Meghalaya records warmest year since 1901 as monsoon falls 43 per cent short

• Meghalaya records its highest annual mean temperature since 1901 at 20.77°C.

• Southwest monsoon rainfall falls 43 per cent below normal, with July recording the largest deficit.

• IMD documents contrasting district-level rainfall trends alongside episodes of extremely heavy precipitation.

Meghalaya experienced its warmest year since 1901 in 2025, with the annual mean temperature climbing to 20.77°C, even as the state recorded a 43 per cent deficit in southwest monsoon rainfall, according to an India Meteorological Department (IMD) assessment.

The findings are contained in 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. Drawing on meteorological records dating back to 1901, the report examines long-term temperature trends, rainfall variations and extreme weather events across the state.

The annual mean temperature of 20.77°C was 0.96 degrees above the 1991-2020 long-period average. Both maximum and minimum temperatures remained above normal for much of the year. The annual minimum temperature was the highest recorded since 1901, while the maximum temperature ranked third highest.

The report places 2025 at the top of Meghalaya's five warmest years on record, followed by 2023, 2024, 2021 and 2022.

The longer-term trend is equally significant. Between 1901 and 2025, the state's annual mean temperature increased at a rate of 0.73°C per century. 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. Maximum temperatures during the season were 1.2 degrees above normal, making 2025 the warmest monsoon season on record in terms of maximum temperature since 1901.

Rainfall deficit despite extreme downpours

The record warmth coincided with a substantial shortfall in precipitation. Meghalaya received 73 per cent of its annual long-period average rainfall in 2025, while southwest monsoon precipitation — which normally accounts for 71.8 per cent of the state's annual rainfall — stood at just 57 per cent of the seasonal average.

Excess rainfall during the pre-monsoon season, which contributes around 19.1 per cent of annual precipitation, partly offset the deficit. However, rainfall remained predominantly below normal between June and October, with July recording the steepest shortfall.

The seasonal assessment found deficient rainfall during winter, monsoon and post-monsoon periods, while above-normal pre-monsoon precipitation helped limit the overall annual deficit.

There were considerable variations across districts. Of the 11 districts covered in the 2025 assessment, six recorded deficient rainfall, three received normal precipitation, one experienced large excess rainfall and another recorded a large deficiency.

South West Khasi Hills reported large excess rainfall, while West Jaintia Hills experienced a large deficit.

The IMD's standardised precipitation index (SPI), which measures the severity of wet and dry conditions, indicated mildly wet conditions only in East Garo Hills. The remaining districts experienced varying degrees of dryness.

Long-term rainfall patterns show regional divergence

The report also points to contrasting rainfall trends across Meghalaya over the longer term. An analysis of annual precipitation 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, however, were unavailable for this assessment.

The overall rainfall deficit did not prevent several parts of the state from experiencing intense spells of precipitation during 2025. The IMD documented heavy, very heavy and extremely heavy rainfall events at multiple monitoring stations, including Cherrapunji, Mawsynram and Shillong.

Some locations received more than 204.5 mm of rain within 24 hours, crossing the IMD's threshold for classifying precipitation as extremely heavy.

The assessment also recorded instances of flooding, lightning, thunderstorms, gale and hailstorm-related events during the year.

The combination of deficient seasonal rainfall and episodes of exceptionally intense precipitation underscores the uneven distribution of rainfall across the state, with prolonged dry spells coexisting with concentrated bouts of heavy downpour.

The IMD's assessment is intended to provide a scientific basis for planning across sectors such as agriculture, water management, power, public health and disaster management.

However, the report does not quantify the direct consequences of the 2025 temperature and rainfall patterns for crop yields, water availability or household livelihoods. Such impacts would require separate assessments by the relevant departments and researchers.

With PTI inputs