September is one of the warmer months of the year in Kawartha Lakes, with average highs near 22°C and lows around 10.9°C (mean 16.5°C). It is a relatively wet time of year, averaging 60 mm of rainfall and 70% relative humidity across the period.
September is one of the warmer months of the year in Kawartha Lakes. Across 45 years of records, the warmest September in Kawartha Lakes was 2015 — when the month averaged 19.5°C — while the coldest was 1993 at 13°C. Typical September days reach 22°C with nights near 10.9°C. The long-term trend is warming, about 0.9°C per decade.
September is a relatively wet time of year in Kawartha Lakes, averaging 60 mm of rainfall. The wettest September on record was 1993 with 119 mm, while the driest was 2023 at 7 mm.
Relative humidity in Kawartha Lakes during September averages 70%. The most humid September was 1981 at 82%, and the least humid was 2025 at 62%.
September receives about 4 kWh/m²/day of solar energy in Kawartha Lakes. The sunniest Septembers were 2004, 2009 and 2023 at 4.6 kWh/m²/day, and the cloudiest was 2006 at 3.2.
Average wind speed in Kawartha Lakes during September is 1.8 m/s. The windiest Septembers were 1988, 2010 and 2021 at 2.1 m/s, while the calmest were 2017, 2023 and 2025, among others at 1.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 15.1°C | 15.2°C | 16.8°C | 17.5°C | 18.0°C | +2.9°C |
| Avg High | 20.6°C | 20.7°C | 22.4°C | 23.0°C | 23.7°C | +3.1°C |
| Avg Low | 9.7°C | 9.7°C | 11.1°C | 11.9°C | 12.3°C | +2.6°C |
| Avg Rain | 77 mm | 73 mm | 54 mm | 50 mm | 39 mm | -38 mm |
September temperatures in Kawartha Lakes have risen by about 3.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -1.6°C (1981) to a record high of 33.6°C (2002).
Rainfall in September is a relatively wet time of year, averaging 60 mm, with a wettest year of 119 mm.
One of the best times to visit Kawartha Lakes
September is one of the best times to visit Kawartha Lakes. Expect days averaging 22°C and nights around 10.9°C (mean 16.5°C) — warmer than Kawartha Lakes's yearly average — with moderate rainfall (60 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 | 24.4°C | 18.4°C | 12.4°C | 28.5°C | 6.8°C | 28 mm | 62% | 1.5 m/s | 4.4 |
| 2024 | 25.2°C | 19.3°C | 13.4°C | 29.7°C | 6.7°C | 63 mm | 68% | 1.6 m/s | 4.2 |
| 2023 | 24.9°C | 18.8°C | 12.7°C | 33.4°C | 6.8°C | 7 mm | 64% | 1.5 m/s | 4.6 |
| 2022 | 22.3°C | 16.9°C | 11.6°C | 30.8°C | 3.4°C | 40 mm | 70% | 1.7 m/s | 3.8 |
| 2021 | 23.2°C | 17.8°C | 12.4°C | 26.8°C | 6.4°C | 67 mm | 68% | 2.1 m/s | 4 |
| 2020 | 22.0°C | 16.5°C | 11.1°C | 27.7°C | 3.6°C | 27 mm | 69% | 2 m/s | 4 |
| 2019 | 22.8°C | 17.3°C | 11.7°C | 28.1°C | 6.9°C | 49 mm | 71% | 1.9 m/s | 3.8 |
| 2018 | 24.0°C | 18.6°C | 13.1°C | 32.8°C | 6.7°C | 44 mm | 69% | 1.9 m/s | 4.1 |
| 2017 | 24.7°C | 18.8°C | 13.0°C | 33.0°C | 4.5°C | 37 mm | 68% | 1.5 m/s | 4.4 |
| 2016 | 24.7°C | 18.9°C | 13.0°C | 31.5°C | 5.4°C | 39 mm | 64% | 1.8 m/s | 4.5 |
| 2015 🔥 | 25.1°C | 19.5°C | 13.9°C | 32.2°C | 6.6°C | 63 mm | 69% | 1.7 m/s | 4.2 |
| 2014 | 21.9°C | 16.2°C | 10.4°C | 28.8°C | 2.1°C | 59 mm | 72% | 1.8 m/s | 4.1 |
| 2013 | 21.8°C | 15.9°C | 10.0°C | 32.2°C | 3.1°C | 54 mm | 69% | 1.8 m/s | 4.2 |
| 2012 | 21.5°C | 16.1°C | 10.7°C | 29.1°C | 4.7°C | 50 mm | 68% | 1.8 m/s | 4 |
| 2011 | 22.8°C | 17.5°C | 12.2°C | 30.4°C | 3.4°C | 52 mm | 70% | 1.7 m/s | 3.8 |
| 2010 | 21.1°C | 16.2°C | 11.2°C | 32.8°C | 5.7°C | 55 mm | 72% | 2.1 m/s | 3.4 |
| 2009 | 22.5°C | 16.6°C | 10.7°C | 27.5°C | 2.6°C | 34 mm | 68% | 1.7 m/s | 4.6 |
