October is one of the warmer months of the year in Saint Charles, with average highs near 16.7°C and lows around 5.6°C (mean 11.1°C). It is about average for rainfall, averaging 83 mm of rainfall and 75% relative humidity across the period.
October is one of the warmer months of the year in Saint Charles. Across 45 years of records, the warmest October in Saint Charles was 2021 — when the month averaged 14.7°C — while the coldest was 1987 at 7.2°C. Typical October days reach 16.7°C with nights near 5.6°C. The long-term trend is warming, about 0.5°C per decade.
October is about average for rainfall in Saint Charles, averaging 83 mm of rainfall. The wettest October on record was 2017 with 209 mm, while the driest was 2005 at 21 mm.
Relative humidity in Saint Charles during October averages 75%. The most humid October was 1986 at 85%, and the least humid was 2024 at 59%.
October receives about 3 kWh/m²/day of solar energy in Saint Charles. The sunniest October was 2024 at 3.9 kWh/m²/day, and the cloudiest was 2009 at 2.2.
Average wind speed in Saint Charles during October is 3.3 m/s. The windiest Octobers were 1990 and 2012 at 3.8 m/s, while the calmest were 1986, 2003 and 2011 at 2.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.3°C | 10.6°C | 11.2°C | 11.5°C | 12.6°C | +2.3°C |
| Avg High | 15.8°C | 16.4°C | 16.6°C | 16.9°C | 18.4°C | +2.6°C |
| Avg Low | 4.7°C | 4.8°C | 5.8°C | 6.1°C | 6.8°C | +2.1°C |
| Avg Rain | 73 mm | 83 mm | 82 mm | 96 mm | 76 mm | +3 mm |
October temperatures in Saint Charles have risen by about 2.1°C between 1981–1985 and 2021–2025.
October has ranged from a record low of -8°C (2019) to a record high of 31.7°C (2025).
Rainfall in October is about average for rainfall, averaging 83 mm, with a wettest year of 209 mm.
A good time to visit Saint Charles
October is a good time to visit Saint Charles, with days averaging 16.7°C and nights around 5.6°C (mean 11.1°C, warmer than Saint Charles's yearly average) and higher rainfall. August and July are marginally more temperate, but October still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 19.6°C | 13.9°C | 8.3°C | 31.7°C | -1.3°C | 55 mm | 70% | 3.1 m/s | 3.3 |
| 2024 | 21.1°C | 14.3°C | 7.4°C | 28.9°C | 0.5°C | 28 mm | 59% | 3.4 m/s | 3.9 |
| 2023 | 17.5°C | 12.3°C | 7.0°C | 29.8°C | -4.1°C | 86 mm | 75% | 3.4 m/s | 2.9 |
| 2022 | 17.4°C | 11.1°C | 4.8°C | 25.4°C | -3.1°C | 52 mm | 69% | 3.3 m/s | 3.5 |
| 2021 🔥 | 19.5°C | 14.7°C | 9.8°C | 30.6°C | 1.5°C | 158 mm | 80% | 3 m/s | 2.5 |
| 2020 | 15.1°C | 9.4°C | 3.6°C | 26.1°C | -3.4°C | 77 mm | 75% | 3.4 m/s | 2.9 |
| 2019 | 14.7°C | 9.7°C | 4.8°C | 27.9°C | -8.0°C | 149 mm | 82% | 3.4 m/s | 2.9 |
| 2018 | 15.3°C | 10.2°C | 5.1°C | 29.0°C | -4.4°C | 123 mm | 81% | 3.2 m/s | 2.9 |
| 2017 🌧️ | 18.1°C | 13.0°C | 8.0°C | 27.6°C | -3.2°C | 209 mm | 77% | 3.5 m/s | 2.6 |
| 2016 | 18.5°C | 13.3°C | 8.1°C | 26.7°C | 1.5°C | 87 mm | 81% | 3.1 m/s | 2.8 |
| 2015 | 17.4°C | 12.2°C | 7.0°C | 25.2°C | -2.1°C | 50 mm | 73% | 3.6 m/s | 3.2 |
| 2014 | 15.7°C | 10.7°C | 5.6°C | 24.0°C | 0.3°C | 80 mm | 79% | 3.1 m/s | 2.9 |
| 2013 | 16.8°C | 11.2°C | 5.5°C | 27.0°C | -3.7°C | 95 mm | 77% | 3 m/s | 2.9 |
| 2012 | 15.7°C | 10.2°C | 4.6°C | 25.4°C | -1.5°C | 84 mm | 74% | 3.8 m/s | 3 |
| 2011 | 17.4°C | 11.7°C | 5.9°C | 26.9°C | -1.0°C | 49 mm | 75% | 2.9 m/s | 3.4 |
| 2010 | 19.0°C | 12.7°C | 6.4°C | 29.9°C | -3.8°C | 38 mm | 69% | 3.2 m/s | 3.7 |
| 2009 | 13.1°C | 8.8°C | 4.5°C | 20.8°C | -3.7°C | 171 mm | 83% | 3.4 m/s | 2.2 |
| 2008 | 15.7°C | 10.6°C | 5.5°C | 27.0°C | -3.4°C | 62 mm | 78% | 3.2 m/s | 3.1 |
| 2007 | 19.8°C | 14.3°C | 8.7°C | 30.3°C | -0.3°C | 63 mm | 76% | 3.5 m/s | 3.1 |
