September is one of the warmer months of the year in High River, with average highs near 19.1°C and lows around 5.7°C (mean 12.4°C). It is about average for rainfall, averaging 44 mm of rainfall and 61% relative humidity across the period.
September is one of the warmer months of the year in High River. Across 45 years of records, the warmest September in High River was 2025 — when the month averaged 16.7°C — while the coldest was 1985 at 6.9°C. Typical September days reach 19.1°C with nights near 5.7°C. The long-term trend is warming, about 0.7°C per decade.
September is about average for rainfall in High River, averaging 44 mm of rainfall. The wettest September on record was 1985 with 122 mm, while the driest were 1990 and 1994 at 8 mm.
Relative humidity in High River during September averages 61%. The most humid September was 1986 at 76%, and the least humid was 2009 at 47%.
September receives about 3.9 kWh/m²/day of solar energy in High River. The sunniest September was 1990 at 4.8 kWh/m²/day, and the cloudiest was 1986 at 2.9.
Average wind speed in High River during September is 1.2 m/s. The windiest September was 1985 at 1.4 m/s, while the calmest were 2008 and 2025 at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.6°C | 12.9°C | 12.4°C | 12.1°C | 14.9°C | +4.3°C |
| Avg High | 17.0°C | 20.1°C | 19.2°C | 18.6°C | 21.6°C | +4.6°C |
| Avg Low | 4.1°C | 5.6°C | 5.5°C | 5.6°C | 8.3°C | +4.2°C |
| Avg Rain | 62 mm | 28 mm | 51 mm | 47 mm | 30 mm | -32 mm |
September temperatures in High River have risen by about 5.4°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -8.1°C (2019) to a record high of 33.2°C (1998).
Rainfall in September is about average for rainfall, averaging 44 mm, with a wettest year of 122 mm.
One of the best times to visit High River
September is one of the best times to visit High River. Expect days averaging 19.1°C and nights around 5.7°C (mean 12.4°C) — warmer than High River's yearly average — with moderate rainfall (44 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 🔥 | 23.5°C | 16.7°C | 10.0°C | 29.5°C | 5.3°C | 17 mm | 64% | 1 m/s | 4.2 |
| 2024 | 21.3°C | 15.0°C | 8.8°C | 31.3°C | 1.7°C | 64 mm | 65% | 1.1 m/s | 4.1 |
| 2023 | 19.9°C | 13.7°C | 7.6°C | 28.6°C | 2.6°C | 35 mm | 63% | 1.1 m/s | 3.8 |
| 2022 | 22.7°C | 15.7°C | 8.8°C | 32.2°C | 1.2°C | 24 mm | 58% | 1.1 m/s | 4.1 |
| 2021 | 21.4°C | 14.3°C | 7.3°C | 28.2°C | 2.2°C | 12 mm | 54% | 1.2 m/s | 4.1 |
| 2020 | 20.9°C | 13.9°C | 7.0°C | 29.9°C | 0.1°C | 28 mm | 63% | 1.2 m/s | 3.7 |
| 2019 | 16.7°C | 11.3°C | 6.0°C | 26.4°C | -8.1°C | 84 mm | 70% | 1.2 m/s | 3.5 |
| 2018 | 14.6°C | 8.7°C | 2.8°C | 27.7°C | -5.1°C | 38 mm | 69% | 1.1 m/s | 3.1 |
| 2017 | 19.5°C | 12.6°C | 5.7°C | 30.9°C | -0.5°C | 22 mm | 61% | 1.1 m/s | 3.8 |
| 2016 | 17.9°C | 11.7°C | 5.5°C | 25.0°C | 1.2°C | 46 mm | 66% | 1.2 m/s | 3.9 |
| 2015 | 18.0°C | 11.4°C | 4.8°C | 28.5°C | 0.2°C | 66 mm | 66% | 1.1 m/s | 3.9 |
| 2014 | 17.9°C | 11.7°C | 5.4°C | 27.5°C | -8.0°C | 60 mm | 69% | 1.2 m/s | 3.8 |
| 2013 | 20.6°C | 14.2°C | 7.9°C | 30.2°C | 0.0°C | 58 mm | 62% | 1.2 m/s | 4.1 |
| 2012 | 22.6°C | 14.9°C | 7.3°C | 27.3°C | 1.3°C | 11 mm | 53% | 1.2 m/s | 4.3 |
| 2011 | 22.3°C | 14.7°C | 7.1°C | 29.4°C | 0.6°C | 25 mm | 55% | 1.3 m/s | 4.5 |
| 2010 | 16.1°C | 10.0°C | 3.9°C | 25.6°C | -2.4°C | 56 mm | 72% | 1.1 m/s | 3.2 |
| 2009 | 24.0°C | 16.0°C | 7.9°C | 32.3°C | 1.1°C | 10 mm | 47% | 1.3 m/s | 4.5 |
