September is one of the warmer months of the year in Charlottetown, with average highs near 18.7°C and lows around 13°C (mean 15.9°C). It is about average for rainfall, averaging 86 mm of rainfall and 79% relative humidity across the period.
September is one of the warmer months of the year in Charlottetown. Across 45 years of records, the warmest September in Charlottetown was 1999 — when the month averaged 18.8°C — while the coldest was 1986 at 13.1°C. Typical September days reach 18.7°C with nights near 13°C. The long-term trend is warming, about 0.4°C per decade.
September is about average for rainfall in Charlottetown, averaging 86 mm of rainfall. The wettest September on record was 2012 with 216 mm, while the driest was 1985 at 19 mm.
Relative humidity in Charlottetown during September averages 79%. The most humid September was 2013 at 84%, and the least humid was 1995 at 70%.
September receives about 3.7 kWh/m²/day of solar energy in Charlottetown. The sunniest Septembers were 2003 and 2025 at 4.3 kWh/m²/day, and the cloudiest were 1991 and 1997 at 3.1.
Average wind speed in Charlottetown during September is 3.3 m/s. The windiest September was 2004 at 3.9 m/s, while the calmest were 2003 and 2023 at 2.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 15.1°C | 15.7°C | 15.6°C | 16.3°C | 17.1°C | +2°C |
| Avg High | 17.9°C | 18.7°C | 18.5°C | 19.1°C | 19.9°C | +2°C |
| Avg Low | 12.2°C | 12.7°C | 12.8°C | 13.4°C | 14.2°C | +2°C |
| Avg Rain | 80 mm | 80 mm | 84 mm | 104 mm | 81 mm | +1 mm |
September temperatures in Charlottetown have risen by about 1.7°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 6°C (1981) to a record high of 28.6°C (2010).
Rainfall in September is about average for rainfall, averaging 86 mm, with a wettest year of 216 mm.
One of the best times to visit Charlottetown
September is one of the best times to visit Charlottetown. Expect days averaging 18.7°C and nights around 13°C (mean 15.9°C) — warmer than Charlottetown's yearly average — with higher rainfall (86 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 | 17.5°C | 14.3°C | 26.7°C | 10.6°C | 37 mm | 72% | 2.9 m/s | 4.3 |
| 2024 | 19.4°C | 16.7°C | 14.0°C | 24.7°C | 11.4°C | 48 mm | 81% | 3.1 m/s | 3.8 |
| 2023 | 20.4°C | 17.7°C | 14.9°C | 26.9°C | 9.7°C | 57 mm | 83% | 2.7 m/s | 3.6 |
| 2022 | 19.6°C | 16.9°C | 14.2°C | 25.1°C | 9.9°C | 138 mm | 77% | 3.5 m/s | 3.8 |
| 2021 | 20.0°C | 17.2°C | 14.3°C | 23.7°C | 10.7°C | 139 mm | 83% | 3.5 m/s | 3.7 |
| 2020 | 19.6°C | 16.6°C | 13.6°C | 24.4°C | 9.1°C | 68 mm | 76% | 3.5 m/s | 3.9 |
| 2019 | 17.6°C | 15.1°C | 12.5°C | 23.1°C | 8.5°C | 127 mm | 80% | 3.6 m/s | 3.6 |
| 2018 | 19.4°C | 16.4°C | 13.4°C | 25.3°C | 8.2°C | 118 mm | 76% | 3.1 m/s | 4 |
| 2017 | 20.0°C | 17.0°C | 14.0°C | 24.4°C | 8.3°C | 83 mm | 82% | 3.1 m/s | 3.5 |
| 2016 | 19.1°C | 16.4°C | 13.6°C | 25.8°C | 8.2°C | 81 mm | 81% | 3.3 m/s | 3.7 |
| 2015 | 20.1°C | 17.1°C | 14.1°C | 24.7°C | 9.8°C | 57 mm | 81% | 3.3 m/s | 3.9 |
| 2014 | 19.0°C | 16.0°C | 13.0°C | 25.5°C | 8.6°C | 85 mm | 76% | 3.3 m/s | 4 |
| 2013 | 18.4°C | 15.6°C | 12.8°C | 23.5°C | 9.5°C | 120 mm | 84% | 3.4 m/s | 3.2 |
| 2012 🌧️ | 19.3°C | 16.5°C | 13.8°C | 24.5°C | 9.7°C | 216 mm | 83% | 3.3 m/s | 3.6 |
| 2011 | 19.2°C | 16.3°C | 13.5°C | 23.8°C | 9.8°C | 42 mm | 81% | 2.8 m/s | 4.1 |
| 2010 | 18.8°C | 16.2°C | 13.7°C | 28.6°C | 9.0°C | 107 mm | 83% | 3.3 m/s | 3.2 |
| 2009 | 17.2°C | 14.3°C | 11.4°C | 22.0°C | 8.4°C | 59 mm | 80% | 3.4 m/s | 4.2 |
