September is one of the warmer months of the year in East Sikkim, with average highs near 16.1°C and lows around 8.4°C (mean 12.3°C). It is a relatively wet time of year, averaging 145 mm of rainfall and 88% relative humidity across the period.
September is one of the warmer months of the year in East Sikkim. Across 45 years of records, the warmest September in East Sikkim was 2023 — when the month averaged 13.1°C — while the coldest was 1984 at 11.1°C. Typical September days reach 16.1°C with nights near 8.4°C. The long-term trend is warming, about 0.2°C per decade.
September is a relatively wet time of year in East Sikkim, averaging 145 mm of rainfall. The wettest September on record was 2024 with 519 mm, while the driest was 2008 at 56 mm.
Relative humidity in East Sikkim during September averages 88%. The most humid September was 2020 at 93%, and the least humid was 2005 at 85%.
September receives about 3.9 kWh/m²/day of solar energy in East Sikkim. The sunniest September was 1997 at 4.6 kWh/m²/day, and the cloudiest were 2016 and 2020 at 3.3.
Average wind speed in East Sikkim during September is 1.5 m/s. The windiest September was 1983 at 1.7 m/s, while the calmest were 2023, 2024 and 2025 at 1.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.9°C | 12.2°C | 12.2°C | 12.4°C | 12.8°C | +0.9°C |
| Avg High | 15.7°C | 16.3°C | 16.2°C | 16.0°C | 16.2°C | +0.5°C |
| Avg Low | 8.0°C | 8.1°C | 8.2°C | 8.8°C | 9.4°C | +1.4°C |
| Avg Rain | 115 mm | 96 mm | 103 mm | 178 mm | 288 mm | +173 mm |
September temperatures in East Sikkim have risen by about 1.1°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 1.6°C (2000) to a record high of 20°C (2004).
Rainfall in September is a relatively wet time of year, averaging 145 mm, with a wettest year of 519 mm.
One of the best times to visit East Sikkim
September is one of the best times to visit East Sikkim. Expect days averaging 16.1°C and nights around 8.4°C (mean 12.3°C) — warmer than East Sikkim's yearly average — with higher rainfall (145 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 16.5°C | 13.0°C | 9.5°C | 18.4°C | 7.2°C | 243 mm | 90% | 1.3 m/s | 3.8 |
| 2024 🌧️ | 16.7°C | 13.0°C | 9.3°C | 18.8°C | 6.2°C | 519 mm | 89% | 1.3 m/s | 4 |
| 2023 🔥 | 16.7°C | 13.1°C | 9.4°C | 19.0°C | 7.2°C | 154 mm | 88% | 1.3 m/s | 4.2 |
| 2022 | 15.7°C | 12.7°C | 9.6°C | 17.4°C | 8.2°C | 231 mm | 93% | 1.6 m/s | 3.4 |
| 2021 | 15.9°C | 12.3°C | 8.7°C | 18.8°C | 6.5°C | 197 mm | 90% | 1.4 m/s | 4.1 |
| 2020 | 15.9°C | 12.9°C | 9.9°C | 18.2°C | 8.1°C | 382 mm | 93% | 1.4 m/s | 3.3 |
| 2019 | 15.4°C | 12.1°C | 8.8°C | 18.2°C | 4.8°C | 239 mm | 91% | 1.5 m/s | 3.5 |
| 2018 | 16.2°C | 12.8°C | 9.3°C | 18.4°C | 6.9°C | 202 mm | 90% | 1.4 m/s | 4 |
| 2017 | 16.1°C | 12.8°C | 9.4°C | 18.7°C | 7.4°C | 166 mm | 92% | 1.4 m/s | 3.8 |
| 2016 | 15.2°C | 11.9°C | 8.7°C | 17.1°C | 6.9°C | 263 mm | 92% | 1.5 m/s | 3.3 |
| 2015 | 16.2°C | 12.8°C | 9.3°C | 17.8°C | 7.6°C | 137 mm | 91% | 1.5 m/s | 4 |
| 2014 | 15.7°C | 12.0°C | 8.4°C | 18.0°C | 4.6°C | 138 mm | 90% | 1.6 m/s | 3.8 |
| 2013 | 16.4°C | 12.3°C | 8.2°C | 17.9°C | 4.8°C | 104 mm | 86% | 1.4 m/s | 4.2 |
| 2012 | 16.6°C | 12.7°C | 8.7°C | 18.6°C | 6.4°C | 166 mm | 88% | 1.4 m/s | 3.9 |
| 2011 | 16.2°C | 12.2°C | 8.3°C | 18.3°C | 4.7°C | 169 mm | 89% | 1.4 m/s | 3.7 |
| 2010 | 15.8°C | 12.1°C | 8.4°C | 17.3°C | 6.9°C | 193 mm | 90% | 1.5 m/s | 3.6 |
| 2009 | 16.3°C | 12.4°C | 8.6°C | 18.0°C | 5.8°C | 72 mm | 87% | 1.5 m/s | 4.1 |
