December is one of the cooler months of the year in Gravenhurst, with average highs near -1°C and lows around -8.1°C (mean -4.5°C). It is about average for rainfall, averaging 47 mm of rainfall and 88% relative humidity across the period.
December is one of the cooler months of the year in Gravenhurst. Across 45 years of records, the warmest December in Gravenhurst was 2015 — when the month averaged 2.1°C — while the coldest was 1989 at -13.1°C. Typical December days reach -1°C with nights near -8.1°C. The long-term trend is warming, about 0.7°C per decade.
December is about average for rainfall in Gravenhurst, averaging 47 mm of rainfall. The wettest December on record was 1983 with 136 mm, while the driest was 2017 at 16 mm.
Relative humidity in Gravenhurst during December averages 88%. The most humid December was 1983 at 99%, and the least humid was 2021 at 78%.
December receives about 1 kWh/m²/day of solar energy in Gravenhurst. The sunniest Decembers were 2001, 2003 and 2009, among others at 1.2 kWh/m²/day, and the cloudiest was 1984 at 0.7.
Average wind speed in Gravenhurst during December is 1.1 m/s. The windiest Decembers were 2008 and 2025 at 1.3 m/s, while the calmest was 1994 at 0.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -6.2°C | -4.2°C | -5.5°C | -3.7°C | -2.4°C | +3.8°C |
| Avg High | -2.4°C | -0.6°C | -1.9°C | -0.5°C | 0.8°C | +3.2°C |
| Avg Low | -10.0°C | -7.8°C | -9.1°C | -7.0°C | -5.7°C | +4.3°C |
| Avg Rain | 67 mm | 45 mm | 70 mm | 23 mm | 22 mm | -45 mm |
December temperatures in Gravenhurst have risen by about 3.3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -34.7°C (2004) to a record high of 16.2°C (1982).
Rainfall in December is about average for rainfall, averaging 47 mm, with a wettest year of 136 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.6°C per decade while lows rose 0.9°C per decade, narrowing the gap between day and night.
A quieter season to visit Gravenhurst
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Gravenhurst. That said, December — with days averaging -1°C and nights around -8.1°C (mean -4.5°C) and moderate rainfall (47 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 | -2.1°C | -6.1°C | -10.1°C | 6.2°C | -14.9°C | 21 mm | 80% | 1.3 m/s | — |
| 2024 | 0.5°C | -2.6°C | -5.8°C | 8.4°C | -18.0°C | 23 mm | 82% | 1 m/s | 1 |
| 2023 | 3.2°C | 0.3°C | -2.6°C | 8.9°C | -9.5°C | 20 mm | 82% | 0.9 m/s | 1 |
| 2022 | 1.2°C | -2.0°C | -5.2°C | 7.8°C | -12.2°C | 22 mm | 82% | 1.1 m/s | 1 |
| 2021 | 1.7°C | -1.8°C | -5.4°C | 14.9°C | -11.6°C | 24 mm | 78% | 1.2 m/s | 1.1 |
| 2020 | 0.5°C | -2.5°C | -5.4°C | 6.4°C | -12.4°C | 23 mm | 82% | 1.1 m/s | 1.1 |
| 2019 | -0.2°C | -3.5°C | -6.9°C | 5.5°C | -19.9°C | 25 mm | 87% | 1 m/s | 1 |
| 2018 | 0.0°C | -3.8°C | -7.5°C | 5.8°C | -13.5°C | 22 mm | 86% | 0.9 m/s | 1 |
| 2017 | -3.6°C | -6.8°C | -10.1°C | 9.9°C | -24.5°C | 16 mm | 81% | 1 m/s | 1 |
| 2016 | -0.1°C | -3.3°C | -6.5°C | 7.4°C | -18.0°C | 26 mm | 83% | 1.2 m/s | 0.9 |
| 2015 🔥 | 5.3°C | 2.1°C | -1.1°C | 13.4°C | -9.7°C | 25 mm | 85% | 1.1 m/s | 1 |
| 2014 | 0.0°C | -3.4°C | -6.8°C | 5.8°C | -13.9°C | 21 mm | 83% | 1 m/s | 0.9 |
| 2013 | -4.5°C | -7.3°C | -10.2°C | 6.1°C | -19.4°C | 20 mm | 85% | 1.1 m/s | 0.9 |
| 2012 | 0.4°C | -2.8°C | -6.0°C | 11.9°C | -14.4°C | 27 mm | 84% | 1 m/s | 0.9 |
| 2011 | 1.3°C | -2.1°C | -5.6°C | 9.4°C | -17.1°C | 19 mm | 82% | 1 m/s | 1 |
| 2010 | -3.6°C | -6.3°C | -9.1°C | 7.4°C | -15.1°C | 26 mm | 89% | 1.1 m/s | 1.1 |
| 2009 | -1.9°C | -5.2°C | -8.5°C | 8.5°C | -17.7°C | 35 mm | 88% | 1.1 m/s | 1.2 |
