October is one of the warmer months of the year in Mchenry, with average highs near 16°C and lows around 5.5°C (mean 10.8°C). It is about average for rainfall, averaging 77 mm of rainfall and 76% relative humidity across the period.
October is one of the warmer months of the year in Mchenry. Across 45 years of records, the warmest October in Mchenry was 2021 — when the month averaged 14.5°C — while the coldest was 1987 at 7°C. Typical October days reach 16°C with nights near 5.5°C. The long-term trend is warming, about 0.5°C per decade.
October is about average for rainfall in Mchenry, averaging 77 mm of rainfall. The wettest October on record was 1985 with 167 mm, while the driest was 2005 at 15 mm.
Relative humidity in Mchenry during October averages 76%. The most humid October was 1986 at 85%, and the least humid was 2024 at 60%.
October receives about 2.9 kWh/m²/day of solar energy in Mchenry. The sunniest October was 2024 at 3.7 kWh/m²/day, and the cloudiest were 1984 and 2009 at 2.2.
Average wind speed in Mchenry during October is 3.5 m/s. The windiest October was 1990 at 4.1 m/s, while the calmest were 2005, 2013 and 2021, among others at 3.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.8°C | 10.3°C | 10.8°C | 11.1°C | 12.2°C | +2.4°C |
| Avg High | 15.1°C | 15.8°C | 15.8°C | 16.2°C | 17.5°C | +2.4°C |
| Avg Low | 4.6°C | 4.8°C | 5.7°C | 6.0°C | 6.8°C | +2.2°C |
| Avg Rain | 80 mm | 73 mm | 73 mm | 90 mm | 66 mm | -14 mm |
October temperatures in Mchenry have risen by about 2.2°C between 1981–1985 and 2021–2025.
October has ranged from a record low of -7.6°C (2019) to a record high of 30.8°C (2025).
Rainfall in October is about average for rainfall, averaging 77 mm, with a wettest year of 167 mm.
A good time to visit Mchenry
October is a good time to visit Mchenry, with days averaging 16°C and nights around 5.5°C (mean 10.8°C, warmer than Mchenry's yearly average) and moderate 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 | 18.8°C | 13.7°C | 8.5°C | 30.8°C | -1.1°C | 46 mm | 72% | 3.2 m/s | 3.2 |
| 2024 | 20.2°C | 13.8°C | 7.5°C | 28.1°C | 0.5°C | 22 mm | 60% | 3.6 m/s | 3.7 |
| 2023 | 16.8°C | 11.9°C | 7.0°C | 28.9°C | -3.8°C | 92 mm | 76% | 3.5 m/s | 2.8 |
| 2022 | 16.4°C | 10.6°C | 4.8°C | 24.2°C | -2.9°C | 40 mm | 72% | 3.4 m/s | 3.3 |
| 2021 🔥 | 19.1°C | 14.5°C | 9.8°C | 29.7°C | 1.1°C | 126 mm | 80% | 3.1 m/s | 2.5 |
| 2020 | 13.8°C | 8.5°C | 3.1°C | 24.9°C | -3.5°C | 68 mm | 76% | 3.5 m/s | 2.8 |
| 2019 | 14.0°C | 9.3°C | 4.7°C | 27.1°C | -7.6°C | 149 mm | 83% | 3.6 m/s | 2.6 |
| 2018 | 14.2°C | 9.6°C | 4.9°C | 27.5°C | -4.2°C | 127 mm | 83% | 3.4 m/s | 2.7 |
| 2017 | 17.5°C | 12.7°C | 7.9°C | 27.5°C | -2.4°C | 154 mm | 77% | 3.7 m/s | 2.6 |
| 2016 | 17.9°C | 13.0°C | 8.0°C | 25.8°C | 1.5°C | 82 mm | 81% | 3.2 m/s | 2.6 |
| 2015 | 16.7°C | 11.8°C | 6.8°C | 24.8°C | -2.3°C | 47 mm | 74% | 3.8 m/s | 3 |
| 2014 | 15.3°C | 10.3°C | 5.3°C | 23.4°C | -0.2°C | 76 mm | 79% | 3.3 m/s | 2.8 |
| 2013 | 16.1°C | 10.7°C | 5.4°C | 26.4°C | -3.4°C | 81 mm | 79% | 3.1 m/s | 2.7 |
| 2012 | 15.4°C | 10.0°C | 4.6°C | 25.0°C | -1.9°C | 87 mm | 74% | 3.9 m/s | 2.9 |
| 2011 | 17.0°C | 11.6°C | 6.2°C | 26.3°C | -0.8°C | 53 mm | 75% | 3.2 m/s | 3.4 |
| 2010 | 18.2°C | 12.3°C | 6.3°C | 29.2°C | -3.3°C | 47 mm | 71% | 3.3 m/s | 3.5 |
| 2009 | 12.7°C | 8.5°C | 4.3°C | 20.7°C | -4.1°C | 150 mm | 83% | 3.5 m/s | 2.2 |
| 2008 | 15.2°C | 10.4°C | 5.7°C | 26.0°C | -3.0°C | 60 mm | 77% | 3.4 m/s | 3 |
| 2007 | 18.7°C | 13.7°C | 8.6°C | 29.1°C | -0.5°C | 63 mm | 79% | 3.6 m/s | 2.9 |
