September is one of the warmer months of the year in Penticton, with average highs near 17.8°C and lows around 4.7°C (mean 11.3°C). It is one of the drier months, averaging 34 mm of rainfall and 66% relative humidity across the period.
September is one of the warmer months of the year in Penticton. Across 45 years of records, the warmest September in Penticton was 2025 — when the month averaged 14.7°C — while the coldest was 1985 at 7.3°C. Typical September days reach 17.8°C with nights near 4.7°C. The long-term trend is warming, about 0.5°C per decade.
September is one of the drier months in Penticton, averaging 34 mm of rainfall. The wettest September on record was 2019 with 89 mm, while the driest was 1991 at 5 mm.
Relative humidity in Penticton during September averages 66%. The most humid September was 2019 at 77%, and the least humid was 1987 at 53%.
September receives about 4.1 kWh/m²/day of solar energy in Penticton. The sunniest September was 1990 at 4.8 kWh/m²/day, and the cloudiest was 2019 at 3.1.
Average wind speed in Penticton during September is 0.3 m/s. The windiest Septembers were 2008, 2012 and 2014, among others at 0.4 m/s, while the calmest were 2023, 2024 and 2025, among others at 0.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.9°C | 11.8°C | 11.0°C | 11.1°C | 12.9°C | +3°C |
| Avg High | 16.2°C | 18.7°C | 17.8°C | 17.3°C | 19.3°C | +3.1°C |
| Avg Low | 3.5°C | 4.9°C | 4.2°C | 4.9°C | 6.6°C | +3.1°C |
| Avg Rain | 40 mm | 25 mm | 30 mm | 43 mm | 30 mm | -10 mm |
September temperatures in Penticton have risen by about 4°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -5.7°C (1983) to a record high of 33.3°C (1988).
Rainfall in September is one of the drier months, averaging 34 mm, with a wettest year of 89 mm.
One of the best times to visit Penticton
September is one of the best times to visit Penticton. Expect days averaging 17.8°C and nights around 4.7°C (mean 11.3°C) — warmer than Penticton's yearly average — with moderate rainfall (34 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 🔥 | 20.9°C | 14.7°C | 8.5°C | 31.1°C | 4.2°C | 33 mm | 73% | 0.3 m/s | 4 |
| 2024 | 19.4°C | 13.1°C | 6.9°C | 30.8°C | -1.5°C | 26 mm | 67% | 0.3 m/s | 4.1 |
| 2023 | 17.7°C | 11.5°C | 5.2°C | 25.5°C | -0.8°C | 39 mm | 69% | 0.3 m/s | 3.8 |
| 2022 | 20.4°C | 13.5°C | 6.5°C | 30.5°C | 0.5°C | 18 mm | 63% | 0.3 m/s | 4.1 |
| 2021 | 17.3°C | 11.2°C | 5.2°C | 26.3°C | -0.4°C | 41 mm | 68% | 0.3 m/s | 3.5 |
| 2020 | 20.1°C | 13.6°C | 7.2°C | 27.6°C | 1.3°C | 24 mm | 67% | 0.3 m/s | 3.9 |
| 2019 🌧️ | 15.1°C | 10.1°C | 5.2°C | 26.0°C | -5.5°C | 89 mm | 77% | 0.3 m/s | 3.1 |
| 2018 | 14.7°C | 9.2°C | 3.7°C | 23.2°C | -0.6°C | 52 mm | 74% | 0.3 m/s | 3.7 |
| 2017 | 18.3°C | 12.1°C | 5.8°C | 28.6°C | 0.4°C | 20 mm | 67% | 0.3 m/s | 3.8 |
| 2016 | 15.7°C | 9.7°C | 3.7°C | 22.6°C | -0.3°C | 43 mm | 74% | 0.3 m/s | 3.8 |
| 2015 | 15.9°C | 9.7°C | 3.6°C | 27.5°C | -1.7°C | 32 mm | 66% | 0.3 m/s | 3.9 |
| 2014 | 18.4°C | 12.0°C | 5.7°C | 25.6°C | -1.1°C | 40 mm | 66% | 0.4 m/s | 4.1 |
| 2013 | 17.6°C | 11.8°C | 6.1°C | 28.0°C | -3.4°C | 76 mm | 75% | 0.3 m/s | 3.6 |
| 2012 | 21.0°C | 13.2°C | 5.4°C | 27.0°C | 0.7°C | 10 mm | 56% | 0.4 m/s | 4.7 |
| 2011 | 20.8°C | 13.4°C | 5.9°C | 29.2°C | 0.7°C | 12 mm | 57% | 0.3 m/s | 4.5 |
| 2010 | 15.6°C | 9.8°C | 3.9°C | 24.0°C | -1.8°C | 53 mm | 76% | 0.3 m/s | 3.4 |
| 2009 | 20.1°C | 12.9°C | 5.7°C | 29.5°C | -1.2°C | 32 mm | 59% | 0.3 m/s | 4.5 |