| 2008 | 22.5°C | 16.8°C | 11.0°C | 31.5°C | 5.6°C | 52 mm | 71% | 1.5 m/s | 3.9 |
| 2007 | 23.0°C | 17.2°C | 11.4°C | 31.5°C | 4.9°C | 58 mm | 68% | 1.8 m/s | 4.5 |
| 2006 | 20.1°C | 15.1°C | 10.0°C | 26.2°C | 2.9°C | 77 mm | 74% | 1.9 m/s | 3.2 |
| 2005 | 24.8°C | 18.8°C | 12.7°C | 31.0°C | 6.4°C | 42 mm | 66% | 2 m/s | 4.5 |
| 2004 | 23.4°C | 17.4°C | 11.4°C | 28.9°C | 4.0°C | 35 mm | 72% | 1.7 m/s | 4.6 |
| 2003 | 21.9°C | 16.6°C | 11.3°C | 29.4°C | 4.8°C | 64 mm | 70% | 2 m/s | 3.9 |
| 2002 | 24.6°C | 18.9°C | 13.3°C | 33.6°C | 7.7°C | 37 mm | 67% | 1.8 m/s | 4.3 |
| 2001 | 20.8°C | 15.5°C | 10.2°C | 29.2°C | 4.3°C | 71 mm | 73% | 1.9 m/s | 4.1 |
| 2000 | 20.4°C | 14.8°C | 9.3°C | 30.9°C | -0.9°C | 70 mm | 72% | 1.9 m/s | 4 |
| 1999 | 23.1°C | 17.4°C | 11.8°C | 32.1°C | 2.3°C | 71 mm | 68% | 1.8 m/s | 3.9 |
| 1998 | 22.3°C | 16.8°C | 11.2°C | 28.3°C | 3.7°C | 61 mm | 71% | 1.7 m/s | 4.2 |
| 1997 | 20.6°C | 15.0°C | 9.5°C | 25.9°C | 2.1°C | 61 mm | 72% | 2 m/s | 3.8 |
| 1996 | 21.3°C | 16.3°C | 11.2°C | 30.6°C | 3.8°C | 86 mm | 73% | 1.8 m/s | 3.5 |
| 1995 | 19.6°C | 13.7°C | 7.8°C | 27.2°C | 3.3°C | 58 mm | 68% | 1.7 m/s | 4.1 |
| 1994 | 21.5°C | 15.8°C | 10.0°C | 29.4°C | 4.3°C | 32 mm | 71% | 1.8 m/s | 3.9 |
| 1993 ❄️ 🌧️ | 18.1°C | 13.0°C | 8.0°C | 28.0°C | -0.2°C | 119 mm | 75% | 1.9 m/s | 3.4 |
| 1992 | 19.4°C | 14.1°C | 8.8°C | 25.7°C | 0.7°C | 107 mm | 78% | 2 m/s | 3.8 |
| 1991 | 20.2°C | 14.7°C | 9.2°C | 30.1°C | -1.1°C | 50 mm | 66% | 1.9 m/s | 3.9 |
| 1990 | 20.4°C | 14.9°C | 9.3°C | 28.1°C | 2.1°C | 84 mm | 73% | 1.8 m/s | 3.4 |
| 1989 | 21.4°C | 15.7°C | 10.1°C | 28.2°C | -1.2°C | 85 mm | 70% | 1.8 m/s | 3.9 |
| 1988 | 21.5°C | 15.5°C | 9.6°C | 27.9°C | 3.4°C | 48 mm | 67% | 2.1 m/s | 4.2 |
| 1987 | 21.3°C | 16.0°C | 10.7°C | 28.3°C | 4.0°C | 41 mm | 71% | 1.8 m/s | 3.7 |
| 1986 | 19.6°C | 14.3°C | 9.0°C | 27.1°C | 1.5°C | 92 mm | 75% | 1.8 m/s | 3.5 |
| 1985 | 21.3°C | 15.8°C | 10.4°C | 28.2°C | 3.3°C | 77 mm | 76% | 1.7 m/s | 4 |
| 1984 | 18.9°C | 13.6°C | 8.2°C | 26.1°C | 0.6°C | 97 mm | 74% | 1.8 m/s | 4 |
| 1983 | 22.7°C | 16.8°C | 10.9°C | 31.2°C | 4.7°C | 56 mm | 67% | 1.9 m/s | — |
| 1982 | 20.4°C | 14.8°C | 9.2°C | 29.1°C | 4.0°C | 82 mm | 73% | 1.6 m/s | — |
| 1981 | 18.0°C | 13.7°C | 9.5°C | 26.4°C | -1.6°C | 116 mm | 82% | 1.9 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 22°C with lows near 10.9°C (mean 16.5°C), based on 45 years of NASA POWER data.
September averages 60 mm of rainfall in Kawartha Lakes, a relatively wet time of year. The wettest on record was 119 mm in 1993.
The hottest September reached 33.6°C in 2002. The coldest dipped to -1.6°C in 1981.
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 20.3°C to 24°C and overnight lows from 9.6°C to 12.5°C over the same span.
September is one of the warmer months of the year in Kawartha Lakes and a relatively wet time of year, so plan for around 22°C daytime highs and 10.9°C at night.
Not quite — September is the 9th coolest month in Kawartha Lakes, averaging 16.5°C.
For September in Kawartha Lakes, pack light layers you can adjust through the day, with typical highs of 22°C and lows of 10.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 70% — moderately humid.
Average wind speed in September is 1.8 m/s. The windiest September on record averaged 2.1 m/s (1988).
The wettest September on record was 1993 with 119 mm. On average, September sees 60 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 Kawartha Lakes 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.
