December is one of the cooler months of the year in Simcoe, with average highs near 1.8°C and lows around -4.4°C (mean -1.3°C). It is about average for rainfall, averaging 49 mm of rainfall and 86% relative humidity across the period.
December is one of the cooler months of the year in Simcoe. Across 45 years of records, the warmest December in Simcoe was 2015 — when the month averaged 4.3°C — while the coldest was 1989 at -7.4°C. Typical December days reach 1.8°C with nights near -4.4°C. The long-term trend is warming, about 0.5°C per decade.
December is about average for rainfall in Simcoe, averaging 49 mm of rainfall. The wettest December on record was 1983 with 125 mm, while the driest was 1995 at 13 mm.
Relative humidity in Simcoe during December averages 86%. The most humid December was 1983 at 93%, and the least humid was 2025 at 79%.
December receives about 1.1 kWh/m²/day of solar energy in Simcoe. The sunniest Decembers were 1995 and 2000 at 1.3 kWh/m²/day, and the cloudiest were 1984, 2007 and 2016 at 0.9.
Average wind speed in Simcoe during December is 4.2 m/s. The windiest December was 2008 at 5.2 m/s, while the calmest was 2023 at 3.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -2.7°C | -0.9°C | -2.1°C | -0.7°C | 0.2°C | +2.9°C |
| Avg High | 0.4°C | 2.3°C | 1.1°C | 2.3°C | 3.4°C | +3°C |
| Avg Low | -5.7°C | -4.1°C | -5.2°C | -3.8°C | -3.0°C | +2.7°C |
| Avg Rain | 56 mm | 31 mm | 73 mm | 46 mm | 36 mm | -20 mm |
December temperatures in Simcoe have risen by about 2.6°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -21.8°C (1983) to a record high of 18°C (1982).
Rainfall in December is about average for rainfall, averaging 49 mm, with a wettest year of 125 mm.
A quieter season to visit Simcoe
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Simcoe. That said, December — with days averaging 1.8°C and nights around -4.4°C (mean -1.3°C) and moderate rainfall (49 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 | 0.9°C | -2.9°C | -6.6°C | 10.2°C | -11.8°C | 38 mm | 79% | 4.8 m/s | — |
| 2024 | 2.8°C | -0.2°C | -3.3°C | 11.0°C | -12.7°C | 39 mm | 82% | 4 m/s | 1 |
| 2023 | 5.6°C | 2.9°C | 0.1°C | 13.3°C | -4.2°C | 48 mm | 86% | 3.2 m/s | 1 |
| 2022 | 2.7°C | -0.3°C | -3.4°C | 11.0°C | -13.8°C | 34 mm | 82% | 4.6 m/s | 1 |
| 2021 | 5.2°C | 1.7°C | -1.9°C | 15.4°C | -5.6°C | 29 mm | 82% | 4.2 m/s | 1.2 |
| 2020 | 3.2°C | 0.3°C | -2.6°C | 10.6°C | -5.9°C | 30 mm | 81% | 4.4 m/s | 1.1 |
| 2019 | 2.8°C | -0.5°C | -3.8°C | 9.8°C | -13.6°C | 57 mm | 87% | 4 m/s | 1.1 |
| 2018 | 2.8°C | -0.1°C | -3.0°C | 12.2°C | -7.3°C | 41 mm | 89% | 3.3 m/s | 1 |
| 2017 | -0.9°C | -3.9°C | -6.8°C | 10.2°C | -19.1°C | 35 mm | 84% | 4.2 m/s | 1.1 |
| 2016 | 1.4°C | -1.4°C | -4.2°C | 10.3°C | -14.2°C | 54 mm | 84% | 5 m/s | 0.9 |
| 2015 🔥 | 7.9°C | 4.3°C | 0.7°C | 16.6°C | -4.5°C | 46 mm | 87% | 3.9 m/s | 1 |
| 2014 | 2.8°C | -0.1°C | -3.0°C | 10.1°C | -10.0°C | 30 mm | 84% | 3.7 m/s | 1 |
| 2013 | -0.5°C | -3.5°C | -6.5°C | 11.4°C | -16.4°C | 54 mm | 86% | 4.1 m/s | 1 |
| 2012 | 4.3°C | 1.2°C | -1.9°C | 13.3°C | -7.4°C | 59 mm | 89% | 3.7 m/s | 1.1 |
| 2011 | 3.8°C | 0.6°C | -2.5°C | 12.0°C | -10.9°C | 57 mm | 87% | 3.6 m/s | 1.1 |
| 2010 | -1.5°C | -4.1°C | -6.7°C | 6.3°C | -14.5°C | 25 mm | 88% | 4.3 m/s | 1 |
| 2009 | 0.7°C | -2.2°C | -5.0°C | 9.2°C | -13.8°C | 59 mm | 84% | 4.1 m/s | 1.1 |
| 2008 | 0.9°C | -2.7°C | -6.2°C | 11.7°C | -14.5°C | 93 mm | 84% | 5.2 m/s | 1 |
