September is one of the warmer months of the year in Portage La Prairie, with average highs near 19.9°C and lows around 8.5°C (mean 14.2°C). It is about average for rainfall, averaging 51 mm of rainfall and 66% relative humidity across the period.
September is one of the warmer months of the year in Portage La Prairie. Across 45 years of records, the warmest September in Portage La Prairie was 2024 — when the month averaged 18.9°C — while the coldest was 1985 at 10°C. Typical September days reach 19.9°C with nights near 8.5°C. The long-term trend is warming, about 0.8°C per decade.
September is about average for rainfall in Portage La Prairie, averaging 51 mm of rainfall. The wettest September on record was 2019 with 145 mm, while the driest was 1997 at 15 mm.
Relative humidity in Portage La Prairie during September averages 66%. The most humid September was 2019 at 76%, and the least humid was 2012 at 55%.
September receives about 3.8 kWh/m²/day of solar energy in Portage La Prairie. The sunniest September was 1989 at 4.4 kWh/m²/day, and the cloudiest were 1986 and 2019 at 3.2.
Average wind speed in Portage La Prairie during September is 3.6 m/s. The windiest September was 1988 at 4 m/s, while the calmest was 2001 at 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 | 13.9°C | 14.4°C | 14.2°C | 16.6°C | +3.9°C |
| Avg High | 18.2°C | 19.7°C | 20.1°C | 19.9°C | 22.3°C | +4.1°C |
| Avg Low | 7.3°C | 8.1°C | 8.7°C | 8.5°C | 10.8°C | +3.5°C |
| Avg Rain | 61 mm | 37 mm | 49 mm | 65 mm | 39 mm | -21 mm |
September temperatures in Portage La Prairie have risen by about 5.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -3.7°C (2018) to a record high of 35.3°C (2023).
Rainfall in September is about average for rainfall, averaging 51 mm, with a wettest year of 145 mm.
One of the best times to visit Portage La Prairie
September is one of the best times to visit Portage La Prairie. Expect days averaging 19.9°C and nights around 8.5°C (mean 14.2°C) — warmer than Portage La Prairie's yearly average — with moderate rainfall (51 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 | 23.4°C | 17.8°C | 12.3°C | 30.6°C | 4.1°C | 38 mm | 69% | 3.3 m/s | 3.3 |
| 2024 🔥 | 24.8°C | 18.9°C | 13.1°C | 30.9°C | 7.0°C | 38 mm | 66% | 3.7 m/s | 4 |
| 2023 | 23.0°C | 17.5°C | 12.1°C | 35.3°C | 5.9°C | 51 mm | 67% | 3.2 m/s | 3.6 |
| 2022 | 20.9°C | 15.4°C | 9.8°C | 31.2°C | 3.2°C | 56 mm | 67% | 3.5 m/s | 4.1 |
| 2021 | 22.8°C | 16.7°C | 10.6°C | 29.0°C | 6.5°C | 28 mm | 63% | 3.6 m/s | 4.1 |
| 2020 | 19.0°C | 13.0°C | 7.0°C | 28.5°C | 0.8°C | 26 mm | 64% | 3.9 m/s | 3.8 |
| 2019 🌧️ | 19.0°C | 14.0°C | 8.9°C | 28.6°C | 1.0°C | 145 mm | 76% | 3.3 m/s | 3.2 |
| 2018 | 17.1°C | 11.7°C | 6.4°C | 28.4°C | -3.7°C | 69 mm | 67% | 3.5 m/s | 3.4 |
| 2017 | 19.9°C | 14.6°C | 9.3°C | 31.6°C | 4.2°C | 87 mm | 69% | 3.9 m/s | 3.6 |
| 2016 | 20.4°C | 14.8°C | 9.2°C | 28.2°C | 3.9°C | 67 mm | 71% | 3.7 m/s | 3.6 |
| 2015 | 22.7°C | 16.5°C | 10.3°C | 33.5°C | 2.1°C | 63 mm | 65% | 3.7 m/s | 4 |
| 2014 | 19.6°C | 13.6°C | 7.7°C | 28.9°C | 1.3°C | 45 mm | 71% | 3.6 m/s | 3.7 |
| 2013 | 22.1°C | 16.0°C | 9.9°C | 29.8°C | 3.7°C | 41 mm | 67% | 3.4 m/s | 3.8 |
| 2012 | 20.0°C | 13.9°C | 7.8°C | 30.4°C | -0.2°C | 17 mm | 55% | 3.7 m/s | 4.1 |
| 2011 | 20.9°C | 14.8°C | 8.6°C | 30.5°C | 1.4°C | 41 mm | 64% | 3.8 m/s | 4.3 |
| 2010 | 16.8°C | 11.9°C | 7.0°C | 23.7°C | 0.7°C | 80 mm | 75% | 3.7 m/s | 3.5 |
| 2009 | 24.1°C | 18.1°C | 12.1°C | 29.5°C | 1.2°C | 36 mm | 70% | 3.4 m/s | 4.3 |
