December is one of the cooler months of the year in Lethbridge, with average highs near -2.6°C and lows around -10.4°C (mean -6.5°C). It is one of the drier months, averaging 27 mm of rainfall and 83% relative humidity across the period.
December is one of the cooler months of the year in Lethbridge. Across 45 years of records, the warmest December in Lethbridge was 2023 — when the month averaged 0°C — while the coldest was 1983 at -17.2°C. Typical December days reach -2.6°C with nights near -10.4°C. The long-term trend is warming, about 0.7°C per decade.
December is one of the drier months in Lethbridge, averaging 27 mm of rainfall. The wettest December on record was 1996 with 52 mm, while the driest was 1986 at 10 mm.
Relative humidity in Lethbridge during December averages 83%. The most humid December was 1996 at 94%, and the least humid was 1997 at 74%.
December receives about 1 kWh/m²/day of solar energy in Lethbridge. The sunniest Decembers were 1991, 2010 and 2014, among others at 1.2 kWh/m²/day, and the cloudiest were 1989 and 2008 at 0.8.
Average wind speed in Lethbridge during December is 3.4 m/s. The windiest December was 2011 at 4.4 m/s, while the calmest was 1983 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -8.0°C | -6.6°C | -6.2°C | -6.5°C | -4.6°C | +3.4°C |
| Avg High | -4.0°C | -2.7°C | -2.3°C | -2.7°C | -0.8°C | +3.2°C |
| Avg Low | -12.0°C | -10.5°C | -10.2°C | -10.3°C | -8.5°C | +3.5°C |
| Avg Rain | 25 mm | 29 mm | 26 mm | 28 mm | 27 mm | +2 mm |
December temperatures in Lethbridge have risen by about 5.4°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -41.3°C (1990) to a record high of 12.5°C (2021).
Rainfall in December is one of the drier months, averaging 27 mm, with a wettest year of 52 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.6°C per decade while lows rose 0.8°C per decade, narrowing the gap between day and night.
A quieter season to visit Lethbridge
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Lethbridge. That said, December — with days averaging -2.6°C and nights around -10.4°C (mean -6.5°C) and low rainfall (27 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 | 1.4°C | -2.9°C | -7.1°C | 8.0°C | -20.8°C | 41 mm | 84% | 3.5 m/s | — |
| 2024 | 0.9°C | -2.5°C | -6.0°C | 4.8°C | -15.7°C | 17 mm | 86% | 3.1 m/s | 0.9 |
| 2023 🔥 | 3.4°C | 0.0°C | -3.5°C | 11.2°C | -8.7°C | 19 mm | 78% | 3.4 m/s | 1 |
| 2022 | -6.5°C | -10.5°C | -14.5°C | 2.1°C | -32.4°C | 37 mm | 89% | 2.7 m/s | 1.1 |
| 2021 | -4.1°C | -8.4°C | -12.7°C | 12.5°C | -28.5°C | 32 mm | 78% | 3.3 m/s | 0.9 |
| 2020 | -0.1°C | -3.5°C | -6.9°C | 4.8°C | -14.7°C | 16 mm | 85% | 3.6 m/s | 1 |
| 2019 | -0.3°C | -3.9°C | -7.4°C | 6.2°C | -14.5°C | 22 mm | 87% | 3.4 m/s | 1.1 |
| 2018 | 0.0°C | -3.7°C | -7.3°C | 4.9°C | -16.9°C | 17 mm | 77% | 3.7 m/s | 1 |
| 2017 | -4.1°C | -7.8°C | -11.5°C | 5.6°C | -31.5°C | 41 mm | 77% | 3.4 m/s | 0.9 |
| 2016 | -7.7°C | -11.0°C | -14.3°C | 3.0°C | -26.3°C | 29 mm | 82% | 3.5 m/s | 0.9 |
| 2015 | -1.2°C | -4.9°C | -8.7°C | 6.3°C | -19.0°C | 26 mm | 83% | 3 m/s | 1 |
| 2014 | -1.6°C | -5.4°C | -9.3°C | 4.2°C | -26.5°C | 32 mm | 89% | 3.1 m/s | 1.2 |
| 2013 | -5.4°C | -9.7°C | -14.1°C | 3.2°C | -35.6°C | 41 mm | 87% | 3.7 m/s | 1 |
| 2012 | -3.5°C | -7.1°C | -10.7°C | 5.3°C | -21.2°C | 29 mm | 85% | 3 m/s | 1 |
| 2011 | -0.5°C | -4.2°C | -7.9°C | 4.8°C | -14.8°C | 23 mm | 80% | 4.4 m/s | 1.1 |
| 2010 | -3.0°C | -7.2°C | -11.4°C | 3.1°C | -25.6°C | 24 mm | 88% | 2.5 m/s | 1.2 |
| 2009 | -7.0°C | -11.1°C | -15.2°C | 2.2°C | -27.5°C | 31 mm | 83% | 2.8 m/s | 1 |
