Karnataka spans one of India's steepest rainfall gradients within a single state: a narrow, extremely wet Arabian Sea coast and Western Ghats belt on one side, and a much drier Deccan plateau interior on the other, with the northeast monsoon adding a smaller but meaningful third contribution in the south. For live interactive rainfall, wind and satellite maps over Karnataka, open VayuMet.
The Karavali coastal strip faces the Arabian Sea directly. Immediately inland, the Western Ghats (locally the Malnad region) rise steeply and catch enormous amounts of monsoon rainfall on their windward slopes — among the highest totals anywhere in India. East of the Ghats crest, the Deccan plateau (Bayaluseeme) drops sharply in rainfall, especially in the north, producing a semi-arid interior that contrasts starkly with the coast only a few hundred kilometres away.
Winter (December-February) is mild and dry across most of the state. Summer (March-May) is hot, most severe in the north interior around Kalaburagi and Bidar. The southwest monsoon (June-September) dominates the coast and Ghats with extreme totals while the interior plateau receives comparatively little. The northeast monsoon (October-December) then adds a secondary, smaller rainy season, mainly benefiting the south interior including Bengaluru.
The Western Ghats force the Arabian Sea monsoon current upward, producing some of the highest rainfall totals in India on the windward (coast-facing) slopes — the Agumbe-Hulikal belt is regularly cited among the wettest locations in the country.
Immediately east of the Ghats crest, rainfall drops off sharply, leaving north Karnataka's Bayaluseeme plateau semi-arid even during an otherwise active monsoon season.
Unlike much of peninsular India's interior, south Karnataka (including Bengaluru) receives a genuine secondary rainy season from the retreating northeast monsoon.
Occasionally, the remnants of an Arabian Sea cyclone or depression add unusually heavy rain to the coast outside the typical monsoon pattern.
Frequencies cited from published IMD/IITM climatology where a source is named inline; day-count figures in the table below are computed directly from the 1951–2025 IMD daily archive.
The table below is a state-wide average across Karnataka's 31 districts, built from IMD's real 1991-2020 gridded rainfall/temperature normals and 1951-2025 daily archives (not a forecast). The coast/Ghats and the north interior sit at opposite extremes of this average — use the district climatology tool linked below for any single district's own figures.
| Season | Rainfall (mm) | Rain days | Mean Max / Min (°C) | Typical Hottest / Coldest (°C) | Sky (Sunny·Partly·Overcast days) |
|---|---|---|---|---|---|
| Winter Jan–Feb | 5.4 | 1.5 | 30.4 / 17.3 | 33.0 / 15.9 | 6.3·50.5·2.2 |
| Pre-Monsoon (Summer) Mar–May | 133.0 | 25.0 | 34.7 / 22.3 | 36.0 / 19.3 | 1.8·74.9·15.3 |
| Monsoon (SW) Jun–Sep | 807.3 | 82.0 | 29.1 / 21.4 | 33.3 / 20.7 | 0.0·40.4·81.6 |
| Post-Monsoon Oct–Dec | 177.6 | 25.9 | 29.0 / 18.7 | 30.1 / 15.7 | 5.9·77.4·8.7 |
State figures are a simple average across 31 member districts (IMD Pune 1991–2020 normal; day-count and sky figures from real 1951–2025 daily archives — see District Climatology tool for any single district's own numbers, which can differ substantially from this state average).
Computed directly from the real IMD 1951–2025 daily gridded archive — not a forecast, and not the same as a single-station record. IMD's gridded temperature is 1°×1° (~111 km/cell) and rainfall is 0.25°×0.25° (~25 km/cell); both are spatial analyses of many station observations; a famous single-station record (e.g. a specific town's all-time hottest day) will typically read higher than the grid-cell value shown here, since one station reading isn't smoothed over a ~25–111 km box. "Place" is the nearest district to the grid cell where the extreme occurred, not necessarily the exact spot.
Structural, north interior. North Karnataka's plateau districts are chronically water-stressed, with agriculture highly exposed to monsoon variability.
Monsoon (Jun-Sep). Coastal and Ghats districts, and the Krishna and Cauvery basins, are prone to flooding in an active monsoon; the 2018 Kodagu floods were a notable recent example.
Monsoon (Jun-Sep). Kodagu and other Western Ghats districts face landslide risk on saturated, steep terrain during sustained heavy rain.
Summer (Mar-May). The Kalaburagi-Bidar belt in north Karnataka sees the state's most intense pre-monsoon heat.
Click a district on the District Climatology tool or search it on the 10-day forecast page for its own normals — the grid below is the full current list (India's Local Government Directory codes, cross-checked against the latest state reorganisation).