| 2008 | 18.6°C | 11.3°C | 4.1°C | 27.2°C | -0.3°C | 20 mm | 58% | 0.4 m/s | 4.2 |
| 2007 | 16.4°C | 10.0°C | 3.6°C | 26.8°C | -1.3°C | 38 mm | 67% | 0.3 m/s | 4 |
| 2006 | 19.6°C | 12.4°C | 5.3°C | 29.5°C | -2.5°C | 21 mm | 62% | 0.4 m/s | 4.2 |
| 2005 | 15.5°C | 9.2°C | 2.8°C | 22.7°C | -4.1°C | 32 mm | 71% | 0.3 m/s | 4 |
| 2004 | 15.0°C | 9.3°C | 3.6°C | 22.2°C | -2.6°C | 53 mm | 75% | 0.3 m/s | 3.6 |
| 2003 | 19.3°C | 12.1°C | 5.0°C | 30.6°C | -0.5°C | 20 mm | 59% | 0.3 m/s | 4.2 |
| 2002 | 17.6°C | 10.5°C | 3.4°C | 26.5°C | -1.2°C | 26 mm | 64% | 0.3 m/s | 4.1 |
| 2001 | 19.7°C | 12.3°C | 4.9°C | 27.2°C | 0.2°C | 24 mm | 58% | 0.4 m/s | 4.5 |
| 2000 | 16.3°C | 10.1°C | 3.8°C | 25.9°C | -5.2°C | 39 mm | 66% | 0.3 m/s | 3.8 |
| 1999 | 17.7°C | 10.5°C | 3.4°C | 25.6°C | -2.4°C | 14 mm | 59% | 0.4 m/s | 4.4 |
| 1998 | 21.8°C | 14.4°C | 7.1°C | 29.1°C | 0.3°C | 14 mm | 58% | 0.4 m/s | 4.7 |
| 1997 | 17.9°C | 11.7°C | 5.4°C | 25.2°C | -2.0°C | 62 mm | 70% | 0.3 m/s | 4 |
| 1996 | 15.2°C | 8.9°C | 2.7°C | 27.0°C | -2.7°C | 49 mm | 70% | 0.4 m/s | 3.6 |
| 1995 | 20.2°C | 13.1°C | 6.0°C | 27.6°C | -0.4°C | 24 mm | 58% | 0.4 m/s | 4.5 |
| 1994 | 20.6°C | 13.6°C | 6.5°C | 26.8°C | 2.3°C | 23 mm | 58% | 0.4 m/s | 4.3 |
| 1993 | 18.2°C | 11.4°C | 4.6°C | 25.4°C | -2.0°C | 23 mm | 61% | 0.4 m/s | 4.7 |
| 1992 | 15.4°C | 8.9°C | 2.5°C | 22.4°C | -5.0°C | 25 mm | 66% | 0.3 m/s | 3.9 |
| 1991 | 19.1°C | 11.9°C | 4.7°C | 25.2°C | -0.3°C | 5 mm | 63% | 0.4 m/s | 4.7 |
| 1990 | 21.0°C | 13.3°C | 5.6°C | 25.4°C | 0.7°C | 11 mm | 60% | 0.4 m/s | 4.8 |
| 1989 | 18.6°C | 11.5°C | 4.4°C | 24.0°C | -1.7°C | 29 mm | 63% | 0.4 m/s | 4.6 |
| 1988 | 18.0°C | 11.1°C | 4.1°C | 33.3°C | -1.5°C | 38 mm | 64% | 0.3 m/s | 3.7 |
| 1987 | 21.6°C | 13.9°C | 6.3°C | 29.3°C | 1.1°C | 11 mm | 53% | 0.4 m/s | 4.7 |
| 1986 | 13.4°C | 8.1°C | 2.8°C | 23.4°C | -1.9°C | 69 mm | 73% | 0.3 m/s | 3.4 |
| 1985 ❄️ | 13.1°C | 7.3°C | 1.5°C | 19.4°C | -3.8°C | 66 mm | 70% | 0.3 m/s | 3.6 |
| 1984 | 14.2°C | 8.1°C | 2.0°C | 22.1°C | -3.8°C | 26 mm | 67% | 0.3 m/s | 3.8 |
| 1983 | 13.6°C | 7.7°C | 1.8°C | 19.0°C | -5.7°C | 37 mm | 72% | 0.3 m/s | — |
| 1982 | 16.1°C | 10.3°C | 4.5°C | 24.8°C | -0.9°C | 47 mm | 74% | 0.3 m/s | — |
| 1981 | 17.0°C | 10.7°C | 4.4°C | 28.5°C | -3.4°C | 35 mm | 67% | 0.3 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 17.8°C with lows near 4.7°C (mean 11.3°C), based on 45 years of NASA POWER data.
September averages 34 mm of rainfall in Penticton, one of the drier months. The wettest on record was 89 mm in 2019.
The hottest September reached 33.3°C in 1988. The coldest dipped to -5.7°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 4°C. Daytime highs moved from 14.8°C to 19.1°C and overnight lows from 2.8°C to 6.5°C over the same span.
September is one of the warmer months of the year in Penticton and one of the drier months, so plan for around 17.8°C daytime highs and 4.7°C at night.
Not quite — September is the 9th coolest month in Penticton, averaging 11.3°C.
For September in Penticton, pack warm layers and a jacket for chilly mornings, with typical highs of 17.8°C and lows of 4.7°C.
Relative humidity in September averages 66% — moderately humid.
Average wind speed in September is 0.3 m/s. The windiest September on record averaged 0.4 m/s (1987).
The wettest September on record was 2019 with 89 mm. On average, September sees 34 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 Penticton 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.
