September is one of the warmer months of the year in Sault Ste. Marie, with average highs near 18.1°C and lows around 9.7°C (mean 13.9°C). It is a relatively wet time of year, averaging 94 mm of rainfall and 81% relative humidity across the period.
September is one of the warmer months of the year in Sault Ste. Marie. Across 45 years of records, the warmest September in Sault Ste. Marie was 2024 — when the month averaged 17.4°C — while the coldest was 1993 at 10.5°C. Typical September days reach 18.1°C with nights near 9.7°C. The long-term trend is warming, about 0.8°C per decade.
September is a relatively wet time of year in Sault Ste. Marie, averaging 94 mm of rainfall. The wettest September on record was 2010 with 208 mm, while the driest was 2009 at 31 mm.
Relative humidity in Sault Ste. Marie during September averages 81%. The most humid September was 1982 at 86%, and the least humid was 2012 at 75%.
September receives about 3.7 kWh/m²/day of solar energy in Sault Ste. Marie. The sunniest September was 2024 at 4.5 kWh/m²/day, and the cloudiest was 1986 at 2.9.
Average wind speed in Sault Ste. Marie during September is 1.5 m/s. The windiest Septembers were 2000 and 2010 at 1.9 m/s, while the calmest were 1994, 1996 and 2017, among others at 1.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.7°C | 12.9°C | 14.6°C | 14.6°C | 15.3°C | +2.6°C |
| Avg High | 17.0°C | 17.0°C | 18.8°C | 18.7°C | 19.6°C | +2.6°C |
| Avg Low | 8.4°C | 8.7°C | 10.3°C | 10.4°C | 11.1°C | +2.7°C |
| Avg Rain | 98 mm | 102 mm | 85 mm | 109 mm | 67 mm | -31 mm |
September temperatures in Sault Ste. Marie have risen by about 3.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -0.9°C (1993) to a record high of 29°C (2023).
Rainfall in September is a relatively wet time of year, averaging 94 mm, with a wettest year of 208 mm.
One of the best times to visit Sault Ste. Marie
September is one of the best times to visit Sault Ste. Marie. Expect days averaging 18.1°C and nights around 9.7°C (mean 13.9°C) — warmer than Sault Ste. Marie's yearly average — with higher rainfall (94 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 | 19.7°C | 15.6°C | 11.5°C | 25.4°C | 7.2°C | 79 mm | 83% | 1.4 m/s | 3.7 |
| 2024 🔥 | 22.4°C | 17.4°C | 12.5°C | 27.3°C | 6.1°C | 38 mm | 77% | 1.5 m/s | 4.5 |
| 2023 | 20.7°C | 16.1°C | 11.5°C | 29.0°C | 6.3°C | 35 mm | 80% | 1.4 m/s | 4.1 |
| 2022 | 19.3°C | 15.1°C | 10.9°C | 25.1°C | 4.1°C | 60 mm | 81% | 1.5 m/s | 4 |
| 2021 | 18.9°C | 14.8°C | 10.7°C | 23.5°C | 7.5°C | 84 mm | 82% | 1.7 m/s | 3.9 |
| 2020 | 16.4°C | 12.9°C | 9.4°C | 20.6°C | 2.8°C | 106 mm | 84% | 1.8 m/s | 3.5 |
| 2019 | 18.6°C | 14.7°C | 10.8°C | 24.3°C | 6.4°C | 135 mm | 85% | 1.7 m/s | 3.3 |
| 2018 | 19.4°C | 15.1°C | 10.9°C | 26.6°C | 2.5°C | 90 mm | 82% | 1.6 m/s | 3.7 |
| 2017 | 19.8°C | 15.6°C | 11.4°C | 26.8°C | 3.5°C | 42 mm | 83% | 1.3 m/s | 4.1 |
| 2016 | 20.6°C | 16.5°C | 12.4°C | 26.4°C | 8.4°C | 130 mm | 82% | 1.6 m/s | 3.8 |
| 2015 | 20.7°C | 16.6°C | 12.5°C | 25.9°C | 4.7°C | 76 mm | 83% | 1.5 m/s | 4.1 |
| 2014 | 17.3°C | 13.0°C | 8.6°C | 22.3°C | 2.1°C | 117 mm | 86% | 1.5 m/s | 3.7 |
| 2013 | 17.6°C | 13.4°C | 9.1°C | 23.9°C | 3.2°C | 121 mm | 83% | 1.6 m/s | 3.8 |
| 2012 | 18.3°C | 13.9°C | 9.5°C | 28.0°C | 4.1°C | 67 mm | 75% | 1.7 m/s | 3.6 |
| 2011 | 18.7°C | 14.3°C | 9.8°C | 26.1°C | 4.5°C | 107 mm | 79% | 1.6 m/s | 3.8 |
| 2010 🌧️ | 16.4°C | 12.6°C | 8.7°C | 23.4°C | 4.8°C | 208 mm | 83% | 1.9 m/s | 3.5 |
| 2009 | 20.3°C | 15.7°C | 11.1°C | 24.7°C | 2.1°C | 31 mm | 80% | 1.4 m/s | 4.3 |
