September is one of the warmer months of the year in New Westminster, with average highs near 18.3°C and lows around 12.6°C (mean 15.5°C). It is one of the drier months, averaging 62 mm of rainfall and 78% relative humidity across the period.
September is one of the warmer months of the year in New Westminster. Across 45 years of records, the warmest September in New Westminster was 1995 — when the month averaged 17.2°C — while the coldest were 1985 and 1986 at 13.8°C. Typical September days reach 18.3°C with nights near 12.6°C. The long-term trend is warming, about 0.2°C per decade.
September is one of the drier months in New Westminster, averaging 62 mm of rainfall. The wettest September on record was 2021 with 163 mm, while the driest was 1991 at 5 mm.
Relative humidity in New Westminster during September averages 78%. The most humid September was 2025 at 88%, and the least humid was 1989 at 72%.
September receives about 3.7 kWh/m²/day of solar energy in New Westminster. The sunniest September was 1993 at 4.6 kWh/m²/day, and the cloudiest was 2019 at 3.
Average wind speed in New Westminster during September is 1.2 m/s. The windiest September was 2025 at 1.5 m/s, while the calmest were 1993 and 1998 at 0.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 14.8°C | 15.9°C | 15.2°C | 15.7°C | 15.8°C | +1°C |
| Avg High | 17.9°C | 19.0°C | 18.0°C | 18.4°C | 18.4°C | +0.5°C |
| Avg Low | 11.6°C | 12.9°C | 12.4°C | 13.0°C | 13.1°C | +1.5°C |
| Avg Rain | 54 mm | 40 mm | 57 mm | 83 mm | 83 mm | +29 mm |
September temperatures in New Westminster have risen by about 1°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 6.5°C (2024) to a record high of 28.3°C (2017).
Rainfall in September is one of the drier months, averaging 62 mm, with a wettest year of 163 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0°C per decade while lows rose 0.3°C per decade, narrowing the gap between day and night.
One of the best times to visit New Westminster
September is one of the best times to visit New Westminster. Expect days averaging 18.3°C and nights around 12.6°C (mean 15.5°C) — warmer than New Westminster's yearly average — with moderate rainfall (62 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 | 17.7°C | 15.3°C | 12.9°C | 23.1°C | 10.3°C | 108 mm | 88% | 1.5 m/s | 3.7 |
| 2024 | 17.3°C | 14.9°C | 12.5°C | 24.5°C | 6.5°C | 73 mm | 85% | 1.3 m/s | 3.5 |
| 2023 | 18.3°C | 15.6°C | 12.8°C | 22.9°C | 9.2°C | 58 mm | 80% | 1.2 m/s | 3.6 |
| 2022 | 19.9°C | 16.8°C | 13.7°C | 24.0°C | 11.3°C | 10 mm | 78% | 1.1 m/s | 4.2 |
| 2021 🌧️ | 17.4°C | 15.1°C | 12.7°C | 23.3°C | 10.5°C | 163 mm | 83% | 1.4 m/s | 3.1 |
| 2020 | 19.6°C | 16.8°C | 14.1°C | 25.9°C | 11.0°C | 84 mm | 81% | 1.1 m/s | 3.5 |
| 2019 | 17.8°C | 15.5°C | 13.2°C | 24.0°C | 7.9°C | 116 mm | 82% | 1.4 m/s | 3 |
| 2018 | 17.4°C | 14.9°C | 12.4°C | 24.2°C | 10.4°C | 110 mm | 82% | 1.3 m/s | 3.2 |
| 2017 | 19.5°C | 16.7°C | 14.0°C | 28.3°C | 9.7°C | 45 mm | 76% | 1.1 m/s | 3.6 |
| 2016 | 17.3°C | 14.8°C | 12.3°C | 21.2°C | 9.8°C | 62 mm | 81% | 1.3 m/s | 3.6 |
| 2015 | 17.1°C | 14.5°C | 11.9°C | 23.2°C | 9.1°C | 76 mm | 80% | 1.2 m/s | 3.4 |
| 2014 | 19.8°C | 16.8°C | 13.9°C | 25.9°C | 11.2°C | 71 mm | 77% | 1.2 m/s | 3.8 |
| 2013 | 18.8°C | 16.2°C | 13.7°C | 26.4°C | 9.4°C | 137 mm | 83% | 1.3 m/s | 3.3 |
| 2012 | 19.0°C | 15.9°C | 12.8°C | 25.3°C | 10.3°C | 11 mm | 76% | 0.9 m/s | 4.3 |
| 2011 | 19.4°C | 16.4°C | 13.4°C | 25.4°C | 10.3°C | 65 mm | 78% | 1.3 m/s | 3.6 |
| 2010 | 17.5°C | 14.9°C | 12.3°C | 22.8°C | 9.7°C | 134 mm | 84% | 1.3 m/s | 3.2 |
