Climate averages 1991–2020
Siwān weather
in December.
A warm, very dry month: the 11th warmest and the 2nd driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
December is a warm month in Siwān: daytime highs average 23.7°C and nights cool to about 11.8°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 7.6 mm of rain on fewer than one day, which makes December a very dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 10 h 32 min on an average December day.
The nearest other city in this atlas is Chāpra (63 km away). In December its highs average 23.6°C, about as warm as Siwān, with 7.6 mm of rain.
Among the 692 cities listed in India, Siwān ranks joint 463rd of 692 for the warmest December highs and joint 317th of 692 for the driest December (rainfall, lowest first). The mean December high of those 692 cities is 25.6°C; Siwān is 1.9°C cooler than that mean.
From December to January, average highs fall by 1.9°C to 21.8°C, and monthly rainfall rises from 7.6 mm to 16 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Siwān climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 21.8°C10.3°C | 10.3°C | 16 | 2.2 | 10.711 h |
| February | 25.7°C13.2°C | 13.2°C | 17 | 2.4 | 11.311 h |
| March | 32.0°C18.2°C | 18.2°C | 12 | 2.1 | 12.012 h |
| April | 37.1°C23.3°C | 23.3°C | 10 | 2.5 | 12.813 h |
| May | 37.6°C26.1°C | 26.1°C | 29 | 5.2 | 13.413 h |
| June | 35.6°C27.0°C | 27.0°C | 180 | 15.5 | 13.814 h |
| July | 31.9°C26.3°C | 26.3°C | 329 | 26.0 | 13.614 h |
| August | 31.5°C26.0°C | 26.0°C | 294 | 26.6 | 13.113 h |
| September | 30.9°C25.0°C | 25.0°C | 205 | 20.5 | 12.312 h |
| October | 30.2°C21.3°C | 21.3°C | 37 | 4.3 | 11.612 h |
| November | 27.8°C16.0°C | 16.0°C | 4.5 | 0.4 | 10.911 h |
| December, selected | 23.7°C11.8°C | 11.8°C | 7.6 | 0.7 | 10.511 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Chāpra in DecemberIndia · 63 kmHigh 23.6°C · Low 12.4°C · 7.6 mm rain
- Deoria in DecemberIndia · 65 kmHigh 23.5°C · Low 11.5°C · 7.9 mm rain
- Bettiah in DecemberIndia · 66 kmHigh 23.6°C · Low 11.9°C · 8.4 mm rain
- Mothīhāri in DecemberIndia · 73 kmHigh 23.8°C · Low 12.0°C · 7.8 mm rain
- Kushinagar in DecemberIndia · 74 kmHigh 23.5°C · Low 11.5°C · 8.9 mm rain
- Arrah in DecemberIndia · 80 kmHigh 23.7°C · Low 12.2°C · 7.0 mm rain
- Buxar in DecemberIndia · 81 kmHigh 23.6°C · Low 11.6°C · 6.9 mm rain
- Mau in DecemberIndia · 85 kmHigh 23.6°C · Low 11.3°C · 6.7 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Siwān) is explained once on the Siwān year overview and on the Sources, method and limits page.