December is one of the cooler months of the year in Bellevue, with average highs near 3.5°C and lows around -1.5°C (mean 1°C). It is a relatively wet time of year, averaging 243 mm of rainfall and 92% relative humidity across the period.
December is one of the cooler months of the year in Bellevue. Across 45 years of records, the warmest December in Bellevue was 2023 — when the month averaged 4.5°C — while the coldest was 1983 at -3.4°C. Typical December days reach 3.5°C with nights near -1.5°C. The long-term trend is warming, about 0.4°C per decade.
December is a relatively wet time of year in Bellevue, averaging 243 mm of rainfall. The wettest December on record was 2025 with 517 mm, while the driest was 1985 at 56 mm.
Relative humidity in Bellevue during December averages 92%. The most humid December was 2012 at 98%, and the least humid was 2009 at 84%.
December receives about 0.9 kWh/m²/day of solar energy in Bellevue. The sunniest Decembers were 1985 and 2009 at 1.1 kWh/m²/day, and the cloudiest were 2012, 2015 and 2019, among others at 0.7.
Average wind speed in Bellevue during December is 0.3 m/s. The windiest Decembers were 1985 and 2013 at 0.4 m/s, while the calmest was 2024 at 0.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 0.3°C | 0.9°C | 1.2°C | 1.0°C | 2.0°C | +1.7°C |
| Avg High | 3.2°C | 3.4°C | 3.7°C | 3.4°C | 4.4°C | +1.2°C |
| Avg Low | -2.5°C | -1.6°C | -1.3°C | -1.4°C | -0.3°C | +2.2°C |
| Avg Rain | 203 mm | 267 mm | 215 mm | 243 mm | 308 mm | +106 mm |
December temperatures in Bellevue have risen by about 2.4°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -21.9°C (1990) to a record high of 14°C (2005).
Rainfall in December is a relatively wet time of year, averaging 243 mm, with a wettest year of 517 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.5°C per decade, narrowing the gap between day and night.
A quieter season to visit Bellevue
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Bellevue. That said, December — with days averaging 3.5°C and nights around -1.5°C (mean 1°C) and higher rainfall (243 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 🌧️ | 5.4°C | 3.3°C | 1.3°C | 11.8°C | -4.0°C | 517 mm | 97% | 0.3 m/s | — |
| 2024 | 4.6°C | 2.4°C | 0.2°C | 7.5°C | -3.8°C | 276 mm | 94% | 0.2 m/s | 0.9 |
| 2023 🔥 | 7.1°C | 4.5°C | 2.0°C | 12.7°C | -2.0°C | 290 mm | 91% | 0.3 m/s | 0.8 |
| 2022 | 2.0°C | -0.5°C | -3.0°C | 10.0°C | -15.9°C | 247 mm | 96% | 0.3 m/s | 0.8 |
| 2021 | 1.6°C | -0.7°C | -2.9°C | 10.4°C | -13.0°C | 263 mm | 96% | 0.3 m/s | 0.8 |
| 2020 | 5.4°C | 2.9°C | 0.4°C | 9.8°C | -3.8°C | 257 mm | 92% | 0.3 m/s | 0.9 |
| 2019 | 4.9°C | 2.8°C | 0.7°C | 8.8°C | -4.2°C | 246 mm | 94% | 0.3 m/s | 0.7 |
| 2018 | 4.3°C | 1.9°C | -0.4°C | 9.9°C | -4.9°C | 274 mm | 91% | 0.3 m/s | 0.9 |
| 2017 | 3.4°C | 0.6°C | -2.3°C | 7.5°C | -9.2°C | 208 mm | 90% | 0.3 m/s | 1 |
| 2016 | 0.4°C | -2.0°C | -4.4°C | 3.9°C | -13.0°C | 216 mm | 96% | 0.3 m/s | 0.9 |
| 2015 | 3.3°C | 1.3°C | -0.7°C | 11.7°C | -8.7°C | 401 mm | 96% | 0.3 m/s | 0.7 |
| 2014 | 5.3°C | 2.5°C | -0.4°C | 13.1°C | -13.7°C | 211 mm | 90% | 0.3 m/s | 1 |
| 2013 | 2.1°C | -0.5°C | -3.1°C | 8.1°C | -16.3°C | 171 mm | 90% | 0.4 m/s | 0.9 |
| 2012 | 2.3°C | 0.3°C | -1.7°C | 7.4°C | -7.5°C | 295 mm | 98% | 0.3 m/s | 0.7 |
| 2011 | 4.2°C | 1.5°C | -1.2°C | 8.9°C | -6.2°C | 148 mm | 90% | 0.3 m/s | 1 |
| 2010 | 3.5°C | 1.4°C | -0.8°C | 9.4°C | -12.4°C | 257 mm | 92% | 0.3 m/s | 0.8 |
| 2009 | 2.7°C | -0.2°C | -3.2°C | 9.4°C | -11.8°C | 112 mm | 84% | 0.3 m/s | 1.1 |