| 2008 | 18.3°C | 14.2°C | 10.0°C | 26.4°C | 6.4°C | 70 mm | 81% | 1.6 m/s | 3.6 |
| 2007 | 19.3°C | 14.7°C | 10.2°C | 26.7°C | 4.0°C | 130 mm | 79% | 1.7 m/s | 3.5 |
| 2006 | 18.0°C | 13.6°C | 9.3°C | 24.8°C | 3.5°C | 99 mm | 78% | 1.5 m/s | 3.6 |
| 2005 | 20.8°C | 16.3°C | 11.8°C | 27.9°C | 5.3°C | 76 mm | 77% | 1.7 m/s | 4 |
| 2004 | 20.4°C | 16.0°C | 11.6°C | 24.7°C | 6.0°C | 38 mm | 82% | 1.5 m/s | 4.3 |
| 2003 | 17.6°C | 13.7°C | 9.7°C | 23.2°C | 1.4°C | 101 mm | 83% | 1.6 m/s | 3.7 |
| 2002 | 19.3°C | 15.4°C | 11.5°C | 27.1°C | 4.8°C | 74 mm | 85% | 1.5 m/s | 3.6 |
| 2001 | 16.6°C | 12.7°C | 8.9°C | 24.1°C | 2.8°C | 146 mm | 84% | 1.5 m/s | 3.4 |
| 2000 | 17.5°C | 13.3°C | 9.0°C | 23.7°C | 1.6°C | 82 mm | 78% | 1.9 m/s | 3.5 |
| 1999 | 18.5°C | 14.2°C | 9.9°C | 27.5°C | 2.0°C | 80 mm | 78% | 1.6 m/s | 3.8 |
| 1998 | 19.6°C | 15.4°C | 11.2°C | 26.5°C | 5.7°C | 89 mm | 80% | 1.7 m/s | 3.5 |
| 1997 | 17.1°C | 13.2°C | 9.4°C | 21.4°C | 3.0°C | 89 mm | 84% | 1.8 m/s | 3.7 |
| 1996 | 17.3°C | 13.6°C | 9.8°C | 24.8°C | 3.0°C | 157 mm | 86% | 1.3 m/s | 3.5 |
| 1995 | 16.0°C | 11.8°C | 7.6°C | 24.1°C | 1.9°C | 104 mm | 82% | 1.5 m/s | 3.7 |
| 1994 | 18.1°C | 13.9°C | 9.7°C | 23.7°C | 4.8°C | 45 mm | 84% | 1.3 m/s | 3.7 |
| 1993 ❄️ | 14.9°C | 10.5°C | 6.1°C | 21.2°C | -0.9°C | 93 mm | 80% | 1.6 m/s | 3.4 |
| 1992 | 16.0°C | 11.7°C | 7.3°C | 23.0°C | -0.4°C | 129 mm | 81% | 1.6 m/s | 3 |
| 1991 | 15.8°C | 11.8°C | 7.7°C | 24.1°C | -0.8°C | 131 mm | 80% | 1.6 m/s | 3.3 |
| 1990 | 16.7°C | 12.4°C | 8.1°C | 25.0°C | 0.2°C | 105 mm | 83% | 1.4 m/s | 3.6 |
| 1989 | 18.2°C | 13.3°C | 8.4°C | 25.6°C | -0.4°C | 39 mm | 76% | 1.5 m/s | 4.2 |
| 1988 | 17.3°C | 12.9°C | 8.5°C | 24.6°C | 2.3°C | 80 mm | 80% | 1.6 m/s | 3.1 |
| 1987 | 18.5°C | 14.0°C | 9.5°C | 24.2°C | 3.5°C | 78 mm | 80% | 1.4 m/s | 3.7 |
| 1986 | 15.3°C | 11.4°C | 7.6°C | 22.7°C | 2.0°C | 147 mm | 85% | 1.4 m/s | 2.9 |
| 1985 | 16.8°C | 12.9°C | 8.9°C | 23.8°C | 2.3°C | 95 mm | 85% | 1.3 m/s | 3 |
| 1984 | 15.3°C | 11.1°C | 6.9°C | 20.4°C | 0.1°C | 140 mm | 82% | 1.5 m/s | 3.4 |
| 1983 | 18.2°C | 14.1°C | 9.9°C | 26.2°C | 2.7°C | 102 mm | 82% | 1.4 m/s | — |
| 1982 | 15.9°C | 11.8°C | 7.8°C | 24.0°C | 4.4°C | 146 mm | 86% | 1.3 m/s | — |
| 1981 | 17.2°C | 12.5°C | 7.8°C | 24.4°C | 1.8°C | 50 mm | 76% | 1.6 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 18.1°C with lows near 9.7°C (mean 13.9°C), based on 45 years of NASA POWER data.
September averages 94 mm of rainfall in Sault Ste. Marie, a relatively wet time of year. The wettest on record was 208 mm in 2010.
The hottest September reached 29°C in 2023. The coldest dipped to -0.9°C in 1993.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 3.3°C. Daytime highs moved from 16.7°C to 20.2°C and overnight lows from 8.3°C to 11.4°C over the same span.
September is one of the warmer months of the year in Sault Ste. Marie and a relatively wet time of year, so plan for around 18.1°C daytime highs and 9.7°C at night.
Not quite — September is the 10th coolest month in Sault Ste. Marie, averaging 13.9°C.
For September in Sault Ste. Marie, pack light layers you can adjust through the day, with typical highs of 18.1°C and lows of 9.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 81% — quite humid.
Average wind speed in September is 1.5 m/s. The windiest September on record averaged 1.9 m/s (2000).
The wettest September on record was 2010 with 208 mm. On average, September sees 94 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 Sault Ste. Marie 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.
