September is one of the cooler months of the year in Kollam, with average highs near 27.7°C and lows around 23°C (mean 25.4°C). It is a relatively wet time of year, averaging 209 mm of rainfall and 89% relative humidity across the period.
September is one of the cooler months of the year in Kollam. Across 45 years of records, the warmest September in Kollam was 2024 — when the month averaged 26.2°C — while the coldest was 1992 at 24.7°C. Typical September days reach 27.7°C with nights near 23°C. The long-term trend is warming, about 0.2°C per decade.
September is a relatively wet time of year in Kollam, averaging 209 mm of rainfall. The wettest September on record was 1981 with 520 mm, while the driest was 1991 at 16 mm.
Relative humidity in Kollam during September averages 89%. The most humid Septembers were 1988, 1998 and 2007, among others at 91%, and the least humid was 1990 at 83%.
September receives about 5.4 kWh/m²/day of solar energy in Kollam. The sunniest September was 2002 at 6.4 kWh/m²/day, and the cloudiest were 1996 and 2023 at 4.5.
Average wind speed in Kollam during September is 1.9 m/s. The windiest Septembers were 1998 and 2016 at 2.3 m/s, while the calmest were 2004, 2015 and 2019 at 1.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 25.1°C | 25.3°C | 25.4°C | 25.5°C | 25.8°C | +0.7°C |
| Avg High | 27.4°C | 27.6°C | 27.7°C | 28.0°C | 28.0°C | +0.6°C |
| Avg Low | 22.7°C | 22.9°C | 23.1°C | 23.2°C | 23.5°C | +0.8°C |
| Avg Rain | 218 mm | 167 mm | 254 mm | 183 mm | 237 mm | +20 mm |
September temperatures in Kollam have risen by about 0.8°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 20.6°C (1992) to a record high of 31°C (2002).
Rainfall in September is a relatively wet time of year, averaging 209 mm, with a wettest year of 520 mm.
A good time to visit Kollam
September is a good time to visit Kollam, with days averaging 27.7°C and nights around 23°C (mean 25.4°C, close to Kollam's yearly average) and higher rainfall. January and December 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 | 28.0°C | 26.0°C | 24.0°C | 29.3°C | 23.4°C | 190 mm | 91% | 2 m/s | 5.5 |
| 2024 🔥 | 28.4°C | 26.2°C | 24.0°C | 30.2°C | 23.4°C | 135 mm | 90% | 2 m/s | 5.7 |
| 2023 | 28.4°C | 25.9°C | 23.5°C | 29.3°C | 22.6°C | 343 mm | 87% | 1.8 m/s | 4.5 |
| 2022 | 28.0°C | 25.4°C | 22.9°C | 29.7°C | 22.1°C | 99 mm | 89% | 1.8 m/s | 5.8 |
| 2021 | 27.8°C | 25.7°C | 23.5°C | 29.1°C | 22.7°C | 238 mm | 90% | 2 m/s | 5.4 |
| 2020 | 27.3°C | 25.3°C | 23.2°C | 28.4°C | 21.6°C | 419 mm | 91% | 1.9 m/s | 4.7 |
| 2019 | 27.8°C | 25.6°C | 23.4°C | 29.4°C | 22.3°C | 286 mm | 90% | 1.6 m/s | 5.2 |
| 2018 | 28.6°C | 25.6°C | 22.7°C | 30.0°C | 21.6°C | 122 mm | 88% | 1.7 m/s | 6.1 |
| 2017 | 27.5°C | 25.5°C | 23.4°C | 29.0°C | 22.2°C | 314 mm | 91% | 1.8 m/s | 5.4 |
| 2016 | 28.3°C | 25.6°C | 22.9°C | 29.6°C | 21.1°C | 31 mm | 86% | 2.3 m/s | 6 |
| 2015 | 28.1°C | 25.9°C | 23.6°C | 30.4°C | 22.5°C | 233 mm | 89% | 1.6 m/s | 5.2 |
| 2014 | 27.7°C | 25.5°C | 23.4°C | 29.7°C | 22.6°C | 189 mm | 90% | 1.9 m/s | 5.7 |
| 2013 | 27.6°C | 25.3°C | 23.0°C | 29.5°C | 21.9°C | 174 mm | 89% | 2.1 m/s | 5.3 |
| 2012 | 28.2°C | 25.7°C | 23.3°C | 29.5°C | 22.2°C | 113 mm | 87% | 1.9 m/s | 5.9 |
| 2011 | 27.8°C | 25.4°C | 22.9°C | 29.5°C | 21.9°C | 164 mm | 88% | 2 m/s | 5.5 |
| 2010 | 27.9°C | 25.4°C | 22.9°C | 29.6°C | 21.8°C | 206 mm | 89% | 1.7 m/s | 5.3 |
| 2009 | 27.8°C | 25.5°C | 23.3°C | 29.8°C | 22.5°C | 233 mm | 90% | 2 m/s | 5.6 |
| 2008 | 28.0°C | 25.3°C | 22.7°C | 29.1°C | 21.1°C | 230 mm | 89% | 1.8 m/s | 5.9 |
