December is one of the cooler months of the year in Saint-Hyacinthe, with average highs near -2.6°C and lows around -11.1°C (mean -6.8°C). It is about average for rainfall, averaging 84 mm of rainfall and 91% relative humidity across the period.
December is one of the cooler months of the year in Saint-Hyacinthe. Across 45 years of records, the warmest December in Saint-Hyacinthe was 2015 — when the month averaged 0.4°C — while the coldest was 1989 at -19.2°C. Typical December days reach -2.6°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 Saint-Hyacinthe, averaging 84 mm of rainfall. The wettest December on record was 2003 with 172 mm, while the driest was 1985 at 38 mm.
Relative humidity in Saint-Hyacinthe during December averages 91%. The most humid December was 1995 at 96%, and the least humid was 2020 at 84%.
December receives about 1 kWh/m²/day of solar energy in Saint-Hyacinthe. 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 Saint-Hyacinthe during December is 2.9 m/s. The windiest December was 2025 at 3.5 m/s, while the calmest were 2018 and 2023 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -8.8°C | -6.5°C | -7.4°C | -6.2°C | -4.4°C | +4.4°C |
| Avg High | -4.3°C | -2.1°C | -3.0°C | -2.2°C | -0.6°C | +3.7°C |
| Avg Low | -13.4°C | -10.9°C | -11.8°C | -10.4°C | -8.1°C | +5.3°C |
| Avg Rain | 69 mm | 76 mm | 109 mm | 84 mm | 76 mm | +7 mm |
December temperatures in Saint-Hyacinthe have risen by about 2.9°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -40.9°C (1993) to a record high of 18.3°C (2015).
Rainfall in December is about average for rainfall, averaging 84 mm, with a wettest year of 172 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 Saint-Hyacinthe
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Saint-Hyacinthe. That said, December — with days averaging -2.6°C and nights around -11.1°C (mean -6.8°C) and higher rainfall (84 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 | -4.0°C | -8.5°C | -13.0°C | 7.5°C | -24.3°C | 56 mm | 87% | 3.5 m/s | — |
| 2024 | -1.7°C | -5.0°C | -8.3°C | 8.5°C | -17.8°C | 81 mm | 89% | 2.8 m/s | 1 |
| 2023 | 0.8°C | -2.7°C | -6.1°C | 12.3°C | -22.0°C | 113 mm | 91% | 2.3 m/s | 1 |
| 2022 | 0.2°C | -3.5°C | -7.1°C | 6.9°C | -15.3°C | 86 mm | 88% | 3.3 m/s | 1 |
| 2021 | 0.1°C | -3.8°C | -7.8°C | 12.1°C | -15.3°C | 65 mm | 84% | 3.1 m/s | 1 |
| 2020 | 1.1°C | -2.7°C | -6.6°C | 16.6°C | -17.9°C | 57 mm | 84% | 3.3 m/s | 0.9 |
| 2019 | -1.6°C | -5.5°C | -9.4°C | 7.1°C | -18.1°C | 61 mm | 90% | 3.1 m/s | 1.1 |
| 2018 | -3.0°C | -8.2°C | -13.3°C | 6.1°C | -26.0°C | 93 mm | 93% | 2.3 m/s | 1.1 |
| 2017 | -5.9°C | -9.7°C | -13.5°C | 6.8°C | -33.7°C | 53 mm | 89% | 2.8 m/s | 1.1 |
| 2016 | -1.7°C | -6.3°C | -11.0°C | 6.4°C | -28.8°C | 81 mm | 90% | 3 m/s | 0.9 |
| 2015 🔥 | 3.9°C | 0.4°C | -3.2°C | 18.3°C | -13.1°C | 112 mm | 91% | 2.6 m/s | 0.9 |
| 2014 | -1.8°C | -5.3°C | -8.8°C | 5.1°C | -19.5°C | 75 mm | 89% | 2.7 m/s | 1 |
| 2013 | -5.5°C | -9.9°C | -14.3°C | 4.4°C | -27.6°C | 73 mm | 91% | 2.5 m/s | 1 |
| 2012 | -1.7°C | -5.7°C | -9.8°C | 10.3°C | -20.6°C | 110 mm | 91% | 2.9 m/s | 1 |
| 2011 | -0.2°C | -4.2°C | -8.2°C | 6.6°C | -27.0°C | 87 mm | 89% | 2.7 m/s | 1.1 |
| 2010 | -4.2°C | -8.1°C | -12.1°C | 7.9°C | -20.8°C | 93 mm | 94% | 2.8 m/s | 0.9 |
| 2009 | -3.9°C | -7.7°C | -11.6°C | 6.3°C | -26.5°C | 104 mm | 93% | 2.6 m/s | 1.1 |
| 2008 | -3.7°C | -9.0°C | -14.2°C | 6.0°C | -27.0°C | 134 mm | 91% | 3.3 m/s | 1 |
