September is one of the warmer months of the year in Dumfries, with average highs near 14.9°C and lows around 9.4°C (mean 12.2°C). It is about average for rainfall, averaging 106 mm of rainfall and 88% relative humidity across the period.
September is one of the warmer months of the year in Dumfries. Across 45 years of records, the warmest September in Dumfries was 2006 — when the month averaged 14.2°C — while the coldest was 1986 at 10.1°C. Typical September days reach 14.9°C with nights near 9.4°C. The long-term trend is warming, about 0.3°C per decade.
September is about average for rainfall in Dumfries, averaging 106 mm of rainfall. The wettest September on record was 1985 with 189 mm, while the driest was 2014 at 18 mm.
Relative humidity in Dumfries during September averages 88%. The most humid September was 1985 at 91%, and the least humid was 1991 at 84%.
September receives about 2.7 kWh/m²/day of solar energy in Dumfries. The sunniest September was 1991 at 3.1 kWh/m²/day, and the cloudiest was 2000 at 2.2.
Average wind speed in Dumfries during September is 4 m/s. The windiest September was 2004 at 5 m/s, while the calmest was 2014 at 2.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.5°C | 11.9°C | 12.5°C | 12.1°C | 12.9°C | +1.4°C |
| Avg High | 14.1°C | 14.8°C | 15.2°C | 14.8°C | 15.8°C | +1.7°C |
| Avg Low | 8.9°C | 9.0°C | 9.7°C | 9.4°C | 9.9°C | +1°C |
| Avg Rain | 122 mm | 90 mm | 102 mm | 111 mm | 108 mm | -14 mm |
September temperatures in Dumfries have risen by about 1.4°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 2.2°C (1986) to a record high of 23.1°C (2021).
Rainfall in September is about average for rainfall, averaging 106 mm, with a wettest year of 189 mm.
One of the best times to visit Dumfries
September is one of the best times to visit Dumfries. Expect days averaging 14.9°C and nights around 9.4°C (mean 12.2°C) — warmer than Dumfries's yearly average — with higher rainfall (106 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 | 14.9°C | 12.3°C | 9.6°C | 17.5°C | 4.0°C | 154 mm | 87% | 4 m/s | 2.8 |
| 2024 | 15.1°C | 11.9°C | 8.6°C | 20.7°C | 4.2°C | 57 mm | 88% | 3.8 m/s | 2.6 |
| 2023 | 16.9°C | 14.1°C | 11.2°C | 22.6°C | 7.2°C | 152 mm | 89% | 4 m/s | 2.9 |
| 2022 | 16.2°C | 13.0°C | 9.8°C | 19.8°C | 5.0°C | 110 mm | 88% | 3.6 m/s | 2.6 |
| 2021 | 17.1°C | 14.1°C | 11.1°C | 23.1°C | 7.2°C | 92 mm | 88% | 3.1 m/s | 2.6 |
| 2020 | 14.8°C | 11.9°C | 9.1°C | 18.5°C | 3.2°C | 85 mm | 89% | 4 m/s | 2.7 |
| 2019 | 15.0°C | 12.3°C | 9.6°C | 18.4°C | 6.7°C | 156 mm | 89% | 3.8 m/s | 2.8 |
| 2018 | 14.0°C | 11.3°C | 8.6°C | 18.0°C | 4.2°C | 110 mm | 87% | 4.7 m/s | 2.6 |
| 2017 | 14.3°C | 11.9°C | 9.6°C | 16.9°C | 6.3°C | 152 mm | 90% | 3.9 m/s | 2.4 |
| 2016 | 16.0°C | 13.6°C | 11.1°C | 20.0°C | 8.1°C | 131 mm | 89% | 4.4 m/s | 2.6 |
| 2015 | 14.6°C | 11.4°C | 8.1°C | 17.4°C | 6.5°C | 50 mm | 88% | 3.1 m/s | 3 |
| 2014 | 16.6°C | 13.3°C | 10.1°C | 19.0°C | 7.2°C | 18 mm | 87% | 2.4 m/s | 2.5 |
| 2013 | 14.2°C | 11.6°C | 8.9°C | 18.2°C | 6.4°C | 92 mm | 90% | 3.9 m/s | 2.6 |
| 2012 | 13.4°C | 10.9°C | 8.4°C | 18.0°C | 3.6°C | 128 mm | 89% | 4.7 m/s | 2.8 |
| 2011 | 14.9°C | 12.6°C | 10.2°C | 20.0°C | 6.5°C | 144 mm | 89% | 4.9 m/s | 2.7 |
| 2010 | 15.2°C | 12.4°C | 9.6°C | 18.7°C | 3.4°C | 133 mm | 88% | 4.1 m/s | 2.8 |
| 2009 | 14.7°C | 12.2°C | 9.7°C | 17.4°C | 6.6°C | 72 mm | 89% | 4.1 m/s | 2.6 |
| 2008 | 14.3°C | 11.9°C | 9.4°C | 16.3°C | 5.7°C | 125 mm | 91% | 3.6 m/s | 2.3 |
