Guwahati: Guwahati’s monsoon is becoming hotter and more uncomfortable, with a new India Meteorological Department (IMD) study finding that the city’s “feels-like” temperature reached a staggering 55.5°C in September during 2022–24.

The study, published in the October 2026 issue of MAUSAM, compared weather conditions in Guwahati during 2022–24 with the 1991–2020 climatological period. It found that extreme thermal discomfort has intensified, particularly during the monsoon months.

The study was authored by Sudip Kumar Kundu and colleagues from the Regional Meteorological Centre, IMD, Guwahati, and IMD, New Delhi.

What makes the finding striking is that the rise in heat is occurring alongside declining rainfall in July, August and September. The study’s analysis found temperatures rising while rainfall fell in these three months compared with the 1991–2020 period.

September emerges as the worst month

The Heat Index analysis showed a sharp rise in recent years, with the highest apparent temperature during 2022–24 reaching 55.5°C in September, followed by 53.6°C in July and 53.3°C in August. By comparison, the highest Heat Index recorded during 1991–2020 was 49.5°C in August.

The researchers found that September alone became about 6°C hotter in terms of perceived temperature during 2022–24 compared with the earlier climatological period. The study also found that the period classified as beyond “usually uncomfortable” had expanded, with April joining May to October in this category during 2022–24.

A hotter monsoon, with less rain

The rainfall-temperature relationship throws up another worrying signal.

According to the study’s Hythergraph analysis, July, August and September recorded less rainfall but higher temperatures during 2022–24 compared with 1991–2020. Temperatures also increased in several other months, including November through February.

That combination matters for agriculture. Hotter conditions increase water loss from crops, while declining soil moisture can affect crop development.

The study also flags possible impacts on flowering, pollination and fruit development.

The danger is not just on the thermometer

The study puts the heat in a human-health context. During July, August and September in 2022–24, Guwahati entered the “Extreme Danger” category on the Heat Index scale — a category that was not observed during 1991–2020.

An IMD special bulletin on September 20, 2024, cited in the study, recorded a maximum temperature of 38°C with 67% relative humidity in Guwahati. The resulting apparent temperature crossed 60°C, placing conditions in the Extreme Danger zone.

For people working outdoors, the implications are immediate: heat exhaustion, dehydration and reduced work efficiency. The study specifically warns that farmers and agricultural labourers are vulnerable to prolonged exposure to hot and humid field conditions.

What it means for farms

The researchers point to a chain reaction: heat can increase transpiration and moisture loss, leading to wilting; high temperatures can interfere with flowering and pollination; humidity can favour fungal diseases; and warmer conditions can encourage some pest populations.

The study recommends shifting irrigation to early morning or late evening, using mulch to conserve moisture, introducing shade crops or trees where feasible, and stepping up pest and disease surveillance. Farmers and agricultural workers are also advised to avoid prolonged direct exposure during peak heat.

The larger message from the study is clear: Guwahati’s climate challenge is no longer simply about how hot the city gets. It is about heat, humidity and changing rainfall patterns combining to make the monsoon itself increasingly stressful for people and agriculture.