| 2008 | 18.6°C | 13.5°C | 8.3°C | 27.1°C | 3.3°C | 76 mm | 72% | 3.4 m/s | 3.8 |
| 2007 | 19.8°C | 13.8°C | 7.8°C | 32.1°C | 0.8°C | 45 mm | 67% | 3.7 m/s | 3.7 |
| 2006 | 20.0°C | 14.1°C | 8.1°C | 29.8°C | 1.0°C | 62 mm | 64% | 3.3 m/s | 4.1 |
| 2005 | 20.7°C | 14.9°C | 9.0°C | 28.2°C | 3.8°C | 27 mm | 69% | 3.4 m/s | 4.2 |
| 2004 | 20.5°C | 14.9°C | 9.3°C | 30.0°C | 4.9°C | 49 mm | 73% | 3.3 m/s | 3.6 |
| 2003 | 18.4°C | 13.2°C | 8.1°C | 31.3°C | -2.6°C | 74 mm | 70% | 3.7 m/s | 3.5 |
| 2002 | 20.9°C | 14.9°C | 9.0°C | 30.7°C | -1.3°C | 36 mm | 63% | 3.7 m/s | 3.8 |
| 2001 | 20.3°C | 14.3°C | 8.3°C | 29.1°C | -0.1°C | 26 mm | 64% | 3 m/s | 4 |
| 2000 | 17.8°C | 12.3°C | 6.7°C | 25.4°C | 0.1°C | 62 mm | 69% | 3.7 m/s | 3.5 |
| 1999 | 17.3°C | 12.0°C | 6.7°C | 25.8°C | 1.2°C | 53 mm | 70% | 3.6 m/s | 3.4 |
| 1998 | 21.7°C | 15.7°C | 9.7°C | 33.8°C | 3.4°C | 21 mm | 64% | 3.4 m/s | 4 |
| 1997 | 21.4°C | 15.6°C | 9.9°C | 27.2°C | 2.5°C | 15 mm | 62% | 3.9 m/s | 4.1 |
| 1996 | 19.9°C | 14.2°C | 8.5°C | 29.4°C | 0.6°C | 42 mm | 65% | 3.2 m/s | 3.7 |
| 1995 | 20.0°C | 14.0°C | 7.9°C | 30.6°C | -1.1°C | 16 mm | 59% | 3.3 m/s | 4.1 |
| 1994 | 22.4°C | 16.3°C | 10.3°C | 30.3°C | 3.8°C | 43 mm | 63% | 3.3 m/s | 4.3 |
| 1993 | 16.6°C | 11.1°C | 5.6°C | 24.3°C | -0.3°C | 17 mm | 69% | 3.8 m/s | 3.6 |
| 1992 | 17.9°C | 12.1°C | 6.4°C | 24.4°C | -1.7°C | 50 mm | 65% | 3.8 m/s | 3.5 |
| 1991 | 18.1°C | 12.6°C | 7.1°C | 29.6°C | -0.1°C | 81 mm | 66% | 3.8 m/s | 3.8 |
| 1990 | 21.2°C | 15.0°C | 8.8°C | 31.9°C | 2.2°C | 31 mm | 60% | 3.7 m/s | 4 |
| 1989 | 20.4°C | 14.1°C | 7.7°C | 31.5°C | 0.5°C | 25 mm | 60% | 3.7 m/s | 4.4 |
| 1988 | 18.8°C | 13.3°C | 7.9°C | 29.3°C | 2.9°C | 72 mm | 63% | 4 m/s | 3.6 |
| 1987 | 20.5°C | 15.0°C | 9.5°C | 30.5°C | 4.4°C | 35 mm | 66% | 3.1 m/s | 3.8 |
| 1986 | 17.0°C | 12.1°C | 7.1°C | 22.1°C | 1.6°C | 69 mm | 69% | 3.1 m/s | 3.2 |
| 1985 ❄️ | 14.9°C | 10.0°C | 5.2°C | 23.8°C | -2.2°C | 57 mm | 73% | 3.9 m/s | 3.3 |
| 1984 | 15.8°C | 10.6°C | 5.4°C | 26.8°C | -2.5°C | 74 mm | 65% | 3.5 m/s | 3.4 |
| 1983 | 18.4°C | 13.2°C | 8.0°C | 33.0°C | 0.2°C | 60 mm | 64% | 3.9 m/s | — |
| 1982 | 18.7°C | 13.0°C | 7.4°C | 31.3°C | 0.4°C | 57 mm | 66% | 3.6 m/s | — |
| 1981 | 19.0°C | 13.3°C | 7.7°C | 29.8°C | 0.6°C | 96 mm | 67% | 3.5 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 19.9°C with lows near 8.5°C (mean 14.2°C), based on 45 years of NASA POWER data.
September averages 51 mm of rainfall in Portage La Prairie, about average for rainfall. The wettest on record was 145 mm in 2019.
The hottest September reached 35.3°C in 2023. The coldest dipped to -3.7°C in 2018.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 5.3°C. Daytime highs moved from 17.4°C to 23°C and overnight lows from 6.7°C to 11.6°C over the same span.
September is one of the warmer months of the year in Portage La Prairie and about average for rainfall, so plan for around 19.9°C daytime highs and 8.5°C at night.
Not quite — September is the 9th coolest month in Portage La Prairie, averaging 14.2°C.
For September in Portage La Prairie, pack light layers you can adjust through the day, with typical highs of 19.9°C and lows of 8.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 66% — moderately humid.
Average wind speed in September is 3.6 m/s. The windiest September on record averaged 4 m/s (1988).
The wettest September on record was 2019 with 145 mm. On average, September sees 51 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 Portage La Prairie 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.
