4 min readPuneAug 7, 2026 11:42 AM IST
First published on: Aug 7, 2026 at 11:42 AM IST
While declaring an orange alert for heavy to isolated very heavy rainfall in the Ghats of Pune on August 5 and 6, the India Meteorological Department (IMD) said that Pune city would not be similarly impacted. The latter would receive 2.5-35.5 mm of very light to light rainfall on both days.
True to the forecast, several areas in the Ghats were pelted with heavy rain. Like Tamhini, one of the country’s wettest places, which recorded 102 mm of rain between the mornings of August 5 and 6. Yet, during these 24 hours, Pune’s main weather office, Shivajinagar, received only 2.4 mm of rain.
The distance by road between Pune and Tamhini is around 60 km, which can be covered by car in an hour and a half. Yet, the average rainfall in Tamhini is around 7,000 mm annually, while the Pune plains receive between 720 mm and 1,000 mm average annual rainfall over 49 rainy days. Bhira, Koyna, and other Ghat stations also routinely report rainfall several times higher than Pune.
Why is there heavier rain in the Ghats than in Pune?
The southwest monsoon reaches Maharashtra after travelling across the Arabian Sea, carrying large quantities of moisture. As these moisture-laden westerly winds move eastwards, they encounter the Western Ghats, which act like a giant wall.
When the moist air strikes the mountain barrier, it empties its rain in the Ghat areas. Tamhini is located on the windward side of the Western Ghats, the side directly exposed to the incoming Arabian Sea monsoon winds. The same is true for Bhira, Lonavala, Khandala and parts of Mulshi.
“Pune, lying east of the Ghats, is on the leeward side of the mountain range. After emptying its rain in the Ghats, the winds travel to Pune carrying only remnants of moisture. It is harder for clouds to form, hence rainfall is reduced significantly. We call this the rain shadow effect,” says Dr Anupam Kashyapi, former head of the weather forecasting division of the India Meteorological Department.
He adds that a similar phenomenon can be seen in the Himalayan region, where the foothills receive more rain than places in the plains or on the leeward side.
Do any weather systems carry rain to Pune before the Ghats?
If an upper-air cyclonic circulation or any other weather system, like a low, well-marked low or depression, has formed over the Bay of Bengal and is travelling westward or west-northwestward, the concept of windward and leeward sides is unlikely. The system passes over the plains before hitting the Ghats. But, even then, the hills receive more rainfall than the Pune plains. “The system hits the hills of the Ghat region, causing heavier precipitation there,” says Kashyapi.
He says that the role played by orography—the study of mountains, hills, and terrain—is far more significant than the distance between two locations. “Pune receives one-fourth the amount of rain Mumbai does. This is not only because Mumbai is on the windward side, but it has hills and adjacent water bodies. The moving air hits these hills, rises up, cools and condenses and then starts falling. This leads to rain on the windward side of the hill. The plains of Pune are, comparatively, flat,” says Kashyapi. He adds that the further the monsoon wind travels from the Ghat areas, the more the rainfall decreases.
Is the rain-shadow impact absolute in Pune?
When monsoon depressions, upper-air cyclonic circulations, offshore troughs, or other weather systems become strong, they carry large quantities of moisture inland. In these cases, Pune experiences episodes of heavy and very heavy rainfall. There might be record-breaking rain, even if Pune does not match the Ghats in volume or quantity.
After emptying its rain in the Western Ghats, the winds travel to Pune with only remnants of moisture. This impacts the rainfall in Pune. (File Photo) 
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