| 2008 | 15.9°C | 12.0°C | 8.1°C | 17.4°C | 6.6°C | 56 mm | 87% | 1.5 m/s | 3.8 |
| 2007 | 15.8°C | 12.0°C | 8.1°C | 18.6°C | 3.1°C | 169 mm | 87% | 1.4 m/s | 3.7 |
| 2006 | 16.1°C | 12.1°C | 8.1°C | 19.1°C | 5.6°C | 179 mm | 87% | 1.4 m/s | 3.9 |
| 2005 | 17.0°C | 12.5°C | 8.0°C | 19.5°C | 5.0°C | 80 mm | 85% | 1.4 m/s | 4.3 |
| 2004 | 16.4°C | 12.3°C | 8.3°C | 20.0°C | 5.4°C | 92 mm | 87% | 1.4 m/s | 3.6 |
| 2003 | 16.8°C | 12.9°C | 9.1°C | 18.7°C | 6.4°C | 73 mm | 88% | 1.6 m/s | 3.6 |
| 2002 | 16.0°C | 11.7°C | 7.4°C | 17.3°C | 4.5°C | 71 mm | 85% | 1.5 m/s | 3.7 |
| 2001 | 16.1°C | 12.4°C | 8.6°C | 17.5°C | 7.5°C | 114 mm | 88% | 1.4 m/s | 3.7 |
| 2000 | 15.7°C | 11.6°C | 7.4°C | 18.0°C | 1.6°C | 125 mm | 87% | 1.4 m/s | 3.9 |
| 1999 | 16.4°C | 12.4°C | 8.3°C | 18.8°C | 5.9°C | 97 mm | 88% | 1.5 m/s | 4.2 |
| 1998 | 16.8°C | 12.6°C | 8.5°C | 18.3°C | 6.7°C | 95 mm | 87% | 1.4 m/s | 4.2 |
| 1997 | 15.4°C | 11.5°C | 7.7°C | 17.4°C | 3.9°C | 124 mm | 89% | 1.5 m/s | 4.6 |
| 1996 | 16.2°C | 12.2°C | 8.1°C | 17.1°C | 6.5°C | 64 mm | 87% | 1.6 m/s | 4.5 |
| 1995 | 16.7°C | 12.4°C | 8.1°C | 19.4°C | 5.6°C | 77 mm | 86% | 1.6 m/s | 4.2 |
| 1994 | 17.1°C | 12.7°C | 8.3°C | 18.9°C | 5.4°C | 63 mm | 85% | 1.5 m/s | 4.5 |
| 1993 | 16.3°C | 12.1°C | 7.9°C | 18.1°C | 6.3°C | 62 mm | 86% | 1.6 m/s | 3.6 |
| 1992 | 16.5°C | 12.0°C | 7.6°C | 19.4°C | 4.4°C | 79 mm | 86% | 1.5 m/s | 4.3 |
| 1991 | 15.3°C | 11.9°C | 8.4°C | 17.4°C | 6.5°C | 179 mm | 90% | 1.4 m/s | 4 |
| 1990 | 16.3°C | 12.3°C | 8.3°C | 18.5°C | 6.0°C | 116 mm | 88% | 1.6 m/s | 3.6 |
| 1989 | 15.9°C | 12.3°C | 8.6°C | 18.4°C | 6.4°C | 123 mm | 90% | 1.5 m/s | 3.8 |
| 1988 | 16.3°C | 12.3°C | 8.4°C | 19.0°C | 5.1°C | 76 mm | 88% | 1.5 m/s | 3.7 |
| 1987 | 15.7°C | 12.0°C | 8.4°C | 17.5°C | 6.0°C | 134 mm | 90% | 1.4 m/s | 3.8 |
| 1986 | 15.5°C | 11.5°C | 7.5°C | 17.8°C | 3.9°C | 102 mm | 87% | 1.5 m/s | 4.1 |
| 1985 | 15.3°C | 11.6°C | 7.8°C | 18.3°C | 5.2°C | 119 mm | 89% | 1.6 m/s | 3.7 |
| 1984 ❄️ | 14.8°C | 11.1°C | 7.4°C | 17.3°C | 4.6°C | 161 mm | 89% | 1.5 m/s | 3.8 |
| 1983 | 16.3°C | 12.4°C | 8.6°C | 18.7°C | 5.4°C | 106 mm | 89% | 1.7 m/s | — |
| 1982 | 16.2°C | 12.0°C | 7.8°C | 18.5°C | 2.8°C | 90 mm | 87% | 1.5 m/s | — |
| 1981 | 15.2°C | 11.5°C | 7.9°C | 18.4°C | 5.9°C | 120 mm | 88% | 1.5 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 16.1°C with lows near 8.4°C (mean 12.3°C), based on 45 years of NASA POWER data.
September averages 145 mm of rainfall in East Sikkim, a relatively wet time of year. The wettest on record was 519 mm in 2024.
The hottest September reached 20°C in 2004. The coldest dipped to 1.6°C in 2000.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.1°C. Daytime highs moved from 15.6°C to 16.3°C and overnight lows from 7.9°C to 9.3°C over the same span.
September is one of the warmer months of the year in East Sikkim and a relatively wet time of year, so plan for around 16.1°C daytime highs and 8.4°C at night.
Not quite — September is the 9th coolest month in East Sikkim, averaging 12.3°C.
For September in East Sikkim, pack light layers you can adjust through the day, with typical highs of 16.1°C and lows of 8.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 88% — quite humid.
Average wind speed in September is 1.5 m/s. The windiest September on record averaged 1.7 m/s (1983).
The wettest September on record was 2024 with 519 mm. On average, September sees 145 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 East Sikkim 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.