| 2008 | 1.4°C | -1.4°C | -4.1°C | 11.4°C | -19.7°C | 234 mm | 93% | 0.3 m/s | 0.8 |
| 2007 | 2.8°C | 0.8°C | -1.2°C | 11.1°C | -7.4°C | 356 mm | 96% | 0.3 m/s | 0.7 |
| 2006 | 3.6°C | 1.1°C | -1.3°C | 8.8°C | -7.6°C | 233 mm | 94% | 0.3 m/s | 0.8 |
| 2005 | 3.5°C | 1.0°C | -1.4°C | 14.0°C | -8.3°C | 226 mm | 93% | 0.3 m/s | 0.9 |
| 2004 | 6.0°C | 3.4°C | 0.9°C | 12.3°C | -2.5°C | 205 mm | 93% | 0.3 m/s | 0.8 |
| 2003 | 4.0°C | 1.8°C | -0.4°C | 8.5°C | -9.9°C | 184 mm | 93% | 0.3 m/s | 0.8 |
| 2002 | 5.9°C | 3.3°C | 0.7°C | 12.4°C | -2.5°C | 202 mm | 89% | 0.3 m/s | 0.7 |
| 2001 | 3.5°C | 1.1°C | -1.3°C | 6.2°C | -4.6°C | 270 mm | 92% | 0.3 m/s | 0.9 |
| 2000 | 3.4°C | 0.7°C | -2.0°C | 7.3°C | -8.4°C | 129 mm | 90% | 0.3 m/s | 0.9 |
| 1999 | 4.9°C | 2.6°C | 0.3°C | 8.6°C | -2.5°C | 286 mm | 93% | 0.3 m/s | 0.8 |
| 1998 | 2.5°C | 0.1°C | -2.2°C | 9.2°C | -15.1°C | 380 mm | 92% | 0.3 m/s | 0.8 |
| 1997 | 4.6°C | 2.2°C | -0.2°C | 8.0°C | -4.8°C | 168 mm | 90% | 0.3 m/s | 1 |
| 1996 | 2.6°C | 0.2°C | -2.3°C | 10.0°C | -9.6°C | 416 mm | 95% | 0.3 m/s | 0.8 |
| 1995 | 4.0°C | 1.5°C | -1.1°C | 8.2°C | -9.6°C | 259 mm | 89% | 0.3 m/s | 0.8 |
| 1994 | 3.1°C | 0.8°C | -1.6°C | 9.7°C | -10.3°C | 308 mm | 93% | 0.3 m/s | 0.9 |
| 1993 | 5.3°C | 2.4°C | -0.5°C | 10.6°C | -4.0°C | 196 mm | 87% | 0.3 m/s | 0.8 |
| 1992 | 1.4°C | -1.0°C | -3.3°C | 4.7°C | -10.1°C | 216 mm | 92% | 0.3 m/s | 0.9 |
| 1991 | 4.6°C | 2.5°C | 0.5°C | 8.1°C | -3.8°C | 203 mm | 92% | 0.3 m/s | 0.9 |
| 1990 | 0.6°C | -2.4°C | -5.4°C | 8.0°C | -21.9°C | 242 mm | 91% | 0.3 m/s | 0.8 |
| 1989 | 6.4°C | 3.5°C | 0.7°C | 12.3°C | -4.4°C | 183 mm | 90% | 0.3 m/s | 0.9 |
| 1988 | 4.6°C | 1.6°C | -1.4°C | 10.7°C | -9.8°C | 175 mm | 92% | 0.3 m/s | 0.8 |
| 1987 | 2.4°C | -0.5°C | -3.3°C | 8.7°C | -8.9°C | 266 mm | 94% | 0.3 m/s | 0.8 |
| 1986 | 4.5°C | 1.5°C | -1.4°C | 7.7°C | -4.7°C | 157 mm | 90% | 0.3 m/s | 0.8 |
| 1985 | 3.9°C | 0.5°C | -2.8°C | 8.6°C | -17.2°C | 56 mm | 84% | 0.4 m/s | 1.1 |
| 1984 | 0.9°C | -1.9°C | -4.7°C | 4.8°C | -15.3°C | 238 mm | 94% | 0.3 m/s | 1 |
| 1983 ❄️ | -0.4°C | -3.4°C | -6.3°C | 4.8°C | -19.3°C | 190 mm | 89% | 0.3 m/s | — |
| 1982 | 3.3°C | 0.6°C | -2.1°C | 9.8°C | -7.8°C | 285 mm | 93% | 0.3 m/s | — |
| 1981 | 3.2°C | 1.0°C | -1.3°C | 7.5°C | -9.1°C | 273 mm | 94% | 0.3 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 3.5°C with lows near -1.5°C (mean 1°C), based on 45 years of NASA POWER data.
December averages 243 mm of rainfall in Bellevue, a relatively wet time of year. The wettest on record was 517 mm in 2025.
The hottest December reached 14°C in 2005. The coldest dipped to -21.9°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 2.4°C. Daytime highs moved from 2.2°C to 4.1°C and overnight lows from -3.4°C to -0.5°C over the same span.
December is one of the cooler months of the year in Bellevue and a relatively wet time of year, so plan for around 3.5°C daytime highs and -1.5°C at night.
Yes — December is the coldest month of the year in Bellevue, averaging 1°C.
For December in Bellevue, pack warm layers and a jacket for chilly mornings, with typical highs of 3.5°C and lows of -1.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 92% — quite humid.
Average wind speed in December is 0.3 m/s. The windiest December on record averaged 0.4 m/s (1985).
The wettest December on record was 2025 with 517 mm. On average, December sees 243 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 Bellevue 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.
