September is one of the warmer months of the year in North Bay, with average highs near 18.7°C and lows around 8.9°C (mean 13.8°C). It is a relatively wet time of year, averaging 88 mm of rainfall and 79% relative humidity across the period.
September is one of the warmer months of the year in North Bay. Across 45 years of records, the warmest September in North Bay was 2024 — when the month averaged 17.5°C — while the coldest was 1995 at 10.9°C. Typical September days reach 18.7°C with nights near 8.9°C. The long-term trend is warming, about 0.8°C per decade.
September is a relatively wet time of year in North Bay, averaging 88 mm of rainfall. The wettest September on record was 2001 with 176 mm, while the driest was 2004 at 35 mm.
Relative humidity in North Bay during September averages 79%. The most humid September was 2001 at 85%, and the least humid was 2024 at 72%.
September receives about 3.6 kWh/m²/day of solar energy in North Bay. The sunniest September was 2009 at 4.3 kWh/m²/day, and the cloudiest was 2010 at 2.8.
Average wind speed in North Bay during September is 0.6 m/s. The windiest Septembers were 2000, 2020 and 2021 at 0.7 m/s, while the calmest were 1994, 2023 and 2025, among others at 0.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.9°C | 12.8°C | 13.9°C | 14.8°C | 15.3°C | +2.4°C |
| Avg High | 17.6°C | 17.6°C | 18.7°C | 19.8°C | 20.7°C | +3.1°C |
| Avg Low | 8.3°C | 7.9°C | 9.1°C | 9.7°C | 9.9°C | +1.6°C |
| Avg Rain | 102 mm | 111 mm | 87 mm | 72 mm | 56 mm | -46 mm |
September temperatures in North Bay have risen by about 2.8°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -2.8°C (1981) to a record high of 30.7°C (2023).
Rainfall in September is a relatively wet time of year, averaging 88 mm, with a wettest year of 176 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.9°C per decade while lows rose 0.6°C per decade, widening the gap between day and night.
One of the best times to visit North Bay
September is one of the best times to visit North Bay. Expect days averaging 18.7°C and nights around 8.9°C (mean 13.8°C) — warmer than North Bay's yearly average — with higher rainfall (88 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 | 20.6°C | 15.1°C | 9.5°C | 25.4°C | 2.8°C | 36 mm | 73% | 0.5 m/s | 4.2 |
| 2024 🔥 | 23.3°C | 17.5°C | 11.7°C | 29.1°C | 5.6°C | 56 mm | 72% | 0.6 m/s | 4 |
| 2023 | 22.0°C | 16.3°C | 10.6°C | 30.7°C | 5.3°C | 38 mm | 73% | 0.5 m/s | 4.2 |
| 2022 | 20.0°C | 14.8°C | 9.5°C | 27.4°C | 2.1°C | 79 mm | 76% | 0.6 m/s | 3.5 |
| 2021 | 19.9°C | 14.8°C | 9.7°C | 25.1°C | 4.0°C | 55 mm | 74% | 0.7 m/s | 3.5 |
| 2020 | 18.1°C | 13.3°C | 8.6°C | 24.1°C | 2.5°C | 73 mm | 75% | 0.7 m/s | 3.4 |
| 2019 | 19.2°C | 14.3°C | 9.4°C | 25.9°C | 3.4°C | 92 mm | 78% | 0.6 m/s | 3.3 |
| 2018 | 20.6°C | 15.5°C | 10.3°C | 29.2°C | 2.7°C | 70 mm | 74% | 0.6 m/s | 3.7 |
| 2017 | 21.0°C | 16.0°C | 10.9°C | 28.9°C | 4.0°C | 51 mm | 78% | 0.6 m/s | 3.9 |
| 2016 | 21.4°C | 16.2°C | 11.0°C | 29.3°C | 4.3°C | 64 mm | 74% | 0.6 m/s | 3.9 |
| 2015 | 22.5°C | 17.1°C | 11.8°C | 29.4°C | 4.7°C | 46 mm | 76% | 0.6 m/s | 3.8 |
| 2014 | 18.3°C | 13.4°C | 8.5°C | 25.4°C | -0.5°C | 73 mm | 81% | 0.6 m/s | 3.3 |
| 2013 | 19.3°C | 13.8°C | 8.3°C | 24.6°C | 1.4°C | 79 mm | 74% | 0.6 m/s | 3.7 |
| 2012 | 18.5°C | 13.7°C | 8.9°C | 26.7°C | 3.2°C | 68 mm | 74% | 0.6 m/s | 3.6 |
| 2011 | 20.1°C | 14.7°C | 9.2°C | 29.6°C | 1.1°C | 52 mm | 75% | 0.6 m/s | 3.7 |
| 2010 | 17.4°C | 13.2°C | 9.0°C | 30.3°C | 3.1°C | 123 mm | 81% | 0.6 m/s | 2.8 |
| 2009 | 19.2°C | 13.9°C | 8.6°C | 23.4°C | 1.2°C | 39 mm | 76% | 0.6 m/s | 4.3 |
