If you have been feeling that Bengaluru has been witnessing too many thunderstorms lately, scientists say you are absolutely right. A new 13-year study found that thunderstorm and lightning activity over the city has been steadily rising, pointing to a major shift in local climate patterns.
The study, conducted between 2011 and 2023 using ground observations and satellite data around Kempegowda International Airport and Bengaluru, found that thunderstorms in the city are increasing by 3.41% every year, while lightning activity is rising by 3.3% annually.
The research was carried out jointly by scientists from the India Meteorological Department, Bangalore University and Andhra University, and has now been published in the journal Current World Environment. According to the findings, Bengaluru currently records an average of 41 thunderstorm days and nearly 157 lightning events every year.
Researchers say the increase is linked to rising atmospheric moisture, changing monsoon patterns, urban heat buildup and growing air pollution over the city.
Peak hours
The study found that thunderstorms in Bengaluru are most commonly seen between 7 pm and 9 pm, with many weather events continuing until 3 am. Very few thunderstorms occur between early morning and noon unless triggered by cyclonic conditions. Scientists observed that Bengaluru experiences two major thunderstorm peaks every year: The first during April and May and the second during September and October. The southwest and northeast monsoons bring large amounts of moisture into the atmosphere, creating ideal conditions for thunderstorm formation over the city.
Researchers also pointed out that Bengaluru’s weather itself has undergone noticeable changes during the last decade. Annual rainfall has increased by an average of 1.44 mm every year, while relative humidity has gone up by 0.74% annually. Atmospheric pressure too has shown a steady rise. Interestingly, average surface temperatures and wind speeds have slightly reduced over the same period.
Pollution link
The study further highlights how air pollution and thunderstorms are now closely interacting over Bengaluru. Scientists observed increasing levels of atmospheric pollutants such as nitrogen dioxide, ozone and aerosols. Ozone levels, in particular, were found to rise sharply during high-temperature conditions due to faster chemical reactions in the atmosphere.
Thunderstorms were also found to directly impact pollution levels across the city. PM2.5 concentrations gradually reduce once thunderstorms begin because rain helps wash pollutants out of the atmosphere.
Ozone levels react within an hour of a thunderstorm, while nitrogen dioxide levels change after nearly two-and-a-half hours due to shifting wind patterns during storm activity.
Experts warn that with increasing humidity, pollution and atmospheric instability, Bengaluru could witness even more intense thunderstorms, lightning strikes and sudden evening downpours in the coming years. The research was carried out by meteorologist Chanabasanagouda Sanganagouda Patil along with researchers Shaik Darga Saheb, Gunta Paparao and Kamsali Nagaraja. The findings come at a time when residents across the city have repeatedly complained of stronger winds, sudden rain bursts and frequent lightning activity during recent pre-monsoon weeks.
