Karnataka Summer Forecast: IMD Predicts Intense Heatwaves and Rising Temperatures for Bengaluru

IMD’s latest summer outlook has signalled a harsher-than-usual March–May for Karnataka, with Bengaluru also in the line of fire. The department expects above-normal maximum temperatures across the state, short heatwave spells and warmer nights, warning that conditions could start tightening from early March itself, after an already warm February, if current atmospheric patterns hold through the pre-monsoon months.

The seasonal forecast, shared during a recent IMD review on heatwave preparedness, puts Karnataka among regions with a high probability of abnormal heat. Officials say there is a 65–75 per cent chance of above-normal maximum temperatures over coastal Karnataka, with interior districts, including Bengaluru Urban, also expected to record higher-than-average daytime and night-time temperatures this summer.

IMD forecast: Hotter March–May for Karnataka and Bengaluru

According to IMD, Karnataka is likely to see repeated 3–6 day heatwave spells between March and May, punctuated by short-lived breaks in temperature. While the harshest conditions are expected over north-interior and coastal districts, the outlook for south-interior Karnataka indicates persistent above-normal heat, with Bengaluru moving away from its historically moderate pre-monsoon profile.

For Bengaluru, IMD climatological data show an average maximum of about 33–34°C in April and 33°C in May. Recent years have departed sharply from this baseline, with many days exceeding 37°C and crossing into heatwave territory by local thresholds, suggesting that a similar or worse pattern this year would mean more frequent hot afternoons and warmer, uncomfortable evenings across the city’s core and suburbs.

Month	Climatological max (°C)	Recent peak (year)	Recent peak (°C)
March	33.1	2024	≈37
April	34.0	2016	39.2
May	33.3	2024	38.1

These departures are not abstract numbers for Bengaluru residents; last summer offered a preview. In April 2024, the city crossed 37°C on at least fourteen days, briefly touching 38.5°C, the second-highest temperature on record, before May brought a 40-year high of 38.1°C. The IMD categorised such levels as heatwave conditions for a plateau city traditionally known for milder summers.

Why this summer could feel harsher on ground

Meteorologists link the expected March–May heat to lingering ocean–atmosphere anomalies. During the IMD’s heatwave review, experts discussed the ongoing El Niño–Southern Oscillation signal and its interaction with the Indian Ocean Dipole, both of which can suppress rainfall and enhance heating over peninsular India. Reduced pre-monsoon showers often mean hotter afternoons, drier winds and a slower night-time cool-down in cities.

Urban factors are set to magnify the impact in Bengaluru. Researchers and IMD officials have repeatedly pointed to shrinking green cover, dense built-up clusters and expanding paved surfaces, all of which trap heat and create local urban heat islands. During the 2024 summer spike, IMD scientists described the four-degree jump above normal as “alarming”, warning that similar episodes could become more frequent without mitigation.

Heat preparedness: BBMP, health officials and daily life

Against this backdrop, civic and health agencies are being pushed to sharpen their response. The Union health ministry has already urged states to activate heat action plans, and Karnataka health authorities have advised hydration, avoiding peak afternoon exposure and early identification of heatstroke symptoms. City hospitals have been told to keep ORS stocks, cooling facilities and emergency beds ready for sudden surges.

At the city level, BBMP has in previous summers opened shelters, arranged drinking water points and coordinated with ward officials during intense spells. Civil society groups are now urging wider measures, including extending public park hours to offer shade to delivery workers, street vendors and commuters forced to walk during hot hours, an idea already gaining traction in Bengaluru’s southern neighbourhoods.

The implications of a harsher summer will be felt well beyond discomfort. Higher daytime temperatures translate into heavier air-conditioning and cooling loads, pushing up household power bills and straining the grid, while outdoor workers, schoolchildren and the elderly face higher health risks. With IMD signalling a hot March–May window, how swiftly Bengaluru adapts—from shade, water and working hours to medical readiness—will shape how bearable this season ultimately feels.