December is one of the cooler months of the year in Windsor, with average highs near 1.4°C and lows around -5.1°C (mean -1.8°C). It is one of the drier months, averaging 55 mm of rainfall and 86% relative humidity across the period.
December is one of the cooler months of the year in Windsor. Across 45 years of records, the warmest December in Windsor was 2015 — when the month averaged 4°C — while the coldest was 1989 at -7.7°C. Typical December days reach 1.4°C with nights near -5.1°C. The long-term trend is warming, about 0.6°C per decade.
December is one of the drier months in Windsor, averaging 55 mm of rainfall. The wettest December on record was 2008 with 94 mm, while the driest was 1993 at 22 mm.
Relative humidity in Windsor during December averages 86%. The most humid December was 2000 at 92%, and the least humid was 1998 at 81%.
December receives about 1.2 kWh/m²/day of solar energy in Windsor. The sunniest December was 2000 at 1.5 kWh/m²/day, and the cloudiest were 2012, 2015 and 2016, among others at 1.1.
Average wind speed in Windsor during December is 4 m/s. The windiest December was 2008 at 4.9 m/s, while the calmest was 1994 at 3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -3.3°C | -1.4°C | -2.4°C | -1.2°C | -0.2°C | +3.1°C |
| Avg High | -0.1°C | 1.9°C | 0.8°C | 1.9°C | 3.1°C | +3.2°C |
| Avg Low | -6.6°C | -4.7°C | -5.5°C | -4.4°C | -3.5°C | +3.1°C |
| Avg Rain | 57 mm | 49 mm | 66 mm | 49 mm | 55 mm | -2 mm |
December temperatures in Windsor have risen by about 3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -21.2°C (1983) to a record high of 19.6°C (1982).
Rainfall in December is one of the drier months, averaging 55 mm, with a wettest year of 94 mm.
A quieter season to visit Windsor
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Windsor. That said, December — with days averaging 1.4°C and nights around -5.1°C (mean -1.8°C) and moderate rainfall (55 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 0.2°C | -3.4°C | -7.1°C | 11.8°C | -16.2°C | 66 mm | 83% | 4.4 m/s | — |
| 2024 | 2.5°C | -0.4°C | -3.4°C | 11.5°C | -11.6°C | 69 mm | 84% | 4 m/s | 1.2 |
| 2023 | 6.0°C | 2.9°C | -0.3°C | 15.7°C | -5.7°C | 52 mm | 87% | 3.1 m/s | 1.2 |
| 2022 | 2.6°C | -0.8°C | -4.2°C | 11.5°C | -15.7°C | 43 mm | 82% | 4.3 m/s | 1.2 |
| 2021 | 4.6°C | 0.9°C | -2.7°C | 15.5°C | -7.8°C | 60 mm | 85% | 3.9 m/s | 1.3 |
| 2020 | 2.8°C | -0.3°C | -3.4°C | 12.1°C | -6.6°C | 41 mm | 84% | 4 m/s | 1.2 |
| 2019 | 3.4°C | 0.1°C | -3.2°C | 11.8°C | -11.7°C | 50 mm | 87% | 3.9 m/s | 1.3 |
| 2018 | 2.7°C | -0.4°C | -3.4°C | 11.6°C | -8.7°C | 52 mm | 88% | 3.2 m/s | 1.3 |
| 2017 | -0.9°C | -4.0°C | -7.2°C | 11.4°C | -18.5°C | 37 mm | 84% | 3.9 m/s | 1.3 |
| 2016 | -0.1°C | -3.3°C | -6.4°C | 9.1°C | -17.9°C | 50 mm | 88% | 4.4 m/s | 1.1 |
| 2015 🔥 | 7.4°C | 4.0°C | 0.5°C | 16.2°C | -4.1°C | 58 mm | 87% | 4 m/s | 1.1 |
| 2014 | 2.4°C | -0.4°C | -3.2°C | 9.6°C | -11.5°C | 36 mm | 84% | 3.6 m/s | 1.2 |
| 2013 | -1.4°C | -4.6°C | -7.9°C | 11.3°C | -17.1°C | 57 mm | 86% | 3.7 m/s | 1.2 |
| 2012 | 4.3°C | 0.8°C | -2.6°C | 14.8°C | -9.3°C | 62 mm | 87% | 3.6 m/s | 1.1 |
| 2011 | 3.1°C | -0.1°C | -3.2°C | 12.0°C | -8.1°C | 60 mm | 87% | 3.5 m/s | 1.3 |
| 2010 | -1.6°C | -4.4°C | -7.2°C | 7.6°C | -13.8°C | 27 mm | 87% | 4.2 m/s | 1.2 |
| 2009 | 0.4°C | -2.7°C | -5.8°C | 7.8°C | -11.2°C | 64 mm | 85% | 4 m/s | 1.3 |
| 2008 🌧️ | -0.2°C | -3.9°C | -7.7°C | 11.5°C | -18.5°C | 94 mm | 87% | 4.9 m/s | 1.2 |
| 2007 | 0.4°C | -2.5°C | -5.3°C | 6.3°C | -10.6°C | 80 mm | 89% | 3.9 m/s | 1.1 |