| 2007 | 14.5°C | 11.6°C | 8.6°C | 18.3°C | 3.0°C | 70 mm | 89% | 4 m/s | 2.8 |
| 2006 🔥 | 16.9°C | 14.2°C | 11.4°C | 21.1°C | 8.4°C | 148 mm | 90% | 3.9 m/s | 2.7 |
| 2005 | 15.4°C | 12.8°C | 10.1°C | 21.6°C | 5.1°C | 97 mm | 88% | 4.5 m/s | 2.8 |
| 2004 | 15.0°C | 12.4°C | 9.9°C | 19.6°C | 5.6°C | 125 mm | 90% | 5 m/s | 2.7 |
| 2003 | 15.3°C | 12.4°C | 9.5°C | 18.6°C | 5.1°C | 78 mm | 88% | 3.1 m/s | 2.8 |
| 2002 | 15.5°C | 12.6°C | 9.6°C | 19.0°C | 6.3°C | 53 mm | 88% | 2.6 m/s | 2.7 |
| 2001 | 14.5°C | 11.7°C | 9.0°C | 16.8°C | 6.0°C | 91 mm | 89% | 4.2 m/s | 2.3 |
| 2000 | 15.4°C | 12.8°C | 10.1°C | 20.0°C | 7.4°C | 166 mm | 89% | 3.7 m/s | 2.2 |
| 1999 | 16.0°C | 13.4°C | 10.7°C | 21.0°C | 7.2°C | 134 mm | 89% | 4 m/s | 2.7 |
| 1998 | 15.6°C | 12.9°C | 10.2°C | 19.5°C | 5.9°C | 98 mm | 90% | 3.7 m/s | 2.7 |
| 1997 | 14.7°C | 11.8°C | 8.9°C | 17.1°C | 6.0°C | 90 mm | 88% | 4 m/s | 3 |
| 1996 | 15.4°C | 12.3°C | 9.2°C | 20.5°C | 5.2°C | 54 mm | 85% | 3.8 m/s | 3 |
| 1995 | 15.1°C | 11.9°C | 8.7°C | 17.4°C | 4.2°C | 92 mm | 87% | 3.3 m/s | 2.6 |
| 1994 | 13.4°C | 10.8°C | 8.2°C | 17.4°C | 5.2°C | 74 mm | 88% | 3.8 m/s | 2.5 |
| 1993 | 13.8°C | 10.8°C | 7.9°C | 19.5°C | 2.9°C | 81 mm | 87% | 4 m/s | 2.4 |
| 1992 | 13.7°C | 11.3°C | 8.9°C | 19.0°C | 5.9°C | 136 mm | 89% | 4.4 m/s | 2.6 |
| 1991 | 16.0°C | 12.5°C | 9.1°C | 22.4°C | 4.2°C | 71 mm | 84% | 3.8 m/s | 3.1 |
| 1990 | 13.9°C | 11.1°C | 8.4°C | 18.0°C | 4.7°C | 73 mm | 85% | 4.2 m/s | 2.5 |
| 1989 | 14.7°C | 11.8°C | 8.9°C | 18.5°C | 6.8°C | 68 mm | 87% | 4 m/s | 2.5 |
| 1988 | 13.7°C | 11.4°C | 9.1°C | 19.9°C | 2.4°C | 125 mm | 89% | 4.6 m/s | 2.4 |
| 1987 | 13.7°C | 11.3°C | 8.9°C | 17.2°C | 3.5°C | 119 mm | 87% | 4.3 m/s | 2.9 |
| 1986 ❄️ | 13.2°C | 10.1°C | 7.1°C | 16.7°C | 2.2°C | 26 mm | 85% | 3.4 m/s | 2.9 |
| 1985 🌧️ | 14.5°C | 12.0°C | 9.5°C | 18.2°C | 5.4°C | 189 mm | 91% | 3.9 m/s | 2.4 |
| 1984 | 14.0°C | 11.4°C | 8.9°C | 18.6°C | 5.3°C | 135 mm | 86% | 3.8 m/s | 2.4 |
| 1983 | 13.8°C | 11.2°C | 8.6°C | 16.8°C | 4.3°C | 126 mm | 87% | 4.9 m/s | — |
| 1982 | 14.4°C | 11.6°C | 8.9°C | 19.9°C | 4.5°C | 127 mm | 88% | 4.4 m/s | — |
| 1981 | 15.0°C | 12.4°C | 9.8°C | 18.8°C | 7.4°C | 183 mm | 87% | 4.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 14.9°C with lows near 9.4°C (mean 12.2°C), based on 45 years of NASA POWER data.
September averages 106 mm of rainfall in Dumfries, about average for rainfall. The wettest on record was 189 mm in 1985.
The hottest September reached 23.1°C in 2021. The coldest dipped to 2.2°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.4°C. Daytime highs moved from 14.3°C to 16°C and overnight lows from 9.1°C to 10.1°C over the same span.
September is one of the warmer months of the year in Dumfries and about average for rainfall, so plan for around 14.9°C daytime highs and 9.4°C at night.
Not quite — September is the 9th coolest month in Dumfries, averaging 12.2°C.
For September in Dumfries, pack light layers you can adjust through the day, with typical highs of 14.9°C and lows of 9.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 88% — quite humid.
Average wind speed in September is 4 m/s. The windiest September on record averaged 5 m/s (2004).
The wettest September on record was 1985 with 189 mm. On average, September sees 106 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 Dumfries 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.