| 2006 | 13.5°C | 8.4°C | 3.3°C | 24.6°C | -2.9°C | 108 mm | 77% | 3.6 m/s | 2.8 |
| 2005 | 17.7°C | 12.6°C | 7.6°C | 29.8°C | 1.3°C | 15 mm | 74% | 3.1 m/s | 3.1 |
| 2004 | 17.2°C | 11.9°C | 6.6°C | 25.4°C | -1.4°C | 61 mm | 73% | 3.6 m/s | 2.7 |
| 2003 | 17.0°C | 10.9°C | 4.9°C | 27.7°C | -1.8°C | 42 mm | 70% | 3.1 m/s | 3.3 |
| 2002 | 13.6°C | 8.9°C | 4.2°C | 26.2°C | -2.7°C | 63 mm | 77% | 3.2 m/s | 2.7 |
| 2001 | 14.9°C | 10.1°C | 5.2°C | 24.7°C | -2.4°C | 136 mm | 79% | 3.9 m/s | 2.6 |
| 2000 | 18.0°C | 12.4°C | 6.8°C | 25.7°C | -1.9°C | 31 mm | 74% | 3.2 m/s | 3 |
| 1999 | 16.5°C | 10.5°C | 4.5°C | 23.4°C | -3.9°C | 24 mm | 71% | 3.5 m/s | 3.3 |
| 1998 | 16.9°C | 11.9°C | 6.9°C | 23.5°C | -0.7°C | 116 mm | 79% | 3.3 m/s | 3 |
| 1997 | 17.1°C | 11.4°C | 5.6°C | 30.0°C | -4.2°C | 43 mm | 71% | 3.5 m/s | 3.3 |
| 1996 | 16.3°C | 10.5°C | 4.7°C | 24.3°C | -4.9°C | 77 mm | 74% | 3.8 m/s | 2.9 |
| 1995 | 16.1°C | 10.7°C | 5.3°C | 25.9°C | -1.2°C | 120 mm | 76% | 3.8 m/s | 2.9 |
| 1994 | 16.6°C | 11.1°C | 5.7°C | 25.0°C | -1.1°C | 43 mm | 74% | 3.3 m/s | 2.8 |
| 1993 | 13.8°C | 8.5°C | 3.1°C | 24.1°C | -3.1°C | 28 mm | 80% | 3.6 m/s | 3 |
| 1992 | 14.6°C | 9.2°C | 3.8°C | 24.1°C | -5.3°C | 26 mm | 78% | 3.2 m/s | 2.9 |
| 1991 | 14.8°C | 9.7°C | 4.6°C | 23.1°C | -3.9°C | 165 mm | 77% | 3.9 m/s | 2.7 |
| 1990 | 15.6°C | 9.7°C | 3.8°C | 26.5°C | -2.6°C | 87 mm | 74% | 4.1 m/s | 3 |
| 1989 | 16.4°C | 10.6°C | 4.8°C | 24.0°C | -2.1°C | 34 mm | 74% | 3.7 m/s | 3.1 |
| 1988 | 12.6°C | 7.2°C | 1.9°C | 22.6°C | -5.8°C | 59 mm | 67% | 3.7 m/s | 3 |
| 1987 ❄️ | 12.6°C | 7.0°C | 1.5°C | 19.7°C | -2.6°C | 30 mm | 74% | 3.3 m/s | 2.9 |
| 1986 | 14.9°C | 10.2°C | 5.5°C | 21.1°C | 0.2°C | 49 mm | 85% | 3.1 m/s | 2.4 |
| 1985 🌧️ | 15.0°C | 10.2°C | 5.4°C | 21.9°C | 0.4°C | 167 mm | 79% | 3.3 m/s | 2.5 |
| 1984 | 17.6°C | 12.1°C | 6.7°C | 23.5°C | -1.6°C | 152 mm | 79% | 3.2 m/s | 2.2 |
| 1983 | 16.0°C | 11.0°C | 5.9°C | 27.2°C | -0.3°C | 78 mm | 75% | 3.6 m/s | — |
| 1982 | 17.2°C | 11.4°C | 5.6°C | 26.9°C | -2.8°C | 92 mm | 71% | 3.4 m/s | — |
| 1981 | 13.9°C | 8.8°C | 3.7°C | 20.6°C | -5.4°C | 57 mm | 78% | 3.3 m/s | — |
Actual recorded October data for each year, 1981–2025 — sourced from NASA POWER.
The average high in October is around 16°C with lows near 5.5°C (mean 10.8°C), based on 45 years of NASA POWER data.
October averages 77 mm of rainfall in Mchenry, about average for rainfall. The wettest on record was 167 mm in 1985.
The hottest October reached 30.8°C in 2025. The coldest dipped to -7.6°C in 2019.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average October temperatures have risen by about 2.2°C. Daytime highs moved from 15.9°C to 18.3°C and overnight lows from 5.5°C to 7.5°C over the same span.
October is one of the warmer months of the year in Mchenry and about average for rainfall, so plan for around 16°C daytime highs and 5.5°C at night.
Not quite — October is the 7th coolest month in Mchenry, averaging 10.8°C.
For October in Mchenry, pack warm layers and a jacket for chilly mornings, with typical highs of 16°C and lows of 5.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in October averages 76% — quite humid.
Average wind speed in October is 3.5 m/s. The windiest October on record averaged 4.1 m/s (1990).
The wettest October on record was 1985 with 167 mm. On average, October sees 77 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 Mchenry 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.
