IMD forecasts cooler days, warmer nights and more heatwave spells in parts of India this May

The India Meteorological Department has forecast an unusual weather pattern for May 2026, with much of the country expected to see relatively cooler daytime temperatures, warmer-than-normal nights and above-normal heatwave activity in several regions.

The monthly outlook points to increased pre-monsoon rainfall across large parts of India, which could bring daytime relief but also trap heat overnight due to cloud cover.

Heatwave warning for key regions

The IMD has warned of above-normal heatwave days across:

• Foothill states of the Himalayas, including Punjab, Haryana, Uttarakhand and northern Uttar Pradesh
• Northeast Bihar
• Eastern coastal states such as Odisha, Andhra Pradesh and Tamil Nadu
• Western states including Gujarat and Maharashtra

Heatwave days in these areas may exceed the seasonal norm by one to four days.

Cooler days, warmer nights

Despite heatwave concerns, maximum temperatures across most of India are expected to remain normal to below normal.

Exceptions include parts of southern peninsular India, the Northeast and northwest India, where daytime temperatures could remain above average.

At the same time, minimum nighttime temperatures are likely to stay above normal in most regions.

According to IMD Director General Mrutyunjay Mohapatra, this is largely due to increased cloud cover linked to above-normal rainfall forecasts.

Clouds prevent heat from escaping after sunset, keeping nights warmer.

El Niño concern for monsoon

The IMD has also flagged a growing possibility of strong El Niño development during the monsoon season.

El Niño, which involves warming in the tropical Pacific Ocean, is often associated with weaker monsoon rainfall in India and can significantly affect agriculture.

The agency said the transition from neutral to positive El Niño conditions could influence both heatwave frequency and rainfall distribution in the coming months.

April offered warning signs

IMD data shows April 2026 already reflected intensifying weather extremes.

The month recorded 25 heatwave days across 10 meteorological subdivisions.

The highest number was recorded in eastern Uttar Pradesh and Himachal Pradesh, with four heatwave days each.

Southern peninsular India logged its seventh hottest and driest April since 1901, while northwest India recorded its fifth hottest and driest April on record.

The department also reported 24 deaths linked to extreme weather events during the month.

The forecast underscores the need for heightened caution, particularly for vulnerable groups such as the elderly, children and those with pre-existing health conditions, who face greater risk during prolonged heat stress.