| 2008 | -6.9°C | -10.8°C | -14.8°C | 6.9°C | -28.9°C | 46 mm | 82% | 3.4 m/s | 0.8 |
| 2007 | -2.3°C | -6.2°C | -10.1°C | 3.3°C | -17.7°C | 21 mm | 80% | 3.4 m/s | 0.9 |
| 2006 | 0.1°C | -3.5°C | -7.0°C | 5.1°C | -15.5°C | 23 mm | 80% | 4 m/s | 1 |
| 2005 | -2.7°C | -6.4°C | -10.2°C | 5.9°C | -23.2°C | 30 mm | 87% | 3.4 m/s | 1.1 |
| 2004 | 0.1°C | -3.6°C | -7.2°C | 6.1°C | -20.4°C | 34 mm | 79% | 3.7 m/s | 0.9 |
| 2003 | 0.3°C | -3.5°C | -7.3°C | 5.3°C | -17.3°C | 14 mm | 80% | 3.4 m/s | 1.1 |
| 2002 | 1.9°C | -2.2°C | -6.3°C | 9.0°C | -12.4°C | 22 mm | 80% | 3.1 m/s | 1.1 |
| 2001 | -2.1°C | -6.5°C | -11.0°C | 3.1°C | -17.9°C | 18 mm | 85% | 3.2 m/s | 1.1 |
| 2000 | -4.0°C | -8.4°C | -12.7°C | 5.1°C | -26.2°C | 26 mm | 83% | 2.9 m/s | 1 |
| 1999 | 1.3°C | -2.1°C | -5.5°C | 6.5°C | -11.4°C | 32 mm | 78% | 4.2 m/s | 1 |
| 1998 | -2.5°C | -6.4°C | -10.3°C | 7.7°C | -23.8°C | 35 mm | 76% | 3.9 m/s | 0.9 |
| 1997 | 1.0°C | -2.6°C | -6.2°C | 5.8°C | -13.1°C | 13 mm | 74% | 4.1 m/s | 1.1 |
| 1996 🌧️ | -8.7°C | -12.6°C | -16.5°C | 1.5°C | -32.8°C | 52 mm | 94% | 2.8 m/s | 0.9 |
| 1995 | -2.0°C | -6.4°C | -10.7°C | 6.6°C | -24.7°C | 29 mm | 83% | 3 m/s | 1.1 |
| 1994 | -1.5°C | -5.3°C | -9.1°C | 4.8°C | -20.9°C | 21 mm | 82% | 3.4 m/s | 1 |
| 1993 | -0.3°C | -3.7°C | -7.2°C | 4.3°C | -15.2°C | 22 mm | 83% | 3.6 m/s | 0.9 |
| 1992 | -6.9°C | -11.6°C | -16.3°C | 1.6°C | -35.4°C | 35 mm | 87% | 3.2 m/s | 1 |
| 1991 | 0.6°C | -2.9°C | -6.5°C | 4.4°C | -12.1°C | 15 mm | 80% | 4.1 m/s | 1.2 |
| 1990 | -7.9°C | -12.3°C | -16.8°C | 3.1°C | -41.3°C | 34 mm | 86% | 4.3 m/s | 1 |
| 1989 | -2.4°C | -6.0°C | -9.6°C | 6.6°C | -32.5°C | 36 mm | 85% | 3.6 m/s | 0.8 |
| 1988 | -1.9°C | -5.9°C | -9.9°C | 5.2°C | -22.5°C | 21 mm | 79% | 3.6 m/s | 0.9 |
| 1987 | -0.4°C | -4.2°C | -7.9°C | 8.4°C | -19.6°C | 20 mm | 76% | 3.6 m/s | 1 |
| 1986 | -0.2°C | -4.1°C | -8.0°C | 3.3°C | -15.8°C | 10 mm | 79% | 3.9 m/s | 1.2 |
| 1985 | -3.4°C | -7.1°C | -10.9°C | 1.5°C | -29.3°C | 12 mm | 88% | 3.7 m/s | 1 |
| 1984 | -9.3°C | -13.6°C | -18.0°C | 2.4°C | -30.1°C | 39 mm | 86% | 3.3 m/s | 1 |
| 1983 ❄️ | -12.3°C | -17.2°C | -22.0°C | 0.2°C | -41.1°C | 31 mm | 91% | 2.3 m/s | — |
| 1982 | -3.3°C | -7.1°C | -10.9°C | 3.6°C | -20.4°C | 41 mm | 88% | 3.3 m/s | — |
| 1981 | -2.5°C | -6.4°C | -10.4°C | 4.9°C | -21.7°C | 16 mm | 80% | 3.1 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 -10.4°C (mean -6.5°C), based on 45 years of NASA POWER data.
December averages 27 mm of rainfall in Lethbridge, one of the drier months. The wettest on record was 52 mm in 1996.
The hottest December reached 12.5°C in 2021. The coldest dipped to -41.3°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 5.4°C. Daytime highs moved from -6.2°C to -1°C and overnight lows from -14.4°C to -8.8°C over the same span.
December is one of the cooler months of the year in Lethbridge and one of the drier months, so plan for around -2.6°C daytime highs and -10.4°C at night.
Yes — December is the coldest month of the year in Lethbridge, averaging -6.5°C.
For December in Lethbridge, pack warm layers and a jacket for chilly mornings, with typical highs of -2.6°C and lows of -10.4°C.
Relative humidity in December averages 83% — quite humid.
Average wind speed in December is 3.4 m/s. The windiest December on record averaged 4.4 m/s (2011).
The wettest December on record was 1996 with 52 mm. On average, December sees 27 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 Lethbridge 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.