| 2008 | -2.5°C | -6.3°C | -10.0°C | 8.4°C | -20.6°C | 65 mm | 89% | 1.3 m/s | 1 |
| 2007 | -2.6°C | -6.2°C | -9.7°C | 3.8°C | -22.0°C | 46 mm | 95% | 1.1 m/s | 0.9 |
| 2006 | 1.6°C | -1.4°C | -4.3°C | 7.7°C | -17.4°C | 55 mm | 92% | 1.1 m/s | 1.1 |
| 2005 | -2.8°C | -5.9°C | -8.9°C | 1.3°C | -20.5°C | 59 mm | 93% | 1.1 m/s | 1 |
| 2004 | -2.7°C | -7.7°C | -12.6°C | 4.9°C | -34.7°C | 123 mm | 96% | 1.1 m/s | 1 |
| 2003 | -0.5°C | -3.9°C | -7.3°C | 4.0°C | -14.2°C | 67 mm | 90% | 1 m/s | 1.2 |
| 2002 | -2.1°C | -6.1°C | -10.1°C | 2.4°C | -25.4°C | 68 mm | 98% | 1.1 m/s | 1 |
| 2001 | 1.6°C | -1.4°C | -4.3°C | 13.2°C | -18.5°C | 93 mm | 94% | 1 m/s | 1.2 |
| 2000 | -6.8°C | -11.1°C | -15.4°C | 0.7°C | -24.1°C | 89 mm | 99% | 1.1 m/s | 1.2 |
| 1999 | -0.1°C | -4.2°C | -8.3°C | 10.7°C | -22.3°C | 90 mm | 92% | 1.1 m/s | 0.9 |
| 1998 | 1.8°C | -1.7°C | -5.2°C | 13.7°C | -23.7°C | 63 mm | 88% | 1.1 m/s | 1 |
| 1997 | -0.4°C | -4.0°C | -7.7°C | 5.1°C | -20.3°C | 23 mm | 87% | 1 m/s | 1.1 |
| 1996 | -0.3°C | -3.0°C | -5.7°C | 7.3°C | -18.7°C | 62 mm | 91% | 0.9 m/s | 0.9 |
| 1995 | -5.0°C | -8.8°C | -12.6°C | 1.3°C | -21.6°C | 19 mm | 92% | 1 m/s | 1.2 |
| 1994 | 1.5°C | -2.3°C | -6.0°C | 7.5°C | -16.0°C | 18 mm | 84% | 0.8 m/s | 0.9 |
| 1993 | -1.6°C | -5.2°C | -8.8°C | 4.7°C | -23.6°C | 31 mm | 91% | 1 m/s | 1 |
| 1992 | -0.5°C | -3.8°C | -7.1°C | 5.6°C | -15.7°C | 38 mm | 90% | 1.1 m/s | 1 |
| 1991 | -1.2°C | -5.1°C | -8.9°C | 9.1°C | -20.8°C | 52 mm | 88% | 1.1 m/s | 1.1 |
| 1990 | -0.4°C | -4.1°C | -7.9°C | 5.2°C | -20.0°C | 56 mm | 87% | 1.1 m/s | 1.1 |
| 1989 ❄️ | -8.6°C | -13.1°C | -17.7°C | 0.6°C | -28.7°C | 26 mm | 91% | 1 m/s | 1.2 |
| 1988 | -1.9°C | -6.0°C | -10.1°C | 6.3°C | -19.7°C | 55 mm | 85% | 1.1 m/s | 1 |
| 1987 | 0.5°C | -2.8°C | -6.0°C | 6.3°C | -19.1°C | 30 mm | 84% | 1 m/s | 1.1 |
| 1986 | -1.2°C | -5.1°C | -8.9°C | 1.8°C | -24.7°C | 38 mm | 93% | 1 m/s | 1.1 |
| 1985 | -3.7°C | -6.8°C | -9.9°C | 5.6°C | -20.4°C | 45 mm | 93% | 1 m/s | 1 |
| 1984 | -0.3°C | -4.0°C | -7.7°C | 9.1°C | -24.3°C | 121 mm | 92% | 1.1 m/s | 0.7 |
| 1983 🌧️ | -5.8°C | -10.3°C | -14.9°C | 0.5°C | -30.7°C | 136 mm | 99% | 1 m/s | — |
| 1982 | 1.5°C | -2.5°C | -6.5°C | 16.2°C | -21.3°C | 120 mm | 92% | 1.1 m/s | — |
| 1981 | -2.3°C | -5.1°C | -8.0°C | 3.3°C | -17.2°C | 34 mm | 92% | 1 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around -1°C with lows near -8.1°C (mean -4.5°C), based on 45 years of NASA POWER data.
December averages 47 mm of rainfall in Gravenhurst, about average for rainfall. The wettest on record was 136 mm in 1983.
The hottest December reached 16.2°C in 1982. The coldest dipped to -34.7°C in 2004.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 3.3°C. Daytime highs moved from -2.1°C to 0.9°C and overnight lows from -9.4°C to -5.8°C over the same span.
December is one of the cooler months of the year in Gravenhurst and about average for rainfall, so plan for around -1°C daytime highs and -8.1°C at night.
Not quite — December is the 3rd coolest month in Gravenhurst, averaging -4.5°C.
For December in Gravenhurst, pack warm layers and a jacket for chilly mornings, with typical highs of -1°C and lows of -8.1°C.
Relative humidity in December averages 88% — quite humid.
Average wind speed in December is 1.1 m/s. The windiest December on record averaged 1.3 m/s (2008).
The wettest December on record was 1983 with 136 mm. On average, December sees 47 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 Gravenhurst 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.