| 2007 | 0.6°C | -2.4°C | -5.4°C | 6.7°C | -12.0°C | 96 mm | 89% | 3.9 m/s | 0.9 |
| 2006 | 4.7°C | 1.6°C | -1.5°C | 11.6°C | -11.1°C | 73 mm | 87% | 4.6 m/s | 1.1 |
| 2005 | -0.9°C | -3.4°C | -5.9°C | 4.0°C | -13.4°C | 37 mm | 88% | 4.1 m/s | 1 |
| 2004 | 1.2°C | -2.5°C | -6.3°C | 13.0°C | -21.8°C | 100 mm | 88% | 4.5 m/s | 1 |
| 2003 | 2.2°C | -0.7°C | -3.5°C | 7.1°C | -10.3°C | 62 mm | 87% | 4 m/s | 1.2 |
| 2002 | 0.4°C | -2.7°C | -5.8°C | 5.5°C | -16.0°C | 53 mm | 88% | 4.4 m/s | 1 |
| 2001 | 4.0°C | 1.0°C | -1.9°C | 16.0°C | -8.3°C | 69 mm | 89% | 4.1 m/s | 1.2 |
| 2000 | -3.0°C | -6.6°C | -10.2°C | 2.8°C | -19.6°C | 90 mm | 91% | 4 m/s | 1.3 |
| 1999 | 2.4°C | -0.9°C | -4.3°C | 13.7°C | -13.5°C | 63 mm | 86% | 4.3 m/s | 1.1 |
| 1998 | 5.2°C | 1.2°C | -2.8°C | 16.2°C | -13.3°C | 57 mm | 82% | 4.3 m/s | 1.2 |
| 1997 | 2.3°C | -0.6°C | -3.6°C | 6.3°C | -10.3°C | 29 mm | 84% | 4 m/s | 1.2 |
| 1996 | 2.6°C | -0.3°C | -3.3°C | 10.5°C | -10.0°C | 26 mm | 86% | 4.1 m/s | 1 |
| 1995 | -1.2°C | -4.2°C | -7.2°C | 7.6°C | -12.8°C | 13 mm | 82% | 4.6 m/s | 1.3 |
| 1994 | 4.0°C | 0.7°C | -2.7°C | 12.9°C | -10.6°C | 16 mm | 84% | 3.4 m/s | 1 |
| 1993 | 0.7°C | -2.1°C | -4.8°C | 8.4°C | -14.1°C | 15 mm | 82% | 4.1 m/s | 1.1 |
| 1992 | 1.8°C | -1.0°C | -3.7°C | 7.2°C | -11.0°C | 26 mm | 85% | 4.2 m/s | 1 |
| 1991 | 2.2°C | -1.3°C | -4.8°C | 10.4°C | -13.3°C | 19 mm | 83% | 4.5 m/s | 1.2 |
| 1990 | 2.9°C | -0.7°C | -4.3°C | 10.1°C | -14.0°C | 44 mm | 84% | 4.6 m/s | 1 |
| 1989 ❄️ | -4.6°C | -7.4°C | -10.2°C | 3.5°C | -16.5°C | 19 mm | 82% | 3.9 m/s | 1.2 |
| 1988 | 0.7°C | -2.4°C | -5.4°C | 8.0°C | -14.6°C | 26 mm | 81% | 4.9 m/s | 1.1 |
| 1987 | 2.6°C | -0.3°C | -3.3°C | 9.5°C | -12.2°C | 34 mm | 85% | 4.5 m/s | 1.1 |
| 1986 | 1.1°C | -1.7°C | -4.6°C | 3.9°C | -14.8°C | 53 mm | 89% | 4 m/s | 1 |
| 1985 | -1.6°C | -4.4°C | -7.1°C | 8.9°C | -14.5°C | 32 mm | 88% | 5 m/s | 1 |
| 1984 | 3.6°C | 0.1°C | -3.4°C | 12.7°C | -10.6°C | 91 mm | 87% | 4.7 m/s | 0.9 |
| 1983 🌧️ | -3.4°C | -6.6°C | -9.8°C | 3.2°C | -21.8°C | 125 mm | 93% | 4.8 m/s | — |
| 1982 | 4.7°C | 1.1°C | -2.4°C | 18.0°C | -12.9°C | 103 mm | 87% | 4.1 m/s | — |
| 1981 | 0.6°C | -2.3°C | -5.2°C | 5.5°C | -11.2°C | 25 mm | 86% | 3.9 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 1.8°C with lows near -4.4°C (mean -1.3°C), based on 45 years of NASA POWER data.
December averages 49 mm of rainfall in Simcoe, about average for rainfall. The wettest on record was 125 mm in 1983.
The hottest December reached 18°C in 1982. The coldest dipped to -21.8°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 2.6°C. Daytime highs moved from 0.8°C to 3.4°C and overnight lows from -5.6°C to -3°C over the same span.
December is one of the cooler months of the year in Simcoe and about average for rainfall, so plan for around 1.8°C daytime highs and -4.4°C at night.
Not quite — December is the 3rd coolest month in Simcoe, averaging -1.3°C.
For December in Simcoe, pack warm layers and a jacket for chilly mornings, with typical highs of 1.8°C and lows of -4.4°C.
Relative humidity in December averages 86% — quite humid.
Average wind speed in December is 4.2 m/s. The windiest December on record averaged 5.2 m/s (2008).
The wettest December on record was 1983 with 125 mm. On average, December sees 49 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 Simcoe 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.
