September is one of the warmer months of the year in Gallatin, with average highs near 28.1°C and lows around 15.6°C (mean 21.9°C). It is one of the drier months, averaging 93 mm of rainfall and 69% relative humidity across the period.
September is one of the warmer months of the year in Gallatin. Across 45 years of records, the warmest September in Gallatin was 2019 — when the month averaged 25.6°C — while the coldest was 1982 at 19.2°C. Typical September days reach 28.1°C with nights near 15.6°C. The long-term trend is warming, about 0.3°C per decade.
September is one of the drier months in Gallatin, averaging 93 mm of rainfall. The wettest September on record was 2009 with 198 mm, while the driest was 2019 at 13 mm.
Relative humidity in Gallatin during September averages 69%. The most humid September was 1989 at 82%, and the least humid was 1999 at 44%.
September receives about 4.7 kWh/m²/day of solar energy in Gallatin. The sunniest September was 2019 at 5.5 kWh/m²/day, and the cloudiest were 1989, 2009 and 2018 at 4.
Average wind speed in Gallatin during September is 1.4 m/s. The windiest Septembers were 2000, 2001 and 2006, among others at 1.7 m/s, while the calmest were 2019, 2023 and 2025, 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 | 21.1°C | 21.8°C | 22.0°C | 22.2°C | 22.1°C | +1°C |
| Avg High | 27.3°C | 28.5°C | 28.2°C | 28.2°C | 28.3°C | +1°C |
| Avg Low | 14.9°C | 15.2°C | 15.8°C | 16.2°C | 15.9°C | +1°C |
| Avg Rain | 98 mm | 87 mm | 98 mm | 85 mm | 98 mm | 0 mm |
September temperatures in Gallatin have risen by about 1.7°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 3.4°C (1983) to a record high of 38.8°C (1990).
Rainfall in September is one of the drier months, averaging 93 mm, with a wettest year of 198 mm.
One of the best times to visit Gallatin
September is one of the best times to visit Gallatin. Expect days averaging 28.1°C and nights around 15.6°C (mean 21.9°C) — warmer than Gallatin's yearly average — with higher rainfall (93 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 | 30.4°C | 23.5°C | 16.6°C | 34.3°C | 10.4°C | 95 mm | 64% | 1.2 m/s | 4.9 |
| 2024 | 29.7°C | 23.4°C | 17.1°C | 35.3°C | 9.0°C | 156 mm | 66% | 1.4 m/s | 4.3 |
| 2023 | 29.7°C | 22.9°C | 16.2°C | 33.3°C | 11.4°C | 55 mm | 65% | 1.2 m/s | 4.9 |
| 2022 | 27.8°C | 21.3°C | 14.8°C | 35.5°C | 6.3°C | 75 mm | 69% | 1.5 m/s | 5.1 |
| 2021 | 26.5°C | 21.0°C | 15.5°C | 31.4°C | 8.4°C | 109 mm | 77% | 1.3 m/s | 4.6 |
| 2020 | 25.9°C | 20.5°C | 15.0°C | 31.0°C | 7.7°C | 96 mm | 79% | 1.4 m/s | 4.4 |
| 2019 🔥 | 32.4°C | 25.6°C | 18.9°C | 35.8°C | 14.6°C | 13 mm | 65% | 1.2 m/s | 5.5 |
| 2018 | 29.0°C | 24.1°C | 19.1°C | 35.0°C | 12.9°C | 161 mm | 78% | 1.3 m/s | 4 |
| 2017 | 26.0°C | 20.2°C | 14.4°C | 30.2°C | 8.8°C | 106 mm | 77% | 1.4 m/s | 4.8 |
| 2016 | 29.5°C | 23.1°C | 16.7°C | 33.7°C | 8.2°C | 66 mm | 70% | 1.3 m/s | 5.3 |
| 2015 | 28.6°C | 22.3°C | 16.0°C | 33.7°C | 8.9°C | 83 mm | 69% | 1.3 m/s | 4.8 |
| 2014 | 28.0°C | 21.9°C | 15.8°C | 31.6°C | 7.6°C | 25 mm | 71% | 1.3 m/s | 4.6 |
| 2013 | 26.8°C | 21.3°C | 15.7°C | 31.3°C | 9.0°C | 77 mm | 79% | 1.2 m/s | 4.9 |
| 2012 | 26.6°C | 20.8°C | 14.9°C | 32.3°C | 4.8°C | 128 mm | 73% | 1.5 m/s | 4.6 |
| 2011 | 25.7°C | 20.2°C | 14.6°C | 38.6°C | 8.9°C | 160 mm | 73% | 1.6 m/s | 4.2 |
| 2010 | 29.1°C | 22.3°C | 15.4°C | 35.1°C | 9.1°C | 33 mm | 64% | 1.4 m/s | 5.3 |
| 2009 🌧️ | 26.0°C | 21.5°C | 17.1°C | 30.1°C | 8.1°C | 198 mm | 81% | 1.3 m/s | 4 |
