September is one of the warmer months of the year in Sirmaur, with average highs near 28.9°C and lows around 20.3°C (mean 24.6°C). It is a relatively wet time of year, averaging 176 mm of rainfall and 75% relative humidity across the period.
September is one of the warmer months of the year in Sirmaur. Across 45 years of records, the warmest September in Sirmaur was 1987 — when the month averaged 27.7°C — while the coldest was 1984 at 23.1°C. Typical September days reach 28.9°C with nights near 20.3°C. The long-term September temperature trend is broadly flat.
September is a relatively wet time of year in Sirmaur, averaging 176 mm of rainfall. The wettest September on record was 2010 with 524 mm, while the driest was 1982 at 9 mm.
Relative humidity in Sirmaur during September averages 75%. The most humid September was 2025 at 87%, and the least humid was 1987 at 44%.
September receives about 5 kWh/m²/day of solar energy in Sirmaur. The sunniest September was 2001 at 6 kWh/m²/day, and the cloudiest was 1990 at 3.9.
Average wind speed in Sirmaur during September is 1.4 m/s. The windiest Septembers were 2014, 2015 and 2025, among others at 1.7 m/s, while the calmest were 2007, 2019 and 2021, among others at 1.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 25.0°C | 24.3°C | 24.4°C | 24.4°C | 25.0°C | 0°C |
| Avg High | 30.2°C | 28.5°C | 28.9°C | 28.2°C | 28.5°C | -1.7°C |
| Avg Low | 19.8°C | 20.1°C | 19.9°C | 20.7°C | 21.5°C | +1.7°C |
| Avg Rain | 117 mm | 183 mm | 156 mm | 218 mm | 214 mm | +97 mm |
September temperatures in Sirmaur have risen by about 0.5°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 14°C (1994) to a record high of 36.4°C (1987).
Rainfall in September is a relatively wet time of year, averaging 176 mm, with a wettest year of 524 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.4°C per decade while lows rose 0.4°C per decade, narrowing the gap between day and night.
A good time to visit Sirmaur
September is a good time to visit Sirmaur, with days averaging 28.9°C and nights around 20.3°C (mean 24.6°C, warmer than Sirmaur's yearly average) and higher rainfall. October and March 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 | 28.3°C | 25.0°C | 21.8°C | 30.5°C | 20.9°C | 230 mm | 87% | 1.7 m/s | 4.6 |
| 2024 | 28.6°C | 25.4°C | 22.2°C | 31.1°C | 20.4°C | 238 mm | 85% | 1.3 m/s | 4.4 |
| 2023 | 28.7°C | 25.1°C | 21.5°C | 31.7°C | 18.2°C | 107 mm | 82% | 1.3 m/s | 5.1 |
| 2022 | 28.0°C | 24.7°C | 21.4°C | 29.6°C | 18.9°C | 411 mm | 85% | 1.4 m/s | 4.6 |
| 2021 | 27.9°C | 24.6°C | 21.4°C | 29.7°C | 20.0°C | 247 mm | 84% | 1.2 m/s | 4.3 |
| 2020 | 29.7°C | 25.1°C | 20.6°C | 32.2°C | 16.7°C | 49 mm | 76% | 1.5 m/s | 5.6 |
| 2019 | 28.8°C | 25.1°C | 21.5°C | 31.4°C | 19.0°C | 217 mm | 81% | 1.2 m/s | 4.6 |
| 2018 | 27.3°C | 23.8°C | 20.3°C | 30.1°C | 17.5°C | 251 mm | 83% | 1.5 m/s | 4.6 |
| 2017 | 28.7°C | 24.7°C | 20.6°C | 31.0°C | 18.4°C | 214 mm | 78% | 1.6 m/s | 5.1 |
| 2016 | 28.8°C | 24.8°C | 20.8°C | 30.6°C | 19.6°C | 67 mm | 76% | 1.5 m/s | 5.3 |
| 2015 | 29.0°C | 24.5°C | 20.0°C | 31.4°C | 17.8°C | 60 mm | 70% | 1.7 m/s | 5.7 |
| 2014 | 28.2°C | 24.5°C | 20.8°C | 29.7°C | 18.5°C | 159 mm | 79% | 1.7 m/s | 5.3 |
| 2013 | 28.1°C | 24.4°C | 20.7°C | 30.1°C | 18.2°C | 140 mm | 79% | 1.5 m/s | 5.2 |
| 2012 | 27.8°C | 24.5°C | 21.1°C | 29.8°C | 18.1°C | 262 mm | 83% | 1.6 m/s | 5.1 |
| 2011 | 27.7°C | 24.2°C | 20.8°C | 30.3°C | 17.5°C | 287 mm | 83% | 1.4 m/s | 5.1 |
| 2010 🌧️ | 27.1°C | 23.8°C | 20.4°C | 30.3°C | 16.6°C | 524 mm | 85% | 1.3 m/s | 4.4 |
