September is one of the warmer months of the year in West Champaran, with average highs near 31.5°C and lows around 24.6°C (mean 28.1°C). It is a relatively wet time of year, averaging 176 mm of rainfall and 82% relative humidity across the period.
September is one of the warmer months of the year in West Champaran. Across 45 years of records, the warmest September in West Champaran was 1983 — when the month averaged 30.2°C — while the coldest was 1984 at 26.5°C. Typical September days reach 31.5°C with nights near 24.6°C. The long-term September temperature trend is broadly flat.
September is a relatively wet time of year in West Champaran, averaging 176 mm of rainfall. The wettest September on record was 2012 with 352 mm, while the driest was 1983 at 51 mm.
Relative humidity in West Champaran during September averages 82%. The most humid September was 2021 at 89%, and the least humid was 2002 at 67%.
September receives about 4.6 kWh/m²/day of solar energy in West Champaran. The sunniest September was 1996 at 5.4 kWh/m²/day, and the cloudiest was 2019 at 3.7.
Average wind speed in West Champaran during September is 1.7 m/s. The windiest September was 1983 at 2.4 m/s, while the calmest were 2001, 2004 and 2016 at 1.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 28.0°C | 28.3°C | 28.0°C | 27.8°C | 28.2°C | +0.2°C |
| Avg High | 31.6°C | 32.2°C | 31.5°C | 31.1°C | 31.1°C | -0.5°C |
| Avg Low | 24.3°C | 24.4°C | 24.4°C | 24.6°C | 25.3°C | +1°C |
| Avg Rain | 156 mm | 121 mm | 162 mm | 223 mm | 240 mm | +84 mm |
September temperatures in West Champaran have risen by about 0.5°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 17.3°C (1994) to a record high of 38°C (2002).
Rainfall in September is a relatively wet time of year, averaging 176 mm, with a wettest year of 352 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.2°C per decade while lows rose 0.2°C per decade, narrowing the gap between day and night.
A good time to visit West Champaran
September is a good time to visit West Champaran, with days averaging 31.5°C and nights around 24.6°C (mean 28.1°C, warmer than West Champaran's yearly average) and higher rainfall. November and February are marginally more temperate, but September still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 31.1°C | 28.2°C | 25.3°C | 33.3°C | 23.9°C | 251 mm | 87% | 1.6 m/s | 4.5 |
| 2024 | 31.4°C | 28.5°C | 25.6°C | 34.9°C | 22.7°C | 308 mm | 87% | 1.8 m/s | 4.4 |
| 2023 | 31.4°C | 28.4°C | 25.4°C | 33.2°C | 24.0°C | 118 mm | 87% | 1.8 m/s | 4.3 |
| 2022 | 30.7°C | 27.8°C | 24.9°C | 32.4°C | 22.8°C | 259 mm | 87% | 1.6 m/s | 3.8 |
| 2021 | 30.6°C | 28.0°C | 25.4°C | 32.2°C | 24.4°C | 191 mm | 89% | 1.8 m/s | 4.5 |
| 2020 | 31.1°C | 28.1°C | 25.0°C | 33.8°C | 22.2°C | 311 mm | 86% | 1.4 m/s | 4 |
| 2019 | 30.3°C | 27.6°C | 24.9°C | 33.5°C | 21.2°C | 297 mm | 87% | 2 m/s | 3.7 |
| 2018 | 31.9°C | 28.3°C | 24.7°C | 33.3°C | 22.7°C | 119 mm | 84% | 1.9 m/s | 4.8 |
| 2017 | 31.6°C | 28.4°C | 25.3°C | 32.9°C | 24.2°C | 157 mm | 86% | 1.5 m/s | 4.8 |
| 2016 | 30.9°C | 28.0°C | 25.1°C | 33.1°C | 23.3°C | 274 mm | 86% | 1.3 m/s | 3.8 |
| 2015 | 31.6°C | 27.8°C | 24.1°C | 33.6°C | 19.4°C | 123 mm | 81% | 1.4 m/s | 5.1 |
| 2014 | 30.9°C | 27.5°C | 24.1°C | 33.5°C | 20.8°C | 226 mm | 85% | 1.5 m/s | 4.6 |
| 2013 | 31.4°C | 28.0°C | 24.6°C | 33.1°C | 22.9°C | 222 mm | 84% | 1.4 m/s | 4.9 |
| 2012 🌧️ | 31.0°C | 27.4°C | 23.8°C | 33.0°C | 21.6°C | 352 mm | 84% | 1.4 m/s | 4.6 |
| 2011 | 30.9°C | 27.8°C | 24.6°C | 32.9°C | 22.8°C | 213 mm | 86% | 1.7 m/s | 4.6 |
| 2010 | 30.6°C | 27.4°C | 24.3°C | 32.6°C | 21.9°C | 247 mm | 87% | 1.9 m/s | 4.4 |
| 2009 | 31.5°C | 28.0°C | 24.5°C | 33.7°C | 23.2°C | 93 mm | 84% | 1.5 m/s | 5.1 |
| 2008 | 30.3°C | 27.2°C | 24.1°C | 32.3°C | 21.6°C | 234 mm | 87% | 1.5 m/s | 5.1 |