| 2008 | 30.1°C | 23.3°C | 16.6°C | 34.9°C | 11.6°C | 22 mm | 63% | 1.6 m/s | 4.7 |
| 2007 | 31.2°C | 24.4°C | 17.7°C | 36.5°C | 10.0°C | 61 mm | 59% | 1.3 m/s | 4.8 |
| 2006 | 25.8°C | 19.8°C | 13.9°C | 32.0°C | 6.6°C | 132 mm | 73% | 1.7 m/s | 4.4 |
| 2005 | 29.1°C | 22.9°C | 16.6°C | 32.7°C | 7.0°C | 31 mm | 71% | 1.3 m/s | 5.3 |
| 2004 | 27.3°C | 21.4°C | 15.5°C | 31.7°C | 9.3°C | 88 mm | 76% | 1.6 m/s | 4.7 |
| 2003 | 25.4°C | 19.8°C | 14.2°C | 30.6°C | 4.4°C | 155 mm | 77% | 1.4 m/s | 5 |
| 2002 | 30.1°C | 23.8°C | 17.5°C | 36.3°C | 8.9°C | 168 mm | 66% | 1.6 m/s | 4.5 |
| 2001 | 27.8°C | 20.9°C | 14.0°C | 34.6°C | 3.4°C | 63 mm | 65% | 1.7 m/s | 5 |
| 2000 | 28.7°C | 22.0°C | 15.3°C | 33.7°C | 6.0°C | 60 mm | 64% | 1.7 m/s | 4.4 |
| 1999 | 30.2°C | 22.2°C | 14.3°C | 37.7°C | 6.6°C | 36 mm | 44% | 1.5 m/s | 5.1 |
| 1998 | 32.6°C | 25.3°C | 18.0°C | 37.0°C | 9.9°C | 22 mm | 56% | 1.3 m/s | 5.2 |
| 1997 | 28.5°C | 21.5°C | 14.6°C | 34.6°C | 8.7°C | 103 mm | 66% | 1.5 m/s | 4.8 |
| 1996 | 26.1°C | 20.2°C | 14.4°C | 30.6°C | 7.2°C | 173 mm | 74% | 1.5 m/s | 4.5 |
| 1995 | 28.1°C | 21.3°C | 14.6°C | 33.8°C | 5.6°C | 81 mm | 64% | 1.5 m/s | 4.5 |
| 1994 | 27.6°C | 20.6°C | 13.6°C | 32.8°C | 8.0°C | 73 mm | 66% | 1.4 m/s | 4.6 |
| 1993 | 28.1°C | 21.3°C | 14.6°C | 34.4°C | 4.0°C | 91 mm | 66% | 1.7 m/s | 4.2 |
| 1992 | 25.5°C | 20.3°C | 15.1°C | 30.6°C | 3.7°C | 115 mm | 79% | 1.6 m/s | 4.2 |
| 1991 | 27.9°C | 22.1°C | 16.3°C | 34.6°C | 4.1°C | 93 mm | 68% | 1.4 m/s | 4.7 |
| 1990 | 30.0°C | 23.3°C | 16.7°C | 38.8°C | 5.8°C | 88 mm | 63% | 1.4 m/s | 4.7 |
| 1989 | 25.0°C | 20.0°C | 14.9°C | 30.9°C | 3.5°C | 185 mm | 82% | 1.4 m/s | 4 |
| 1988 | 27.9°C | 21.9°C | 15.8°C | 34.0°C | 8.0°C | 139 mm | 73% | 1.6 m/s | 4.2 |
| 1987 | 28.5°C | 22.0°C | 15.6°C | 33.0°C | 10.1°C | 82 mm | 63% | 1.4 m/s | 4.5 |
| 1986 | 28.2°C | 22.8°C | 17.5°C | 32.1°C | 11.3°C | 134 mm | 76% | 1.6 m/s | 4.4 |
| 1985 | 27.8°C | 21.0°C | 14.2°C | 33.5°C | 6.4°C | 83 mm | 63% | 1.6 m/s | 4.9 |
| 1984 | 27.3°C | 20.4°C | 13.5°C | 34.5°C | 6.3°C | 35 mm | 61% | 1.6 m/s | 4.4 |
| 1983 | 29.6°C | 22.7°C | 15.8°C | 36.1°C | 3.4°C | 24 mm | 57% | 1.6 m/s | — |
| 1982 ❄️ | 24.7°C | 19.2°C | 13.8°C | 29.5°C | 5.6°C | 106 mm | 81% | 1.3 m/s | — |
| 1981 | 26.8°C | 20.0°C | 13.1°C | 32.0°C | 6.0°C | 92 mm | 67% | 1.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 28.1°C with lows near 15.6°C (mean 21.9°C), based on 45 years of NASA POWER data.
September averages 93 mm of rainfall in Gallatin, one of the drier months. The wettest on record was 198 mm in 2009.
The hottest September reached 38.8°C in 1990. The coldest dipped to 3.4°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.7°C. Daytime highs moved from 27.2°C to 28.8°C and overnight lows from 14.1°C to 16°C over the same span.
September is one of the warmer months of the year in Gallatin and one of the drier months, so plan for around 28.1°C daytime highs and 15.6°C at night.
Not quite — September is the 9th coolest month in Gallatin, averaging 21.9°C.
For September in Gallatin, pack light layers you can adjust through the day, with typical highs of 28.1°C and lows of 15.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 69% — moderately humid.
Average wind speed in September is 1.4 m/s. The windiest September on record averaged 1.7 m/s (1993).
The wettest September on record was 2009 with 198 mm. On average, September sees 93 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 Gallatin 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.