| 2008 | 18.5°C | 13.3°C | 8.2°C | 26.0°C | 3.1°C | 71 mm | 79% | 0.6 m/s | 3.8 |
| 2007 | 19.6°C | 14.6°C | 9.5°C | 27.0°C | 4.2°C | 45 mm | 77% | 0.6 m/s | 4.1 |
| 2006 | 16.7°C | 11.9°C | 7.1°C | 23.6°C | 2.1°C | 107 mm | 82% | 0.6 m/s | 3.2 |
| 2005 | 20.9°C | 15.7°C | 10.6°C | 27.9°C | 3.4°C | 99 mm | 77% | 0.6 m/s | 4 |
| 2004 | 20.0°C | 15.0°C | 10.0°C | 24.3°C | 3.6°C | 35 mm | 82% | 0.6 m/s | 4.1 |
| 2003 | 18.7°C | 14.3°C | 10.0°C | 25.6°C | 1.5°C | 111 mm | 83% | 0.6 m/s | 3.6 |
| 2002 | 20.3°C | 15.6°C | 10.9°C | 27.3°C | 6.0°C | 107 mm | 82% | 0.6 m/s | 3.9 |
| 2001 🌧️ | 17.1°C | 13.0°C | 9.0°C | 25.7°C | 3.1°C | 176 mm | 85% | 0.6 m/s | 3.2 |
| 2000 | 16.5°C | 11.8°C | 7.1°C | 24.5°C | -2.6°C | 79 mm | 81% | 0.7 m/s | 3.3 |
| 1999 | 20.0°C | 15.0°C | 9.9°C | 29.1°C | 1.6°C | 151 mm | 77% | 0.6 m/s | 3.5 |
| 1998 | 19.0°C | 14.1°C | 9.3°C | 25.8°C | 4.2°C | 98 mm | 77% | 0.6 m/s | 3.6 |
| 1997 | 17.3°C | 12.7°C | 8.1°C | 22.3°C | 0.1°C | 85 mm | 80% | 0.6 m/s | 3.2 |
| 1996 | 18.7°C | 14.2°C | 9.8°C | 26.2°C | 2.9°C | 102 mm | 83% | 0.6 m/s | 3.5 |
| 1995 ❄️ | 16.2°C | 10.9°C | 5.6°C | 21.0°C | 0.3°C | 91 mm | 79% | 0.6 m/s | 3.6 |
| 1994 | 18.2°C | 13.5°C | 8.8°C | 24.2°C | 2.9°C | 84 mm | 82% | 0.5 m/s | 3.7 |
| 1993 | 16.0°C | 11.0°C | 6.1°C | 24.5°C | -1.4°C | 106 mm | 78% | 0.6 m/s | 3.3 |
| 1992 | 17.7°C | 12.7°C | 7.6°C | 23.8°C | -0.4°C | 143 mm | 80% | 0.6 m/s | 3.3 |
| 1991 | 16.4°C | 11.7°C | 7.0°C | 24.8°C | -1.9°C | 121 mm | 79% | 0.6 m/s | 3.5 |
| 1990 | 16.4°C | 11.8°C | 7.2°C | 25.4°C | 0.8°C | 125 mm | 82% | 0.6 m/s | 3.1 |
| 1989 | 18.5°C | 13.4°C | 8.3°C | 25.0°C | -2.5°C | 60 mm | 77% | 0.6 m/s | 3.6 |
| 1988 | 18.2°C | 13.0°C | 7.7°C | 24.5°C | 1.5°C | 106 mm | 79% | 0.6 m/s | 3.7 |
| 1987 | 18.4°C | 14.0°C | 9.5°C | 24.7°C | 1.8°C | 68 mm | 79% | 0.5 m/s | 3.4 |
| 1986 | 16.1°C | 11.6°C | 7.1°C | 23.0°C | 0.7°C | 115 mm | 82% | 0.6 m/s | 3.5 |
| 1985 | 18.1°C | 13.5°C | 9.0°C | 25.9°C | 3.4°C | 79 mm | 82% | 0.6 m/s | 3.6 |
| 1984 | 16.0°C | 11.5°C | 7.1°C | 23.5°C | 0.9°C | 111 mm | 81% | 0.6 m/s | 3.7 |
| 1983 | 19.0°C | 14.5°C | 9.9°C | 27.1°C | 3.9°C | 121 mm | 81% | 0.6 m/s | — |
| 1982 | 17.5°C | 12.8°C | 8.2°C | 25.7°C | 2.3°C | 129 mm | 83% | 0.5 m/s | — |
| 1981 | 16.3°C | 12.1°C | 8.0°C | 25.3°C | -2.8°C | 133 mm | 83% | 0.6 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 18.7°C with lows near 8.9°C (mean 13.8°C), based on 45 years of NASA POWER data.
September averages 88 mm of rainfall in North Bay, a relatively wet time of year. The wettest on record was 176 mm in 2001.
The hottest September reached 30.7°C in 2023. The coldest dipped to -2.8°C in 1981.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 2.8°C. Daytime highs moved from 17.4°C to 21.2°C and overnight lows from 8.4°C to 10.2°C over the same span.
September is one of the warmer months of the year in North Bay and a relatively wet time of year, so plan for around 18.7°C daytime highs and 8.9°C at night.
Not quite — September is the 9th coolest month in North Bay, averaging 13.8°C.
For September in North Bay, pack light layers you can adjust through the day, with typical highs of 18.7°C and lows of 8.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 79% — quite humid.
Average wind speed in September is 0.6 m/s. The windiest September on record averaged 0.7 m/s (2000).
The wettest September on record was 2001 with 176 mm. On average, September sees 88 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 North Bay 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.
