September is one of the warmer months of the year in Trail, with average highs near 19.1°C and lows around 5.9°C (mean 12.5°C). It is one of the drier months, averaging 38 mm of rainfall and 61% relative humidity across the period.
September is one of the warmer months of the year in Trail. Across 45 years of records, the warmest September in Trail was 2025 — when the month averaged 16.6°C — while the coldest was 1985 at 8.2°C. Typical September days reach 19.1°C with nights near 5.9°C. The long-term trend is warming, about 0.5°C per decade.
September is one of the drier months in Trail, averaging 38 mm of rainfall. The wettest September on record was 2013 with 112 mm, while the driest was 1990 at 2 mm.
Relative humidity in Trail during September averages 61%. The most humid September was 2013 at 76%, and the least humid was 1987 at 45%.
September receives about 3.9 kWh/m²/day of solar energy in Trail. The sunniest Septembers were 1990 and 1993 at 4.8 kWh/m²/day, and the cloudiest was 2019 at 3.
Average wind speed in Trail during September is 0.4 m/s. The windiest September was 1990 at 0.5 m/s, while the calmest was 1986 at 0.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.0°C | 13.1°C | 12.6°C | 12.1°C | 14.2°C | +3.2°C |
| Avg High | 17.4°C | 19.9°C | 19.6°C | 18.5°C | 20.7°C | +3.3°C |
| Avg Low | 4.5°C | 6.3°C | 5.7°C | 5.7°C | 7.8°C | +3.3°C |
| Avg Rain | 47 mm | 30 mm | 29 mm | 46 mm | 37 mm | -10 mm |
September temperatures in Trail have risen by about 4.5°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -6.3°C (2000) to a record high of 35.1°C (1988).
Rainfall in September is one of the drier months, averaging 38 mm, with a wettest year of 112 mm.
One of the best times to visit Trail
September is one of the best times to visit Trail. Expect days averaging 19.1°C and nights around 5.9°C (mean 12.5°C) — warmer than Trail's yearly average — with moderate rainfall (38 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 🔥 | 23.3°C | 16.6°C | 9.9°C | 33.5°C | 3.6°C | 26 mm | 65% | 0.3 m/s | 4 |
| 2024 | 22.0°C | 15.1°C | 8.3°C | 30.5°C | -0.6°C | 21 mm | 61% | 0.3 m/s | 4.2 |
| 2023 | 18.5°C | 12.6°C | 6.7°C | 25.0°C | -2.0°C | 45 mm | 68% | 0.3 m/s | 3.7 |
| 2022 | 21.3°C | 14.6°C | 7.9°C | 30.4°C | 1.3°C | 31 mm | 61% | 0.4 m/s | 4 |
| 2021 | 18.9°C | 12.6°C | 6.4°C | 27.7°C | -0.7°C | 63 mm | 64% | 0.3 m/s | 3.6 |
| 2020 | 20.2°C | 13.8°C | 7.3°C | 28.1°C | 0.6°C | 36 mm | 65% | 0.4 m/s | 3.8 |
| 2019 | 16.3°C | 11.1°C | 5.9°C | 26.7°C | -4.2°C | 84 mm | 74% | 0.3 m/s | 3 |
| 2018 | 16.3°C | 10.2°C | 4.2°C | 25.4°C | -0.9°C | 45 mm | 67% | 0.4 m/s | 3.6 |
| 2017 | 19.3°C | 13.0°C | 6.8°C | 30.2°C | 0.6°C | 24 mm | 63% | 0.4 m/s | 3.7 |
| 2016 | 17.3°C | 11.2°C | 5.0°C | 23.9°C | 0.3°C | 43 mm | 68% | 0.3 m/s | 3.5 |
| 2015 | 17.5°C | 10.9°C | 4.3°C | 27.9°C | -1.2°C | 35 mm | 63% | 0.4 m/s | 3.5 |
| 2014 | 19.6°C | 12.8°C | 6.1°C | 26.1°C | -3.1°C | 31 mm | 66% | 0.4 m/s | 4.1 |
| 2013 🌧️ | 18.2°C | 12.8°C | 7.4°C | 28.3°C | 0.5°C | 112 mm | 76% | 0.3 m/s | 3.2 |
| 2012 | 21.5°C | 14.0°C | 6.5°C | 26.6°C | 0.3°C | 19 mm | 58% | 0.4 m/s | 4.6 |
| 2011 | 22.0°C | 14.3°C | 6.6°C | 29.9°C | 1.0°C | 14 mm | 54% | 0.4 m/s | 4.5 |
| 2010 | 16.7°C | 10.6°C | 4.5°C | 24.9°C | -2.3°C | 49 mm | 73% | 0.3 m/s | 3.2 |
| 2009 | 22.3°C | 14.8°C | 7.3°C | 29.8°C | 0.0°C | 15 mm | 49% | 0.4 m/s | 4.4 |
| 2008 | 20.3°C | 12.9°C | 5.6°C | 29.9°C | 0.3°C | 21 mm | 52% | 0.4 m/s | 4.2 |