| 2006 | 14.0°C | 8.8°C | 3.5°C | 26.1°C | -3.1°C | 116 mm | 77% | 3.4 m/s | 3 |
| 2005 | 18.2°C | 12.9°C | 7.6°C | 30.2°C | 0.5°C | 21 mm | 73% | 3 m/s | 3.2 |
| 2004 | 17.8°C | 12.2°C | 6.5°C | 25.9°C | -2.2°C | 67 mm | 73% | 3.4 m/s | 2.9 |
| 2003 | 17.4°C | 11.2°C | 4.9°C | 28.2°C | -2.1°C | 47 mm | 70% | 2.9 m/s | 3.4 |
| 2002 | 14.9°C | 9.7°C | 4.4°C | 27.6°C | -2.2°C | 55 mm | 75% | 3 m/s | 2.9 |
| 2001 | 15.6°C | 10.4°C | 5.3°C | 26.2°C | -2.1°C | 172 mm | 79% | 3.7 m/s | 2.7 |
| 2000 | 19.0°C | 12.8°C | 6.7°C | 26.7°C | -2.5°C | 45 mm | 74% | 3 m/s | 3.2 |
| 1999 | 17.2°C | 10.8°C | 4.5°C | 24.9°C | -4.0°C | 27 mm | 70% | 3.2 m/s | 3.3 |
| 1998 | 17.7°C | 12.3°C | 6.8°C | 24.6°C | -0.4°C | 117 mm | 78% | 3 m/s | 3.1 |
| 1997 | 17.5°C | 11.6°C | 5.6°C | 30.1°C | -4.5°C | 53 mm | 70% | 3.3 m/s | 3.2 |
| 1996 | 16.6°C | 10.6°C | 4.7°C | 24.8°C | -5.0°C | 65 mm | 75% | 3.5 m/s | 3 |
| 1995 | 16.7°C | 11.0°C | 5.4°C | 26.6°C | -0.6°C | 120 mm | 75% | 3.7 m/s | 3.1 |
| 1994 | 17.1°C | 11.3°C | 5.5°C | 25.5°C | -1.4°C | 70 mm | 73% | 3.2 m/s | 2.9 |
| 1993 | 14.2°C | 8.8°C | 3.3°C | 24.6°C | -3.0°C | 50 mm | 80% | 3.4 m/s | 3.1 |
| 1992 | 15.3°C | 9.5°C | 3.7°C | 24.8°C | -5.5°C | 27 mm | 78% | 3 m/s | 3 |
| 1991 | 15.7°C | 10.3°C | 4.9°C | 23.8°C | -3.3°C | 190 mm | 77% | 3.7 m/s | 2.9 |
| 1990 | 16.0°C | 9.9°C | 3.8°C | 26.9°C | -2.7°C | 107 mm | 75% | 3.8 m/s | 3.1 |
| 1989 | 16.8°C | 10.8°C | 4.8°C | 25.0°C | -1.9°C | 35 mm | 74% | 3.5 m/s | 3.2 |
| 1988 | 13.3°C | 7.6°C | 2.0°C | 22.8°C | -5.9°C | 78 mm | 66% | 3.5 m/s | 3.3 |
| 1987 ❄️ | 13.1°C | 7.2°C | 1.4°C | 20.8°C | -2.7°C | 36 mm | 73% | 3.1 m/s | 3.1 |
| 1986 | 15.5°C | 10.6°C | 5.6°C | 21.8°C | -0.4°C | 71 mm | 85% | 2.9 m/s | 2.6 |
| 1985 | 15.9°C | 10.8°C | 5.8°C | 23.3°C | 0.7°C | 141 mm | 78% | 3.2 m/s | 2.6 |
| 1984 | 18.4°C | 12.8°C | 7.1°C | 24.5°C | -0.7°C | 103 mm | 77% | 3 m/s | 2.3 |
| 1983 | 16.6°C | 11.3°C | 6.0°C | 27.5°C | -0.7°C | 84 mm | 75% | 3.4 m/s | — |
| 1982 | 18.1°C | 11.9°C | 5.7°C | 27.4°C | -3.3°C | 69 mm | 69% | 3.1 m/s | — |
| 1981 | 14.8°C | 9.3°C | 3.7°C | 22.4°C | -5.6°C | 43 mm | 77% | 3.1 m/s | — |
Actual recorded October data for each year, 1981–2025 — sourced from NASA POWER.
The average high in October is around 16.7°C with lows near 5.6°C (mean 11.1°C), based on 45 years of NASA POWER data.
October averages 83 mm of rainfall in Saint Charles, about average for rainfall. The wettest on record was 209 mm in 2017.
The hottest October reached 31.7°C in 2025. The coldest dipped to -8°C in 2019.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average October temperatures have risen by about 2.1°C. Daytime highs moved from 16.8°C to 19°C and overnight lows from 5.7°C to 7.5°C over the same span.
October is one of the warmer months of the year in Saint Charles and about average for rainfall, so plan for around 16.7°C daytime highs and 5.6°C at night.
Not quite — October is the 7th coolest month in Saint Charles, averaging 11.1°C.
For October in Saint Charles, pack warm layers and a jacket for chilly mornings, with typical highs of 16.7°C and lows of 5.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in October averages 75% — quite humid.
Average wind speed in October is 3.3 m/s. The windiest October on record averaged 3.8 m/s (1990).
The wettest October on record was 2017 with 209 mm. On average, October sees 83 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 Saint Charles behaves each October, 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 October specifically, along with year-by-year records and how the month has changed over the decades.
