The India Meteorological Department (IMD) has forecast a notably cooler and wetter start to December for India's tech capital. The city of Bengaluru is bracing for significantly lower-than-normal temperatures and light rainfall throughout the first week of the month, a direct impact of Cyclone Ditwah along the Tamil Nadu coast.
IMD's Detailed Forecast for the Week
In its bulletin issued on Monday, December 1, 2025, the weather office predicted generally cloudy skies until Tuesday with a likelihood of moderate rain. Residents can also expect mist during the early morning hours in some localities. The temperature range is set to be unusually low for the season.
The maximum temperature is likely to hover around 21 degrees Celsius, while the minimum is expected to be near 18 degrees Celsius. A marginal rise to around 22 degrees Celsius is anticipated by Wednesday, but conditions will remain cool overall.
How Far Below Normal Are the Temperatures?
The current weather pattern represents a sharp departure from Bengaluru's typical December climate. The predicted maximum of 21°C is nearly six degrees below the normal average for this time of year. Similarly, the minimum of 18°C is 1.5 degrees below the seasonal norm.
This cooling trend began around November 27, when cyclonic conditions developed over the Bay of Bengal. Since then, the city's maximum temperature has consistently registered 2 to 6 degrees below normal levels. Data from Sunday showed a maximum of 21.6°C (5.8° below normal) and a minimum of 18.4°C (1.2° below normal).
For context, the mean maximum temperature in Bengaluru for December over the past 15 years stands at 26.9 degrees Celsius, with an average minimum of 16.4 degrees Celsius.
Rain, Wind, and the Cyclone's Influence
Alongside the chill, the IMD has forecast light rain accompanied by sustained winds of 30-40 kmph for Monday. Light to moderate rain is expected to persist for the rest of the week. This unusual weather for early December is attributed to Cyclone Ditwah, which moved parallel to the Indian coastline.
The cyclone, which caused severe damage and over 300 fatalities in Sri Lanka, ultimately weakened into a deep depression without making landfall in India. However, its peripheral influence is driving the current weather activity over Bengaluru and surrounding regions.
While the current temperatures feel notably low, historical IMD records show Bengaluru has experienced colder spells. The all-time lowest minimum temperature recorded was 7.8 degrees Celsius on January 13, 1884. In more recent history, the coldest December night in the last 15 years was 12.8°C on December 24, 2011.
