Key Terms & Concepts — UPSC Mains
Cloudburst
"A sudden, extremely intense burst of rainfall over a small area, defined by the IMD as more than 100 mm of rain in one hour"
A cloudburst is a sudden, very heavy downpour concentrated over a small area, officially defined by the India Meteorological Department as rainfall exceeding 100 mm per hour over an area of about 20 to 30 square kilometres. Cloudbursts occur when warm, moisture-laden air is forced rapidly upward, often over steep mountain terrain, causing towering clouds to release their water almost all at once. In the Himalayas and Western Ghats they frequently trigger flash floods, landslides and debris flows that devastate hill communities, especially during the monsoon.
Relevant for GS1 (geography, weather systems, Himalayan hazards) and GS3 (disaster management, climate change). Warming is increasing the frequency of intense, localised rainfall, and cloudbursts have driven repeated disasters in Uttarakhand, Himachal Pradesh and Jammu and Kashmir. Recurrent 2025 and 2026 monsoon-season events keep cloudbursts central to India's disaster-preparedness debate.
- 1 IMD defines a cloudburst as more than 100 mm of rainfall in one hour over about 20 to 30 sq km
- 2 Caused by rapid uplift of moist air, intensified by steep mountainous (orographic) terrain
- 3 Commonly trigger flash floods, landslides and debris flows in hilly regions
- 4 [object Object]
- 5 Very hard to forecast because they are highly localised and short-lived
- 6 Climate change is raising the frequency of extreme short-duration rainfall events
- 7 Mitigation includes doppler radar networks, the C-FLOOD warning system and slope-stabilisation
Cloudbursts triggered deadly flash floods in the Himalayan states again during the 2025 monsoon, including the Dharali and Harsil disaster in Uttarakhand, keeping early-warning radar expansion a priority into 2026.