| 2007 | 18.8°C | 11.8°C | 4.9°C | 27.6°C | -2.0°C | 21 mm | 57% | 0.3 m/s | 4 |
| 2006 | 21.2°C | 13.9°C | 6.7°C | 31.9°C | -1.2°C | 12 mm | 54% | 0.4 m/s | 4.2 |
| 2005 | 17.3°C | 10.9°C | 4.5°C | 25.7°C | -2.0°C | 41 mm | 61% | 0.3 m/s | 3.9 |
| 2004 | 16.9°C | 10.9°C | 5.0°C | 23.5°C | -1.8°C | 53 mm | 69% | 0.3 m/s | 3.3 |
| 2003 | 20.7°C | 13.4°C | 6.2°C | 32.1°C | 0.6°C | 36 mm | 55% | 0.3 m/s | 4 |
| 2002 | 18.9°C | 12.2°C | 5.5°C | 27.9°C | -0.1°C | 22 mm | 56% | 0.4 m/s | 3.9 |
| 2001 | 22.3°C | 14.5°C | 6.7°C | 30.1°C | 1.5°C | 21 mm | 47% | 0.4 m/s | 4.2 |
| 2000 | 17.1°C | 10.7°C | 4.4°C | 25.7°C | -6.3°C | 48 mm | 64% | 0.3 m/s | 3.5 |
| 1999 | 18.3°C | 11.2°C | 4.1°C | 25.2°C | -3.1°C | 9 mm | 56% | 0.4 m/s | 4.3 |
| 1998 | 22.8°C | 15.9°C | 9.0°C | 30.3°C | 3.4°C | 23 mm | 56% | 0.4 m/s | 4.5 |
| 1997 | 18.1°C | 12.2°C | 6.3°C | 26.7°C | 2.1°C | 99 mm | 73% | 0.3 m/s | 3.7 |
| 1996 | 16.4°C | 10.3°C | 4.3°C | 27.5°C | -2.4°C | 35 mm | 66% | 0.4 m/s | 3.2 |
| 1995 | 21.0°C | 14.0°C | 7.1°C | 28.7°C | 0.7°C | 42 mm | 55% | 0.4 m/s | 4.4 |
| 1994 | 22.6°C | 15.3°C | 8.1°C | 29.1°C | 2.6°C | 22 mm | 48% | 0.4 m/s | 4.1 |
| 1993 | 19.2°C | 12.3°C | 5.4°C | 27.0°C | -0.5°C | 20 mm | 58% | 0.4 m/s | 4.8 |
| 1992 | 16.9°C | 10.5°C | 4.1°C | 25.2°C | -2.1°C | 32 mm | 58% | 0.3 m/s | 3.8 |
| 1991 | 20.4°C | 13.1°C | 5.8°C | 26.3°C | 0.2°C | 14 mm | 57% | 0.4 m/s | 4.6 |
| 1990 | 23.5°C | 16.0°C | 8.5°C | 28.1°C | 3.3°C | 2 mm | 49% | 0.5 m/s | 4.8 |
| 1989 | 20.4°C | 13.0°C | 5.6°C | 25.7°C | 1.5°C | 7 mm | 53% | 0.4 m/s | 4.4 |
| 1988 | 19.6°C | 12.7°C | 5.8°C | 35.1°C | -0.9°C | 73 mm | 56% | 0.3 m/s | 3.6 |
| 1987 | 22.8°C | 15.4°C | 8.0°C | 30.9°C | 1.5°C | 15 mm | 45% | 0.4 m/s | 4.6 |
| 1986 | 14.2°C | 8.8°C | 3.3°C | 25.9°C | -1.1°C | 86 mm | 71% | 0.2 m/s | 3.3 |
| 1985 ❄️ | 14.1°C | 8.2°C | 2.3°C | 20.9°C | -4.2°C | 82 mm | 67% | 0.3 m/s | 3.6 |
| 1984 | 15.6°C | 9.1°C | 2.7°C | 24.9°C | -4.7°C | 37 mm | 63% | 0.3 m/s | 3.5 |
| 1983 | 14.9°C | 8.8°C | 2.7°C | 19.9°C | -4.1°C | 20 mm | 67% | 0.4 m/s | — |
| 1982 | 16.8°C | 10.9°C | 5.1°C | 29.4°C | -3.1°C | 58 mm | 73% | 0.3 m/s | — |
| 1981 | 18.3°C | 11.8°C | 5.4°C | 30.7°C | -2.4°C | 46 mm | 63% | 0.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 19.1°C with lows near 5.9°C (mean 12.5°C), based on 45 years of NASA POWER data.
September averages 38 mm of rainfall in Trail, one of the drier months. The wettest on record was 112 mm in 2013.
The hottest September reached 35.1°C in 1988. The coldest dipped to -6.3°C in 2000.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 4.5°C. Daytime highs moved from 15.9°C to 20.8°C and overnight lows from 3.6°C to 7.8°C over the same span.
September is one of the warmer months of the year in Trail and one of the drier months, so plan for around 19.1°C daytime highs and 5.9°C at night.
Not quite — September is the 9th coolest month in Trail, averaging 12.5°C.
For September in Trail, pack warm layers and a jacket for chilly mornings, with typical highs of 19.1°C and lows of 5.9°C.
Relative humidity in September averages 61% — moderately humid.
Average wind speed in September is 0.4 m/s. The windiest September on record averaged 0.5 m/s (1990).
The wettest September on record was 2013 with 112 mm. On average, September sees 38 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 Trail 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.