| 2008 | 19.1°C | 12.1°C | 5.1°C | 27.7°C | 0.7°C | 56 mm | 63% | 1 m/s | 4.1 |
| 2007 | 18.0°C | 11.2°C | 4.4°C | 27.0°C | -1.8°C | 50 mm | 63% | 1.1 m/s | 3.9 |
| 2006 | 19.9°C | 13.1°C | 6.4°C | 29.0°C | -1.5°C | 48 mm | 62% | 1.2 m/s | 3.9 |
| 2005 | 16.7°C | 10.6°C | 4.5°C | 25.3°C | -1.0°C | 98 mm | 69% | 1.1 m/s | 4 |
| 2004 | 17.4°C | 11.2°C | 4.9°C | 24.4°C | -2.7°C | 40 mm | 70% | 1.1 m/s | 3.6 |
| 2003 | 19.0°C | 12.3°C | 5.5°C | 32.4°C | -2.6°C | 52 mm | 59% | 1.2 m/s | 3.7 |
| 2002 | 17.1°C | 11.1°C | 5.0°C | 27.8°C | -0.7°C | 87 mm | 66% | 1.2 m/s | 3.5 |
| 2001 | 21.9°C | 14.4°C | 6.8°C | 29.8°C | 3.2°C | 20 mm | 50% | 1.2 m/s | 4.1 |
| 2000 | 18.4°C | 11.7°C | 4.9°C | 28.3°C | -6.7°C | 49 mm | 59% | 1.2 m/s | 3.8 |
| 1999 | 18.6°C | 11.7°C | 4.8°C | 27.6°C | -3.0°C | 23 mm | 56% | 1.2 m/s | 4.3 |
| 1998 | 22.3°C | 14.8°C | 7.3°C | 33.2°C | 0.7°C | 26 mm | 55% | 1.2 m/s | 4.3 |
| 1997 | 22.0°C | 14.7°C | 7.4°C | 29.3°C | -0.6°C | 17 mm | 56% | 1.2 m/s | 4.3 |
| 1996 | 16.0°C | 10.1°C | 4.2°C | 27.1°C | -1.8°C | 59 mm | 65% | 1.3 m/s | 3.2 |
| 1995 | 20.2°C | 13.1°C | 6.0°C | 29.5°C | -3.6°C | 20 mm | 56% | 1.1 m/s | 4.2 |
| 1994 | 23.2°C | 15.2°C | 7.2°C | 29.0°C | 0.8°C | 8 mm | 50% | 1.1 m/s | 4.3 |
| 1993 | 16.8°C | 10.3°C | 3.8°C | 26.4°C | -1.8°C | 54 mm | 68% | 1.2 m/s | 4.3 |
| 1992 | 17.2°C | 10.1°C | 3.0°C | 27.4°C | -4.1°C | 34 mm | 61% | 1.3 m/s | 3.7 |
| 1991 | 20.3°C | 12.9°C | 5.4°C | 28.2°C | -0.7°C | 29 mm | 58% | 1.2 m/s | 4.3 |
| 1990 | 24.0°C | 15.7°C | 7.3°C | 30.6°C | 0.7°C | 8 mm | 50% | 1.2 m/s | 4.8 |
| 1989 | 19.4°C | 12.3°C | 5.3°C | 26.2°C | -1.5°C | 44 mm | 61% | 1.2 m/s | 4.4 |
| 1988 | 19.4°C | 12.4°C | 5.4°C | 32.8°C | -3.6°C | 40 mm | 57% | 1.3 m/s | 3.6 |
| 1987 | 22.1°C | 14.6°C | 7.1°C | 30.0°C | 2.7°C | 26 mm | 54% | 1.1 m/s | 4.2 |
| 1986 | 12.8°C | 7.6°C | 2.4°C | 24.1°C | -1.1°C | 110 mm | 76% | 1.1 m/s | 2.9 |
| 1985 ❄️ 🌧️ | 12.8°C | 6.9°C | 1.0°C | 21.2°C | -6.0°C | 122 mm | 71% | 1.4 m/s | 3.4 |
| 1984 | 14.0°C | 8.1°C | 2.1°C | 26.9°C | -6.4°C | 84 mm | 67% | 1.3 m/s | 3.7 |
| 1983 | 16.0°C | 9.6°C | 3.2°C | 27.2°C | -4.3°C | 18 mm | 60% | 1.3 m/s | — |
| 1982 | 17.1°C | 11.0°C | 4.8°C | 28.1°C | -4.0°C | 85 mm | 67% | 1.3 m/s | — |
| 1981 | 19.5°C | 12.7°C | 5.9°C | 31.2°C | -2.4°C | 26 mm | 59% | 1.1 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 5.7°C (mean 12.4°C), based on 45 years of NASA POWER data.
September averages 44 mm of rainfall in High River, about average for rainfall. The wettest on record was 122 mm in 1985.
The hottest September reached 33.2°C in 1998. The coldest dipped to -8.1°C in 2019.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 5.4°C. Daytime highs moved from 15.9°C to 21.8°C and overnight lows from 3.4°C to 8.5°C over the same span.
September is one of the warmer months of the year in High River and about average for rainfall, so plan for around 19.1°C daytime highs and 5.7°C at night.
Not quite — September is the 9th coolest month in High River, averaging 12.4°C.
For September in High River, pack warm layers and a jacket for chilly mornings, with typical highs of 19.1°C and lows of 5.7°C.
Relative humidity in September averages 61% — moderately humid.
Average wind speed in September is 1.2 m/s. The windiest September on record averaged 1.4 m/s (1985).
The wettest September on record was 1985 with 122 mm. On average, September sees 44 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 High River 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.