| 2008 | 17.5°C | 15.1°C | 12.7°C | 22.8°C | 8.5°C | 132 mm | 83% | 3.4 m/s | 3.4 |
| 2007 | 18.0°C | 15.2°C | 12.5°C | 24.5°C | 8.8°C | 71 mm | 78% | 3.5 m/s | 4 |
| 2006 | 18.5°C | 15.8°C | 13.0°C | 22.3°C | 9.7°C | 41 mm | 81% | 3 m/s | 3.8 |
| 2005 | 19.3°C | 16.6°C | 13.8°C | 24.2°C | 9.7°C | 128 mm | 79% | 3.6 m/s | 3.7 |
| 2004 | 17.6°C | 14.9°C | 12.1°C | 23.2°C | 9.2°C | 77 mm | 76% | 3.9 m/s | 3.7 |
| 2003 | 20.0°C | 16.8°C | 13.6°C | 24.5°C | 10.3°C | 53 mm | 80% | 2.7 m/s | 4.3 |
| 2002 | 19.2°C | 16.1°C | 12.9°C | 25.8°C | 7.9°C | 141 mm | 79% | 3.4 m/s | 3.6 |
| 2001 | 19.6°C | 16.5°C | 13.5°C | 26.0°C | 9.6°C | 65 mm | 75% | 3 m/s | 4.1 |
| 2000 | 18.0°C | 15.1°C | 12.1°C | 24.2°C | 6.4°C | 77 mm | 77% | 3.4 m/s | 3.8 |
| 1999 🔥 | 22.1°C | 18.8°C | 15.4°C | 27.1°C | 10.7°C | 102 mm | 80% | 2.9 m/s | 3.9 |
| 1998 | 18.0°C | 15.3°C | 12.6°C | 21.7°C | 9.3°C | 104 mm | 81% | 3 m/s | 3.4 |
| 1997 | 18.5°C | 15.6°C | 12.8°C | 23.2°C | 7.5°C | 79 mm | 79% | 3.2 m/s | 3.1 |
| 1996 | 17.4°C | 15.2°C | 12.9°C | 25.0°C | 8.7°C | 170 mm | 81% | 3.7 m/s | 3.3 |
| 1995 | 18.2°C | 14.9°C | 11.5°C | 23.0°C | 7.1°C | 32 mm | 70% | 3.1 m/s | 4 |
| 1994 | 17.9°C | 15.1°C | 12.2°C | 21.1°C | 9.4°C | 56 mm | 77% | 3 m/s | 3.8 |
| 1993 | 19.3°C | 16.0°C | 12.7°C | 24.2°C | 8.7°C | 39 mm | 75% | 3.4 m/s | 3.6 |
| 1992 | 19.2°C | 16.1°C | 13.0°C | 23.5°C | 7.5°C | 33 mm | 76% | 3 m/s | 3.7 |
| 1991 | 17.4°C | 14.7°C | 12.0°C | 23.3°C | 6.9°C | 106 mm | 81% | 3.4 m/s | 3.1 |
| 1990 | 18.6°C | 15.4°C | 12.2°C | 24.7°C | 9.7°C | 78 mm | 77% | 3.2 m/s | 3.5 |
| 1989 | 19.2°C | 15.7°C | 12.2°C | 25.7°C | 6.3°C | 59 mm | 75% | 3.4 m/s | 3.9 |
| 1988 | 17.2°C | 14.3°C | 11.5°C | 21.9°C | 8.9°C | 58 mm | 76% | 3.7 m/s | 3.6 |
| 1987 | 17.5°C | 14.9°C | 12.4°C | 23.0°C | 6.8°C | 136 mm | 80% | 3.6 m/s | 3.6 |
| 1986 ❄️ | 16.0°C | 13.1°C | 10.3°C | 22.5°C | 7.2°C | 98 mm | 76% | 3.3 m/s | 3.6 |
| 1985 | 18.8°C | 15.9°C | 13.0°C | 23.3°C | 9.9°C | 19 mm | 76% | 2.9 m/s | 4 |
| 1984 | 17.4°C | 14.5°C | 11.7°C | 22.1°C | 7.2°C | 104 mm | 79% | 3.6 m/s | 4 |
| 1983 | 19.3°C | 16.4°C | 13.5°C | 26.2°C | 10.0°C | 65 mm | 79% | 3.3 m/s | — |
| 1982 | 18.0°C | 15.2°C | 12.5°C | 22.3°C | 9.9°C | 102 mm | 83% | 2.9 m/s | — |
| 1981 | 18.0°C | 15.5°C | 12.9°C | 22.9°C | 6.0°C | 83 mm | 79% | 3.8 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 13°C (mean 15.9°C), based on 45 years of NASA POWER data.
September averages 86 mm of rainfall in Charlottetown, about average for rainfall. The wettest on record was 216 mm in 2012.
The hottest September reached 28.6°C in 2010. The coldest dipped to 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 1.7°C. Daytime highs moved from 18.3°C to 20°C and overnight lows from 12.7°C to 14.3°C over the same span.
September is one of the warmer months of the year in Charlottetown and about average for rainfall, so plan for around 18.7°C daytime highs and 13°C at night.
Not quite — September is the 10th coolest month in Charlottetown, averaging 15.9°C.
For September in Charlottetown, pack light layers you can adjust through the day, with typical highs of 18.7°C and lows of 13°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 79% — quite humid.
Average wind speed in September is 3.3 m/s. The windiest September on record averaged 3.9 m/s (2004).
The wettest September on record was 2012 with 216 mm. On average, September sees 86 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 Charlottetown 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.