| 2006 | 4.4°C | 1.2°C | -2.1°C | 11.8°C | -10.7°C | 83 mm | 87% | 4.3 m/s | 1.3 |
| 2005 | -1.4°C | -4.1°C | -6.8°C | 2.6°C | -13.5°C | 50 mm | 89% | 3.8 m/s | 1.2 |
| 2004 | 1.2°C | -2.2°C | -5.6°C | 14.6°C | -16.7°C | 61 mm | 86% | 4.6 m/s | 1.3 |
| 2003 | 2.0°C | -0.8°C | -3.6°C | 5.7°C | -8.5°C | 66 mm | 85% | 3.9 m/s | 1.4 |
| 2002 | 0.8°C | -2.3°C | -5.5°C | 7.1°C | -13.7°C | 39 mm | 84% | 4.2 m/s | 1.3 |
| 2001 | 4.4°C | 1.2°C | -2.0°C | 17.0°C | -9.2°C | 41 mm | 87% | 4 m/s | 1.4 |
| 2000 | -3.9°C | -7.5°C | -11.0°C | 1.4°C | -19.3°C | 79 mm | 92% | 4 m/s | 1.5 |
| 1999 | 2.4°C | -1.2°C | -4.8°C | 15.0°C | -12.2°C | 60 mm | 82% | 4.1 m/s | 1.2 |
| 1998 | 5.3°C | 1.1°C | -3.1°C | 17.5°C | -12.1°C | 36 mm | 81% | 4 m/s | 1.4 |
| 1997 | 1.9°C | -1.1°C | -4.0°C | 5.3°C | -12.6°C | 38 mm | 88% | 3.6 m/s | 1.3 |
| 1996 | 1.2°C | -1.6°C | -4.4°C | 6.9°C | -16.0°C | 66 mm | 89% | 3.9 m/s | 1.1 |
| 1995 | -1.3°C | -4.5°C | -7.7°C | 5.8°C | -13.6°C | 24 mm | 84% | 4.2 m/s | 1.4 |
| 1994 | 3.5°C | -0.2°C | -4.0°C | 12.4°C | -11.1°C | 56 mm | 89% | 3 m/s | 1.1 |
| 1993 | 0.4°C | -2.3°C | -5.1°C | 8.2°C | -14.8°C | 22 mm | 85% | 4 m/s | 1.1 |
| 1992 | 1.5°C | -1.4°C | -4.3°C | 6.6°C | -10.8°C | 55 mm | 86% | 4 m/s | 1.1 |
| 1991 | 2.0°C | -1.6°C | -5.2°C | 11.8°C | -11.2°C | 46 mm | 86% | 4.2 m/s | 1.3 |
| 1990 | 2.0°C | -1.5°C | -4.9°C | 9.0°C | -14.4°C | 89 mm | 86% | 4.4 m/s | 1.2 |
| 1989 ❄️ | -4.3°C | -7.7°C | -11.0°C | 2.8°C | -18.0°C | 27 mm | 83% | 3.7 m/s | 1.3 |
| 1988 | 0.5°C | -3.0°C | -6.5°C | 9.5°C | -14.4°C | 40 mm | 82% | 4.5 m/s | 1.2 |
| 1987 | 1.7°C | -1.3°C | -4.3°C | 9.2°C | -13.7°C | 92 mm | 88% | 4.3 m/s | 1.2 |
| 1986 | 0.8°C | -2.1°C | -5.0°C | 3.6°C | -13.3°C | 46 mm | 90% | 3.5 m/s | 1.2 |
| 1985 | -2.7°C | -6.3°C | -9.9°C | 8.4°C | -18.2°C | 31 mm | 88% | 4.4 m/s | 1.2 |
| 1984 | 3.3°C | -0.3°C | -4.0°C | 13.9°C | -12.7°C | 82 mm | 85% | 4.4 m/s | 1.1 |
| 1983 | -4.1°C | -7.2°C | -10.4°C | 3.5°C | -21.2°C | 78 mm | 90% | 4.5 m/s | — |
| 1982 | 4.5°C | 1.2°C | -2.0°C | 19.6°C | -11.2°C | 73 mm | 85% | 4.3 m/s | — |
| 1981 | -0.2°C | -3.3°C | -6.4°C | 7.5°C | -13.5°C | 48 mm | 88% | 3.8 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 1.4°C with lows near -5.1°C (mean -1.8°C), based on 45 years of NASA POWER data.
December averages 55 mm of rainfall in Windsor, one of the drier months. The wettest on record was 94 mm in 2008.
The hottest December reached 19.6°C in 1982. The coldest dipped to -21.2°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 3°C. Daytime highs moved from 0.2°C to 3.2°C and overnight lows from -6.5°C to -3.5°C over the same span.
December is one of the cooler months of the year in Windsor and one of the drier months, so plan for around 1.4°C daytime highs and -5.1°C at night.
Not quite — December is the 3rd coolest month in Windsor, averaging -1.8°C.
For December in Windsor, pack warm layers and a jacket for chilly mornings, with typical highs of 1.4°C and lows of -5.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 86% — quite humid.
Average wind speed in December is 4 m/s. The windiest December on record averaged 4.9 m/s (2008).
The wettest December on record was 2008 with 94 mm. On average, December sees 55 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 Windsor behaves each December, 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 December specifically, along with year-by-year records and how the month has changed over the decades.
