December is one of the cooler months of the year in Granby, with average highs near -2.9°C and lows around -11.1°C (mean -7°C). It is about average for rainfall, averaging 85 mm of rainfall and 93% relative humidity across the period.
December is one of the cooler months of the year in Granby. Across 45 years of records, the warmest December in Granby was 2015 — when the month averaged -0.4°C — while the coldest was 1989 at -18.8°C. Typical December days reach -2.9°C with nights near -11.1°C. The long-term trend is warming, about 0.8°C per decade.
December is about average for rainfall in Granby, averaging 85 mm of rainfall. The wettest December on record was 2003 with 181 mm, while the driest was 1985 at 43 mm.
Relative humidity in Granby during December averages 93%. The most humid Decembers were 1983 and 1995 at 99%, and the least humid was 2021 at 84%.
December receives about 1 kWh/m²/day of solar energy in Granby. The sunniest Decembers were 1989 and 2000 at 1.3 kWh/m²/day, and the cloudiest were 2015, 2016 and 2020, among others at 0.9.
Average wind speed in Granby during December is 0.9 m/s. The windiest Decembers were 2020 and 2025 at 1.1 m/s, while the calmest were 2015, 2018 and 2023, among others at 0.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -9.0°C | -6.7°C | -7.5°C | -6.4°C | -4.6°C | +4.4°C |
| Avg High | -4.8°C | -2.5°C | -3.4°C | -2.5°C | -0.9°C | +3.9°C |
| Avg Low | -13.2°C | -11.0°C | -11.7°C | -10.3°C | -8.3°C | +4.9°C |
| Avg Rain | 75 mm | 85 mm | 112 mm | 78 mm | 69 mm | -6 mm |
December temperatures in Granby have risen by about 3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -36.2°C (1983) to a record high of 16.8°C (2015).
Rainfall in December is about average for rainfall, averaging 85 mm, with a wettest year of 181 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 Granby
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Granby. That said, December — with days averaging -2.9°C and nights around -11.1°C (mean -7°C) and higher rainfall (85 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 | -4.5°C | -8.8°C | -13.1°C | 9.5°C | -20.9°C | 56 mm | 91% | 1.1 m/s | — |
| 2024 | -2.0°C | -5.2°C | -8.5°C | 8.4°C | -19.0°C | 75 mm | 90% | 0.9 m/s | 1 |
| 2023 | 1.0°C | -2.6°C | -6.1°C | 15.1°C | -16.7°C | 92 mm | 93% | 0.8 m/s | 1 |
| 2022 | -0.2°C | -3.6°C | -6.9°C | 7.6°C | -13.3°C | 81 mm | 88% | 1 m/s | 1 |
| 2021 | -0.2°C | -4.2°C | -8.3°C | 10.8°C | -17.0°C | 59 mm | 84% | 1 m/s | 1 |
| 2020 | 0.6°C | -3.2°C | -7.0°C | 15.8°C | -18.2°C | 51 mm | 85% | 1.1 m/s | 0.9 |
| 2019 | -2.0°C | -5.9°C | -9.7°C | 6.6°C | -18.5°C | 65 mm | 91% | 1 m/s | 1.1 |
| 2018 | -3.0°C | -8.0°C | -12.9°C | 8.6°C | -24.5°C | 74 mm | 94% | 0.8 m/s | 1.1 |
| 2017 | -6.3°C | -9.8°C | -13.3°C | 5.8°C | -32.0°C | 48 mm | 90% | 0.9 m/s | 1.1 |
| 2016 | -2.3°C | -6.6°C | -10.9°C | 4.6°C | -29.1°C | 74 mm | 92% | 1 m/s | 0.9 |
| 2015 🔥 | 3.0°C | -0.4°C | -3.7°C | 16.8°C | -13.1°C | 103 mm | 92% | 0.8 m/s | 0.9 |
| 2014 | -2.1°C | -5.6°C | -9.2°C | 5.1°C | -19.8°C | 74 mm | 92% | 0.8 m/s | 1 |
| 2013 | -5.2°C | -9.6°C | -14.0°C | 4.6°C | -26.6°C | 72 mm | 93% | 0.8 m/s | 1 |
| 2012 | -1.8°C | -5.7°C | -9.6°C | 9.4°C | -20.6°C | 105 mm | 92% | 0.9 m/s | 1 |
| 2011 | -0.6°C | -4.4°C | -8.3°C | 5.4°C | -21.7°C | 77 mm | 90% | 0.9 m/s | 1.1 |
| 2010 | -4.6°C | -8.0°C | -11.4°C | 7.3°C | -20.5°C | 86 mm | 95% | 0.9 m/s | 0.9 |
| 2009 | -4.3°C | -7.9°C | -11.6°C | 7.1°C | -26.2°C | 96 mm | 95% | 0.9 m/s | 1.1 |
