Study reveals steady increase in thunderstorm and lightning activities in Bengaluru

The study reveals that both thunderstorms and lightning in Bengaluru have shown a significant increasing trend, increasing by 3.41% and 3.3% annually. | Photo credit: File photo

On April 29, Bengaluru received heavy downpour associated with thunderstorms and hail. The intensity was so strong that the Bengaluru city station recorded 78 mm of rainfall in about 30 minutes.

A study conducted by scientists and researchers from the India Meteorological Department (IMD), Bangalore University and Andhra University, published in the Current World Environment Journal, found that heavy rainfall and thunderstorms like those that occurred on April 29 were not an isolated but recurring incident.

The study “Thunderstorms and their impact on meteorology and atmospheric composition in the southern peninsula” revealed that Bengaluru is experiencing a significant, statistically verified increase in both thunderstorm and lightning activity.

Using a 13-year data set spanning 2011 to 2023, researchers led by IMD Scientist CS Patil, who is the lead author of the study, found that Bengaluru sees an average of 41 storm days and 157 lightning strikes every year.

Growing trend

The study revealed that both thunderstorms and lightning in Bengaluru showed a significant increasing trend, increasing by 3.41% and 3.3% annually.

She further stated that Bengaluru’s localized data reveals a unique regional microclimate trajectory, as over a 13-year window, the city experienced a steady increase in cumulative rainfall (growing by 1.44 mm per year), relative humidity (growing by 0.74% per year), while local surface temperatures showed a slight decrease of 0.06 °C per year.

According to the study, the combination of high local heat during daylight hours and a heavy supply of moisture from moving monsoon systems creates the perfect thermodynamic recipe for triggering strong storm convection.

“Because heat and moisture are the basic building blocks for thunderstorm development, the likelihood of stronger localized thunderstorms is expected to increase in the coming years,” the researchers said.

When he strikes

They also mapped exactly when thunderstorms and lightning struck the city. “Thunderstorms follow a sharp unimodal curve daily: they are incredibly rare during the morning and mid-morning hours, begin to escalate rapidly after 3:00 p.m. due to diurnal solar heating of the Earth’s surface, and reach their absolute peak in the late evening between 7:00 p.m. and 9:00 p.m.,” they said.

The study further revealed that on an annual scale the city experiences a pattern with two peaks. “The first and largest peak occurs during the pre-monsoon month of May, with an average of 12 storm days, caused by intense thermal instability and ocean depressions. A secondary, weaker peak occurs during the post-monsoon transition in September and October as the monsoon trough recedes south,” the researchers said.

Published – 21 May 2026 21:58 IST