Arunachal Pradesh Weather Forecast & Climate Summary
Arunachal Pradesh is India's most mountainous northeastern state, spanning the entire eastern Himalaya from steamy, monsoon-drenched foothills near Assam to cold, dry, trans-Himalayan valleys near the Tibetan border — often within the same district. For live interactive rainfall, wind and satellite maps over Arunachal Pradesh, open VayuMet.
Geography & Seasonal Cycle
Elevation rises from around 100 m in the southern foothills bordering Assam to over 7,000 m near the tri-junction of the India-China-Myanmar border region. The southern and central hills catch the full force of monsoon moisture moving up from the Bay of Bengal, while high trans-Himalayan valleys such as Tawang and upper Subansiri lie in the rain shadow of the higher ranges, producing a much colder, drier, near-desert climate despite being part of the same state.
The monsoon (June-September) dominates the southern and central foothills with extremely heavy, sustained rainfall. Winter (December-February) brings cold conditions statewide and snowfall to the higher Himalayan valleys, often linked to western disturbances reaching this far east. Pre-monsoon (March-May) is transitional, with rising heat in the lower foothills and lingering cold at altitude.
Weather Systems by Season
Moisture from the Bay of Bengal is forced upward against the eastern Himalaya's foothills, producing some of the heaviest sustained rainfall totals in the country.
Western disturbances occasionally reach this far east and combine with the Himalaya's own moisture to bring snowfall to high-altitude areas such as Tawang and Bomdila.
The combination of very steep terrain and very heavy rainfall makes flash floods and landslides a routine monsoon-season hazard, frequently disrupting the state's already limited road network.
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.
Seasonal Weather Data
The table below is a state-wide average across Arunachal Pradesh's 25 districts, built from IMD's real 1991-2020 gridded rainfall/temperature normals and 1951-2025 daily archives (not a forecast). The wet southern foothills and the dry, cold trans-Himalayan valleys 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 | 47.5 | 20.3 | 17.9 / 5.2 | 19.9 / 3.0 | 22.8·36.2·0.0 |
| Pre-Monsoon (Summer) Mar–May | 457.2 | 60.7 | 23.0 / 12.6 | 26.6 / 7.6 | 8.2·76.9·6.9 |
| Monsoon (SW) Jun–Sep | 1396.3 | 100.8 | 26.8 / 18.7 | 28.2 / 16.8 | 4.2·104.8·13.0 |
| Post-Monsoon Oct–Dec | 120.7 | 24.7 | 21.8 / 9.2 | 26.2 / 3.0 | 34.2·56.9·0.9 |
State figures are a simple average across 25 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).
Recorded Extremes (IMD 1951–2025 Gridded Data)
- Highest maximum temperature recorded (Changlang): 38.5°C — 25 May 2024
- Lowest minimum temperature recorded (Changlang): 4.7°C — 13 Jan 1989
- Highest 24-hour rainfall recorded (Lower Subansiri): 632 mm — 19 Jul 1980
- Highest monthly rainfall recorded (Lower Subansiri): 2426 mm — Jul 1980
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.
Risk Profile
Monsoon (Jun-Sep). Extreme relief combined with very heavy rainfall makes this the state's most frequent and disruptive weather-linked hazard.
Monsoon / long-term. High-Himalayan glacial lakes in the state's north are an emerging hazard of growing concern in broader Himalayan climate risk assessments, alongside the more immediate monsoon flood risk.
Winter (Dec-Feb). High-altitude districts such as Tawang face severe winter cold and periodic heavy snowfall, disrupting road access.
Monsoon (Jun-Sep). The state's mountainous terrain means landslide-triggered road closures are a routine, significant consequence of the monsoon season.
Arunachal Pradesh Weather Highlights
- Arunachal Pradesh spans one of the most extreme rainfall-with-altitude gradients in India, from some of the country's wettest foothills to genuinely cold, dry, trans-Himalayan valleys like Tawang.
- Its extreme relief and heavy monsoon rainfall combine to make landslide-triggered road disruption a routine, expected part of the monsoon season rather than an occasional event.
- The state's high-Himalayan north sits within the same broader glacial-hazard zone as Sikkim and Uttarakhand, an area of increasing scientific and disaster-management attention.
All 25 Districts
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).