| 2008 | -3.9°C | -8.6°C | -13.2°C | 6.6°C | -24.8°C | 135 mm | 93% | 1 m/s | 1 |
| 2007 | -5.0°C | -9.3°C | -13.6°C | 0.7°C | -26.6°C | 114 mm | 98% | 0.9 m/s | 1 |
| 2006 | 0.1°C | -3.1°C | -6.3°C | 6.3°C | -16.8°C | 111 mm | 93% | 0.9 m/s | 1 |
| 2005 | -3.8°C | -7.8°C | -11.8°C | 3.0°C | -26.9°C | 97 mm | 96% | 0.9 m/s | 1.1 |
| 2004 | -3.9°C | -9.1°C | -14.2°C | 7.5°C | -34.0°C | 122 mm | 95% | 1 m/s | 1 |
| 2003 🌧️ | -3.8°C | -7.5°C | -11.3°C | 1.8°C | -23.5°C | 181 mm | 95% | 1 m/s | 1.2 |
| 2002 | -3.8°C | -8.2°C | -12.7°C | 1.1°C | -30.5°C | 61 mm | 97% | 0.9 m/s | 1.1 |
| 2001 | 1.1°C | -2.4°C | -5.9°C | 13.8°C | -16.7°C | 60 mm | 93% | 0.8 m/s | 1.2 |
| 2000 | -6.6°C | -11.5°C | -16.3°C | 10.6°C | -29.5°C | 139 mm | 95% | 1 m/s | 1.3 |
| 1999 | -1.7°C | -5.8°C | -9.8°C | 9.5°C | -25.1°C | 71 mm | 92% | 0.9 m/s | 0.9 |
| 1998 | 1.1°C | -3.3°C | -7.8°C | 13.3°C | -29.4°C | 71 mm | 88% | 1 m/s | 1 |
| 1997 | -4.0°C | -9.1°C | -14.1°C | 0.5°C | -27.9°C | 65 mm | 98% | 0.8 m/s | 1.1 |
| 1996 | -0.2°C | -3.5°C | -6.9°C | 8.6°C | -26.9°C | 135 mm | 94% | 0.9 m/s | 0.9 |
| 1995 | -7.3°C | -11.7°C | -16.1°C | 0.2°C | -27.0°C | 90 mm | 99% | 0.8 m/s | 1.2 |
| 1994 | -1.3°C | -5.5°C | -9.6°C | 5.9°C | -20.8°C | 70 mm | 93% | 0.9 m/s | 1 |
| 1993 | -3.7°C | -8.2°C | -12.7°C | 3.7°C | -35.7°C | 69 mm | 94% | 1 m/s | 1 |
| 1992 | -1.7°C | -5.4°C | -9.2°C | 4.5°C | -20.6°C | 50 mm | 91% | 1 m/s | 1 |
| 1991 | -3.8°C | -8.2°C | -12.6°C | 6.8°C | -25.6°C | 74 mm | 92% | 0.9 m/s | 1.1 |
| 1990 | -2.0°C | -6.5°C | -11.1°C | 5.0°C | -25.3°C | 151 mm | 94% | 0.9 m/s | 1.1 |
| 1989 ❄️ | -14.0°C | -18.8°C | -23.6°C | 0.3°C | -32.2°C | 56 mm | 98% | 0.9 m/s | 1.3 |
| 1988 | -4.3°C | -8.6°C | -12.9°C | 4.7°C | -23.7°C | 45 mm | 88% | 1 m/s | 1 |
| 1987 | -2.9°C | -6.5°C | -10.0°C | 4.3°C | -23.5°C | 58 mm | 96% | 0.8 m/s | 1.1 |
| 1986 | -2.9°C | -7.6°C | -12.2°C | 3.3°C | -21.9°C | 47 mm | 95% | 0.9 m/s | 1 |
| 1985 | -5.1°C | -9.5°C | -13.8°C | 4.8°C | -32.0°C | 43 mm | 93% | 1 m/s | 1.1 |
| 1984 | -2.2°C | -6.1°C | -10.1°C | 5.8°C | -24.5°C | 121 mm | 93% | 0.9 m/s | 0.9 |
| 1983 | -7.0°C | -12.0°C | -17.0°C | 0.3°C | -36.2°C | 159 mm | 99% | 1 m/s | — |
| 1982 | -0.2°C | -4.5°C | -8.7°C | 13.3°C | -21.8°C | 83 mm | 88% | 1 m/s | — |
| 1981 | -4.3°C | -7.5°C | -10.7°C | 3.0°C | -23.2°C | 64 mm | 98% | 0.8 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around -2.9°C with lows near -11.1°C (mean -7°C), based on 45 years of NASA POWER data.
December averages 85 mm of rainfall in Granby, about average for rainfall. The wettest on record was 181 mm in 2003.
The hottest December reached 16.8°C in 2015. The coldest dipped to -36.2°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 -3.8°C to -1.2°C and overnight lows from -12.1°C to -8.6°C over the same span.
December is one of the cooler months of the year in Granby and about average for rainfall, so plan for around -2.9°C daytime highs and -11.1°C at night.
Not quite — December is the 3rd coolest month in Granby, averaging -7°C.
For December in Granby, pack warm layers and a jacket for chilly mornings, with typical highs of -2.9°C and lows of -11.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 93% — quite humid.
Average wind speed in December is 0.9 m/s. The windiest December on record averaged 1.1 m/s (2020).
The wettest December on record was 2003 with 181 mm. On average, December sees 85 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 Granby 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.