| 2009 | 28.9°C | 24.5°C | 20.0°C | 30.7°C | 17.4°C | 209 mm | 76% | 1.4 m/s | 5.1 |
| 2008 | 28.0°C | 23.8°C | 19.6°C | 30.9°C | 16.8°C | 199 mm | 78% | 1.4 m/s | 5.5 |
| 2007 | 28.5°C | 24.6°C | 20.7°C | 30.3°C | 16.3°C | 131 mm | 77% | 1.2 m/s | 5 |
| 2006 | 28.9°C | 24.4°C | 19.9°C | 31.6°C | 15.5°C | 98 mm | 74% | 1.5 m/s | 5.5 |
| 2005 | 28.3°C | 24.6°C | 20.9°C | 31.9°C | 17.5°C | 271 mm | 79% | 1.2 m/s | 4.4 |
| 2004 | 29.6°C | 24.4°C | 19.3°C | 31.5°C | 17.2°C | 39 mm | 70% | 1.5 m/s | 5.5 |
| 2003 | 28.3°C | 24.6°C | 20.9°C | 29.6°C | 16.9°C | 224 mm | 79% | 1.3 m/s | 4.7 |
| 2002 | 28.3°C | 23.7°C | 19.1°C | 30.9°C | 15.3°C | 203 mm | 73% | 1.4 m/s | 5 |
| 2001 | 29.7°C | 24.3°C | 19.0°C | 31.9°C | 15.6°C | 70 mm | 67% | 1.4 m/s | 6 |
| 2000 | 30.6°C | 25.0°C | 19.5°C | 32.5°C | 15.9°C | 118 mm | 62% | 1.5 m/s | 5.4 |
| 1999 | 31.0°C | 26.3°C | 21.5°C | 35.0°C | 19.0°C | 167 mm | 67% | 1.3 m/s | 4.6 |
| 1998 | 28.6°C | 25.0°C | 21.4°C | 30.3°C | 19.0°C | 166 mm | 78% | 1.2 m/s | 4.4 |
| 1997 | 28.8°C | 24.2°C | 19.6°C | 31.0°C | 14.9°C | 95 mm | 72% | 1.4 m/s | 4.9 |
| 1996 | 28.0°C | 24.0°C | 19.9°C | 30.4°C | 17.6°C | 206 mm | 79% | 1.5 m/s | 4.7 |
| 1995 | 28.1°C | 23.9°C | 19.7°C | 31.0°C | 16.6°C | 195 mm | 77% | 1.5 m/s | 5.1 |
| 1994 | 28.2°C | 23.9°C | 19.6°C | 30.6°C | 14.0°C | 53 mm | 75% | 1.4 m/s | 5.3 |
| 1993 | 27.8°C | 23.9°C | 20.0°C | 30.8°C | 16.2°C | 284 mm | 77% | 1.3 m/s | 4.5 |
| 1992 | 28.1°C | 23.8°C | 19.5°C | 30.8°C | 16.9°C | 126 mm | 75% | 1.4 m/s | 4.9 |
| 1991 | 28.4°C | 23.9°C | 19.5°C | 29.9°C | 15.0°C | 179 mm | 74% | 1.5 m/s | 5 |
| 1990 | 28.1°C | 24.3°C | 20.6°C | 30.7°C | 17.2°C | 363 mm | 82% | 1.3 m/s | 3.9 |
| 1989 | 30.0°C | 24.9°C | 19.8°C | 32.3°C | 17.3°C | 121 mm | 66% | 1.4 m/s | 5.2 |
| 1988 | 28.8°C | 24.6°C | 20.5°C | 31.7°C | 18.3°C | 282 mm | 75% | 1.4 m/s | 4.8 |
| 1987 🔥 | 34.7°C | 27.7°C | 20.6°C | 36.4°C | 17.2°C | 31 mm | 44% | 1.7 m/s | 5.4 |
| 1986 | 32.2°C | 25.8°C | 19.4°C | 34.7°C | 17.4°C | 79 mm | 50% | 1.7 m/s | 5.3 |
| 1985 | 28.2°C | 24.1°C | 19.9°C | 30.3°C | 16.9°C | 143 mm | 75% | 1.3 m/s | 4.7 |
| 1984 ❄️ | 27.2°C | 23.1°C | 19.0°C | 29.5°C | 14.1°C | 146 mm | 77% | 1.4 m/s | 5.2 |
| 1983 | 29.9°C | 25.5°C | 21.2°C | 31.5°C | 18.6°C | 115 mm | 71% | 1.4 m/s | — |
| 1982 | 32.0°C | 25.3°C | 18.5°C | 33.4°C | 15.0°C | 9 mm | 50% | 1.7 m/s | — |
| 1981 | 29.2°C | 24.3°C | 19.5°C | 31.0°C | 17.8°C | 126 mm | 71% | 1.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 28.9°C with lows near 20.3°C (mean 24.6°C), based on 45 years of NASA POWER data.
September averages 176 mm of rainfall in Sirmaur, a relatively wet time of year. The wettest on record was 524 mm in 2010.
The hottest September reached 36.4°C in 1987. The coldest dipped to 14°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 19.6°C to 21.7°C while daytime highs eased from 29.3°C to 28.3°C, narrowing the gap between day and night.
September is one of the warmer months of the year in Sirmaur and a relatively wet time of year, so plan for around 28.9°C daytime highs and 20.3°C at night.
Not quite — September is the 7th coolest month in Sirmaur, averaging 24.6°C.
For September in Sirmaur, pack light layers you can adjust through the day, with typical highs of 28.9°C and lows of 20.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 75% — moderately humid.
Average wind speed in September is 1.4 m/s. The windiest September on record averaged 1.7 m/s (1982).
The wettest September on record was 2010 with 524 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 Sirmaur 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.