| 2007 | 27.0°C | 25.1°C | 23.2°C | 28.3°C | 22.3°C | 375 mm | 91% | 2 m/s | 5 |
| 2006 | 27.0°C | 25.1°C | 23.1°C | 28.7°C | 22.1°C | 462 mm | 91% | 1.9 m/s | 5 |
| 2005 | 27.4°C | 25.3°C | 23.2°C | 28.8°C | 22.6°C | 276 mm | 91% | 2.2 m/s | 5.5 |
| 2004 | 27.1°C | 24.9°C | 22.8°C | 28.5°C | 21.8°C | 311 mm | 90% | 1.6 m/s | 5.3 |
| 2003 | 28.6°C | 26.0°C | 23.4°C | 30.4°C | 22.8°C | 29 mm | 87% | 2 m/s | 6.2 |
| 2002 | 29.1°C | 26.0°C | 23.0°C | 31.0°C | 21.9°C | 70 mm | 84% | 1.9 m/s | 6.4 |
| 2001 | 27.8°C | 25.4°C | 23.0°C | 30.0°C | 21.3°C | 431 mm | 89% | 1.9 m/s | 5.3 |
| 2000 | 27.6°C | 25.4°C | 23.2°C | 29.2°C | 22.2°C | 128 mm | 89% | 1.8 m/s | 5.4 |
| 1999 | 28.3°C | 25.7°C | 23.0°C | 29.4°C | 22.1°C | 36 mm | 86% | 1.8 m/s | 6.1 |
| 1998 | 26.8°C | 25.0°C | 23.2°C | 28.2°C | 22.3°C | 461 mm | 91% | 2.3 m/s | 5.2 |
| 1997 | 27.5°C | 25.2°C | 23.0°C | 29.1°C | 22.2°C | 425 mm | 90% | 1.8 m/s | 5.2 |
| 1996 | 26.9°C | 24.8°C | 22.8°C | 28.3°C | 22.2°C | 216 mm | 90% | 2.1 m/s | 4.5 |
| 1995 | 27.9°C | 25.5°C | 23.1°C | 29.2°C | 21.2°C | 123 mm | 89% | 2.2 m/s | 5.5 |
| 1994 | 27.5°C | 25.1°C | 22.7°C | 29.9°C | 21.3°C | 130 mm | 89% | 1.9 m/s | 5.2 |
| 1993 | 27.9°C | 25.4°C | 22.8°C | 29.4°C | 21.7°C | 40 mm | 86% | 1.9 m/s | 5.3 |
| 1992 ❄️ | 26.8°C | 24.7°C | 22.6°C | 28.3°C | 20.6°C | 182 mm | 90% | 1.9 m/s | 5.2 |
| 1991 | 28.2°C | 25.6°C | 23.0°C | 29.6°C | 22.3°C | 16 mm | 87% | 1.9 m/s | 5.6 |
| 1990 | 28.6°C | 25.8°C | 23.0°C | 30.2°C | 21.7°C | 37 mm | 83% | 2.1 m/s | 5.3 |
| 1989 | 27.2°C | 25.0°C | 22.7°C | 28.7°C | 21.7°C | 274 mm | 89% | 2.1 m/s | 4.8 |
| 1988 | 26.7°C | 24.9°C | 23.1°C | 28.0°C | 22.1°C | 513 mm | 91% | 2.2 m/s | 4.9 |
| 1987 | 28.0°C | 25.6°C | 23.2°C | 29.7°C | 22.5°C | 150 mm | 88% | 1.9 m/s | 5.2 |
| 1986 | 27.5°C | 25.1°C | 22.7°C | 29.1°C | 22.2°C | 101 mm | 87% | 2 m/s | 4.8 |
| 1985 | 27.6°C | 25.0°C | 22.4°C | 29.6°C | 21.3°C | 81 mm | 87% | 1.9 m/s | 5.5 |
| 1984 | 28.3°C | 25.3°C | 22.4°C | 30.7°C | 20.8°C | 57 mm | 85% | 1.9 m/s | 5.7 |
| 1983 | 27.1°C | 24.9°C | 22.6°C | 28.6°C | 21.7°C | 230 mm | 88% | 2 m/s | — |
| 1982 | 27.7°C | 25.1°C | 22.5°C | 28.8°C | 21.9°C | 32 mm | 87% | 1.8 m/s | — |
| 1981 🌧️ | 26.8°C | 24.9°C | 22.9°C | 28.4°C | 22.2°C | 520 mm | 91% | 2 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 27.7°C with lows near 23°C (mean 25.4°C), based on 45 years of NASA POWER data.
September averages 209 mm of rainfall in Kollam, a relatively wet time of year. The wettest on record was 520 mm in 1981.
The hottest September reached 31°C in 2002. The coldest dipped to 20.6°C in 1992.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.8°C. Daytime highs moved from 27.5°C to 28.1°C and overnight lows from 22.6°C to 23.6°C over the same span.
September is one of the cooler months of the year in Kollam and a relatively wet time of year, so plan for around 27.7°C daytime highs and 23°C at night.
Not quite — September is the 6th coolest month in Kollam, averaging 25.4°C.
For September in Kollam, pack light layers you can adjust through the day, with typical highs of 27.7°C and lows of 23°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 89% — quite humid.
Average wind speed in September is 1.9 m/s. The windiest September on record averaged 2.3 m/s (1998).
The wettest September on record was 1981 with 520 mm. On average, September sees 209 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 Kollam 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.