| 2007 | -4.5°C | -9.3°C | -14.0°C | 2.2°C | -26.1°C | 114 mm | 94% | 2.8 m/s | 1 |
| 2006 | 0.6°C | -2.7°C | -6.0°C | 7.6°C | -16.0°C | 108 mm | 92% | 3 m/s | 1 |
| 2005 | -3.3°C | -7.4°C | -11.6°C | 1.8°C | -27.3°C | 92 mm | 93% | 2.9 m/s | 1.1 |
| 2004 | -4.1°C | -9.6°C | -15.1°C | 6.7°C | -35.4°C | 120 mm | 93% | 3.1 m/s | 1 |
| 2003 🌧️ | -3.3°C | -7.4°C | -11.5°C | 3.3°C | -23.0°C | 172 mm | 94% | 3.2 m/s | 1.2 |
| 2002 | -3.0°C | -7.6°C | -12.2°C | 2.1°C | -27.3°C | 52 mm | 93% | 2.8 m/s | 1.1 |
| 2001 | 1.8°C | -1.9°C | -5.6°C | 14.5°C | -15.4°C | 58 mm | 91% | 2.5 m/s | 1.2 |
| 2000 | -6.8°C | -11.6°C | -16.5°C | 5.2°C | -29.5°C | 136 mm | 92% | 3.1 m/s | 1.3 |
| 1999 | -1.2°C | -5.4°C | -9.6°C | 9.9°C | -29.5°C | 66 mm | 89% | 2.8 m/s | 0.9 |
| 1998 | 2.1°C | -2.5°C | -7.0°C | 14.0°C | -28.8°C | 66 mm | 85% | 3.2 m/s | 1 |
| 1997 | -4.0°C | -9.2°C | -14.4°C | 1.1°C | -29.2°C | 61 mm | 95% | 2.4 m/s | 1.1 |
| 1996 | 0.2°C | -3.1°C | -6.4°C | 7.3°C | -25.0°C | 108 mm | 91% | 2.7 m/s | 0.9 |
| 1995 | -6.7°C | -11.4°C | -16.2°C | 0.5°C | -28.1°C | 75 mm | 96% | 2.6 m/s | 1.2 |
| 1994 | -1.0°C | -5.4°C | -9.7°C | 6.7°C | -22.8°C | 66 mm | 91% | 2.6 m/s | 1 |
| 1993 | -3.6°C | -8.4°C | -13.1°C | 3.9°C | -40.9°C | 65 mm | 93% | 2.8 m/s | 1 |
| 1992 | -1.3°C | -5.0°C | -8.6°C | 6.9°C | -19.7°C | 40 mm | 88% | 3.2 m/s | 1 |
| 1991 | -3.4°C | -7.9°C | -12.3°C | 8.2°C | -23.4°C | 69 mm | 90% | 3 m/s | 1.1 |
| 1990 | -1.8°C | -6.6°C | -11.5°C | 5.3°C | -26.0°C | 148 mm | 93% | 2.9 m/s | 1.1 |
| 1989 ❄️ | -13.8°C | -19.2°C | -24.7°C | 0.9°C | -34.6°C | 47 mm | 95% | 2.6 m/s | 1.3 |
| 1988 | -3.6°C | -8.0°C | -12.4°C | 5.1°C | -23.6°C | 40 mm | 86% | 3.2 m/s | 1 |
| 1987 | -2.1°C | -5.9°C | -9.7°C | 5.1°C | -22.9°C | 55 mm | 94% | 2.4 m/s | 1.1 |
| 1986 | -3.1°C | -8.2°C | -13.2°C | 1.7°C | -23.6°C | 51 mm | 94% | 2.7 m/s | 1 |
| 1985 | -4.6°C | -9.2°C | -13.8°C | 4.5°C | -31.8°C | 38 mm | 90% | 2.9 m/s | 1.1 |
| 1984 | -1.7°C | -5.8°C | -9.9°C | 6.5°C | -24.1°C | 114 mm | 90% | 3 m/s | 0.9 |
| 1983 | -6.6°C | -12.2°C | -17.8°C | 1.1°C | -36.1°C | 154 mm | 95% | 3.1 m/s | — |
| 1982 | 0.1°C | -4.2°C | -8.5°C | 13.5°C | -23.7°C | 78 mm | 88% | 3.1 m/s | — |
| 1981 | -3.3°C | -6.8°C | -10.3°C | 4.6°C | -23.2°C | 47 mm | 95% | 2.6 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around -2.6°C with lows near -11.1°C (mean -6.8°C), based on 45 years of NASA POWER data.
December averages 84 mm of rainfall in Saint-Hyacinthe, about average for rainfall. The wettest on record was 172 mm in 2003.
The hottest December reached 18.3°C in 2015. The coldest dipped to -40.9°C in 1993.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 2.9°C. Daytime highs moved from -3.2°C to -0.9°C and overnight lows from -12.1°C to -8.5°C over the same span.
December is one of the cooler months of the year in Saint-Hyacinthe and about average for rainfall, so plan for around -2.6°C daytime highs and -11.1°C at night.
Not quite — December is the 3rd coolest month in Saint-Hyacinthe, averaging -6.8°C.
For December in Saint-Hyacinthe, pack warm layers and a jacket for chilly mornings, with typical highs of -2.6°C and lows of -11.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 91% — quite humid.
Average wind speed in December is 2.9 m/s. The windiest December on record averaged 3.5 m/s (2025).
The wettest December on record was 2003 with 172 mm. On average, December sees 84 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 Saint-Hyacinthe 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.
