mm of rainfall in 24 hours, the IMD threshold for extremely heavy rainfall.
The assessment also documented floods, lightning, thunderstorms, gale and hailstorm-related events during the year, highlighting the uneven distribution and intensity of rainfall across the state.
The IMD said the assessment would provide a scientific basis for planning in sectors such as agriculture, water management, power, health and disaster management. However, it did not establish the direct impact of the 2025 temperature and rainfall patterns on crop yields, water availability or household livelihoods, which would require separate assessments.