| 2007 | 30.2°C | 27.2°C | 24.2°C | 32.4°C | 21.6°C | 282 mm | 86% | 1.8 m/s | 4.3 |
| 2006 | 30.7°C | 27.4°C | 24.1°C | 33.0°C | 22.4°C | 219 mm | 85% | 1.6 m/s | 4.7 |
| 2005 | 31.1°C | 27.9°C | 24.7°C | 33.2°C | 23.2°C | 92 mm | 85% | 1.6 m/s | 4.9 |
| 2004 | 31.2°C | 27.7°C | 24.1°C | 33.3°C | 22.3°C | 131 mm | 81% | 1.3 m/s | 4.8 |
| 2003 | 33.6°C | 29.6°C | 25.7°C | 36.3°C | 23.2°C | 93 mm | 73% | 2.1 m/s | 4.3 |
| 2002 | 34.8°C | 29.9°C | 25.0°C | 38.0°C | 23.8°C | 92 mm | 67% | 2.2 m/s | 4.6 |
| 2001 | 31.1°C | 27.6°C | 24.1°C | 32.6°C | 21.8°C | 203 mm | 83% | 1.3 m/s | 4.3 |
| 2000 | 30.7°C | 27.3°C | 24.0°C | 32.6°C | 20.7°C | 184 mm | 84% | 1.9 m/s | 4.2 |
| 1999 | 33.0°C | 29.0°C | 25.0°C | 35.4°C | 23.4°C | 65 mm | 75% | 2.2 m/s | 4.9 |
| 1998 | 31.5°C | 28.0°C | 24.5°C | 33.3°C | 23.2°C | 137 mm | 84% | 1.9 m/s | 5.1 |
| 1997 | 32.7°C | 28.6°C | 24.4°C | 34.7°C | 21.4°C | 91 mm | 77% | 1.7 m/s | 4.5 |
| 1996 | 31.8°C | 28.2°C | 24.7°C | 33.3°C | 23.0°C | 103 mm | 82% | 1.5 m/s | 5.4 |
| 1995 | 31.9°C | 28.2°C | 24.5°C | 34.3°C | 22.6°C | 106 mm | 80% | 2 m/s | 5 |
| 1994 | 32.3°C | 28.0°C | 23.6°C | 37.4°C | 17.3°C | 175 mm | 76% | 1.9 m/s | 4.9 |
| 1993 | 31.4°C | 27.8°C | 24.1°C | 34.9°C | 22.5°C | 154 mm | 80% | 2.2 m/s | 4.6 |
| 1992 | 34.3°C | 29.4°C | 24.5°C | 36.1°C | 21.5°C | 96 mm | 70% | 1.9 m/s | 5 |
| 1991 | 32.2°C | 28.3°C | 24.4°C | 33.4°C | 22.0°C | 162 mm | 80% | 1.5 m/s | 4.4 |
| 1990 | 31.0°C | 27.7°C | 24.5°C | 33.5°C | 22.6°C | 126 mm | 85% | 1.8 m/s | 4.3 |
| 1989 | 33.6°C | 29.4°C | 25.3°C | 36.9°C | 22.9°C | 94 mm | 73% | 2 m/s | 4.4 |
| 1988 | 31.5°C | 28.1°C | 24.6°C | 33.4°C | 22.7°C | 99 mm | 85% | 1.8 m/s | 4.9 |
| 1987 | 30.5°C | 27.4°C | 24.4°C | 32.9°C | 21.8°C | 289 mm | 86% | 1.5 m/s | 4.3 |
| 1986 | 32.7°C | 28.2°C | 23.7°C | 35.3°C | 21.2°C | 58 mm | 73% | 2.3 m/s | 5 |
| 1985 | 30.0°C | 27.1°C | 24.2°C | 32.7°C | 22.0°C | 252 mm | 87% | 1.7 m/s | 4.4 |
| 1984 ❄️ | 30.0°C | 26.5°C | 23.1°C | 31.5°C | 20.0°C | 238 mm | 85% | 1.9 m/s | 4.8 |
| 1983 🔥 | 34.6°C | 30.2°C | 25.9°C | 37.5°C | 24.7°C | 51 mm | 69% | 2.4 m/s | — |
| 1982 | 31.5°C | 27.6°C | 23.6°C | 35.5°C | 19.4°C | 161 mm | 81% | 1.7 m/s | — |
| 1981 | 30.4°C | 27.3°C | 24.3°C | 33.6°C | 22.7°C | 158 mm | 86% | 1.8 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 31.5°C with lows near 24.6°C (mean 28.1°C), based on 45 years of NASA POWER data.
September averages 176 mm of rainfall in West Champaran, a relatively wet time of year. The wettest on record was 352 mm in 2012.
The hottest September reached 38°C in 2002. The coldest dipped to 17.3°C in 1994.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.5°C — but days and nights have moved in opposite directions. Overnight lows rose from 24.2°C to 25.3°C while daytime highs eased from 31.3°C to 31°C, narrowing the gap between day and night.
September is one of the warmer months of the year in West Champaran and a relatively wet time of year, so plan for around 31.5°C daytime highs and 24.6°C at night.
Not quite — September is the 7th coolest month in West Champaran, averaging 28.1°C.
For September in West Champaran, pack light, breathable clothing and sun protection, with typical highs of 31.5°C and lows of 24.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 82% — quite humid.
Average wind speed in September is 1.7 m/s. The windiest September on record averaged 2.4 m/s (1983).
The wettest September on record was 2012 with 352 mm. On average, September sees 176 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in West Champaran behaves each September, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for September specifically, along with year-by-year records and how the month has changed over the decades.