| 2009 | 18.8°C | 15.7°C | 12.7°C | 25.2°C | 8.2°C | 62 mm | 76% | 1.2 m/s | 3.7 |
| 2008 | 18.1°C | 15.1°C | 12.2°C | 23.6°C | 8.9°C | 25 mm | 77% | 1.1 m/s | 3.9 |
| 2007 | 17.0°C | 14.5°C | 11.9°C | 23.1°C | 8.1°C | 69 mm | 81% | 1.3 m/s | 3.5 |
| 2006 | 19.0°C | 16.0°C | 13.0°C | 25.4°C | 9.9°C | 41 mm | 76% | 1 m/s | 4.2 |
| 2005 | 17.0°C | 14.4°C | 11.8°C | 20.3°C | 9.8°C | 64 mm | 80% | 0.9 m/s | 3.6 |
| 2004 | 16.7°C | 14.3°C | 12.0°C | 20.1°C | 9.7°C | 92 mm | 83% | 1.2 m/s | 3.1 |
| 2003 | 19.3°C | 16.1°C | 12.9°C | 26.2°C | 10.5°C | 47 mm | 77% | 1.1 m/s | 4 |
| 2002 | 18.2°C | 15.1°C | 12.0°C | 22.4°C | 8.8°C | 47 mm | 77% | 1.1 m/s | 3.8 |
| 2001 | 17.9°C | 15.2°C | 12.6°C | 21.2°C | 9.4°C | 48 mm | 80% | 1.1 m/s | 3.8 |
| 2000 | 17.5°C | 15.1°C | 12.6°C | 22.6°C | 9.9°C | 71 mm | 78% | 1.2 m/s | 3.6 |
| 1999 | 18.2°C | 15.1°C | 11.9°C | 24.3°C | 8.5°C | 25 mm | 76% | 1.3 m/s | 4.2 |
| 1998 | 19.7°C | 16.5°C | 13.4°C | 25.2°C | 11.0°C | 13 mm | 77% | 0.8 m/s | 4.2 |
| 1997 | 19.1°C | 16.4°C | 13.8°C | 24.3°C | 10.0°C | 120 mm | 79% | 1.4 m/s | 3.6 |
| 1996 | 16.9°C | 14.2°C | 11.6°C | 22.1°C | 7.9°C | 68 mm | 79% | 1.2 m/s | 3.2 |
| 1995 🔥 | 20.3°C | 17.2°C | 14.2°C | 24.7°C | 10.9°C | 29 mm | 74% | 1 m/s | 4.2 |
| 1994 | 19.4°C | 16.5°C | 13.5°C | 23.6°C | 10.9°C | 53 mm | 78% | 1 m/s | 3.7 |
| 1993 | 19.5°C | 16.2°C | 12.9°C | 24.3°C | 7.2°C | 5 mm | 73% | 0.8 m/s | 4.6 |
| 1992 | 16.9°C | 14.0°C | 11.1°C | 21.7°C | 8.4°C | 57 mm | 77% | 1.4 m/s | 3.5 |
| 1991 | 19.0°C | 15.9°C | 12.8°C | 23.9°C | 10.8°C | 5 mm | 77% | 0.9 m/s | 4.3 |
| 1990 | 20.6°C | 17.1°C | 13.6°C | 25.5°C | 11.4°C | 20 mm | 73% | 0.9 m/s | 4.1 |
| 1989 | 19.8°C | 16.2°C | 12.5°C | 23.1°C | 9.5°C | 8 mm | 72% | 1 m/s | 4.4 |
| 1988 | 17.8°C | 14.7°C | 11.5°C | 25.6°C | 8.3°C | 79 mm | 76% | 1.1 m/s | 3.6 |
| 1987 | 19.1°C | 15.7°C | 12.2°C | 24.6°C | 9.2°C | 18 mm | 74% | 0.9 m/s | 3.9 |
| 1986 | 16.8°C | 13.8°C | 10.8°C | 22.1°C | 7.7°C | 60 mm | 78% | 1.1 m/s | 3.6 |
| 1985 ❄️ | 16.8°C | 13.8°C | 10.9°C | 21.0°C | 8.1°C | 45 mm | 75% | 1.2 m/s | 3.6 |
| 1984 | 17.1°C | 14.0°C | 11.0°C | 21.0°C | 7.8°C | 66 mm | 77% | 1.4 m/s | 3.4 |
| 1983 | 16.9°C | 14.0°C | 11.1°C | 22.5°C | 7.7°C | 83 mm | 76% | 1.4 m/s | — |
| 1982 | 18.6°C | 15.5°C | 12.5°C | 23.8°C | 9.5°C | 38 mm | 78% | 1.1 m/s | — |
| 1981 | 18.1°C | 15.1°C | 12.2°C | 25.1°C | 8.5°C | 89 mm | 78% | 1.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 18.3°C with lows near 12.6°C (mean 15.5°C), based on 45 years of NASA POWER data.
September averages 62 mm of rainfall in New Westminster, one of the drier months. The wettest on record was 163 mm in 2021.
The hottest September reached 28.3°C in 2017. The coldest dipped to 6.5°C in 2024.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1°C. Daytime highs moved from 17.5°C to 18.1°C and overnight lows from 11.5°C to 12.9°C over the same span.
September is one of the warmer months of the year in New Westminster and one of the drier months, so plan for around 18.3°C daytime highs and 12.6°C at night.
Not quite — September is the 10th coolest month in New Westminster, averaging 15.5°C.
For September in New Westminster, pack light layers you can adjust through the day, with typical highs of 18.3°C and lows of 12.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 78% — quite humid.
Average wind speed in September is 1.2 m/s. The windiest September on record averaged 1.5 m/s (2025).
The wettest September on record was 2021 with 163 mm. On average, September sees 62 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 New Westminster 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.
