Climate averages 1991–2020
Biratnagar weather
in September.
A hot, very wet month: the 7th warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Biratnagar: daytime highs average 30.0°C and nights cool to about 24.4°C. By daytime temperature it is the 7th warmest of the 12 months.
Expect about 277 mm of rain on roughly 23 days, which makes September a very wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 20 min on an average September day.
The nearest other city in this atlas is Inaruwa (21 km away). In September its highs average 29.4°C, 0.6°C cooler than Biratnagar, with 277 mm of rain.
Among the 16 cities listed in Nepal, Biratnagar ranks 5th of 16 for the warmest September highs and joint 11th of 16 for the driest September (rainfall, lowest first). The mean September high of those 16 cities is 28.9°C; Biratnagar is 1.1°C warmer than that mean.
From September to October, average highs fall by 0.6°C to 29.4°C, and monthly rainfall falls from 277 mm to 77 mm.
The annual picture
September 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
Biratnagar climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 22.3°C11.1°C | 11.1°C | 8.9 | 1.4 | 10.711 h |
| February | 25.3°C13.5°C | 13.5°C | 12 | 1.7 | 11.211 h |
| March | 31.0°C17.9°C | 17.9°C | 12 | 2.4 | 12.012 h |
| April | 33.9°C22.1°C | 22.1°C | 34 | 6.2 | 12.813 h |
| May | 32.8°C24.2°C | 24.2°C | 118 | 14.9 | 13.413 h |
| June | 31.2°C25.2°C | 25.2°C | 306 | 24.5 | 13.814 h |
| July | 30.4°C25.4°C | 25.4°C | 412 | 29.5 | 13.614 h |
| August | 30.6°C25.4°C | 25.4°C | 346 | 28.5 | 13.113 h |
| September, selected | 30.0°C24.4°C | 24.4°C | 277 | 23.0 | 12.312 h |
| October | 29.4°C21.0°C | 21.0°C | 77 | 6.1 | 11.612 h |
| November | 27.3°C16.1°C | 16.1°C | 3.6 | 0.6 | 10.911 h |
| December | 24.0°C12.4°C | 12.4°C | 3.9 | 0.5 | 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
September in nearby cities
- Inaruwa in SeptemberNepal · 21 kmHigh 29.4°C · Low 24.1°C · 277 mm rain
- Dharān in SeptemberNepal · 40 kmHigh 28.0°C · Low 23.0°C · 276 mm rain
- Arāria in SeptemberIndia · 42 kmHigh 30.5°C · Low 24.6°C · 358 mm rain
- Triyuga in SeptemberNepal · 68 kmHigh 29.4°C · Low 24.1°C · 243 mm rain
- Purnia in SeptemberIndia · 78 kmHigh 30.6°C · Low 24.8°C · 295 mm rain
- Kishanganj in SeptemberIndia · 79 kmHigh 30.4°C · Low 24.7°C · 309 mm rain
- Lahān in SeptemberNepal · 84 kmHigh 29.5°C · Low 24.0°C · 239 mm rain
- Saharsa in SeptemberIndia · 93 kmHigh 30.7°C · Low 24.9°C · 244 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 Biratnagar) is explained once on the Biratnagar year overview and on the Sources, method and limits page.
Inaruwa lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.