December is one of the cooler months of the year in Spanaway, with average highs near 5.1°C and lows around -0.1°C (mean 2.5°C). It is a relatively wet time of year, averaging 226 mm of rainfall and 93% relative humidity across the period.
December is one of the cooler months of the year in Spanaway. Across 45 years of records, the warmest December in Spanaway was 2023 — when the month averaged 5.9°C — while the coldest was 1983 at -1.5°C. Typical December days reach 5.1°C with nights near -0.1°C. The long-term trend is warming, about 0.4°C per decade.
December is a relatively wet time of year in Spanaway, averaging 226 mm of rainfall. The wettest December on record was 2015 with 436 mm, while the driest was 1985 at 64 mm.
Relative humidity in Spanaway during December averages 93%. The most humid Decembers were 2012 and 2021 at 97%, and the least humid was 2009 at 85%.
December receives about 0.9 kWh/m²/day of solar energy in Spanaway. 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 Spanaway during December is 0.3 m/s. The windiest Decembers were 1985, 1993 and 2013 at 0.4 m/s, while the calmest were 2023, 2024 and 2025, among others at 0.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 1.7°C | 2.3°C | 2.5°C | 2.6°C | 3.7°C | +2°C |
| Avg High | 4.6°C | 4.9°C | 5.1°C | 5.0°C | 6.1°C | +1.5°C |
| Avg Low | -1.2°C | -0.3°C | -0.1°C | 0.1°C | 1.3°C | +2.5°C |
| Avg Rain | 188 mm | 246 mm | 206 mm | 226 mm | 286 mm | +99 mm |
December temperatures in Spanaway have risen by about 2.8°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -19.4°C (1990) to a record high of 14°C (2005).
Rainfall in December is a relatively wet time of year, averaging 226 mm, with a wettest year of 436 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.3°C per decade while lows rose 0.6°C per decade, narrowing the gap between day and night.
A quieter season to visit Spanaway
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Spanaway. That said, December — with days averaging 5.1°C and nights around -0.1°C (mean 2.5°C) and higher rainfall (226 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 | 7.4°C | 5.2°C | 3.0°C | 13.1°C | -1.7°C | 410 mm | 97% | 0.3 m/s | — |
| 2024 | 6.8°C | 4.4°C | 2.0°C | 9.9°C | -2.2°C | 284 mm | 95% | 0.3 m/s | 0.9 |
| 2023 🔥 | 8.5°C | 5.9°C | 3.3°C | 13.4°C | -1.6°C | 292 mm | 93% | 0.3 m/s | 0.8 |
| 2022 | 3.7°C | 1.4°C | -1.0°C | 11.6°C | -10.9°C | 249 mm | 95% | 0.3 m/s | 0.8 |
| 2021 | 3.0°C | 1.0°C | -1.1°C | 12.0°C | -12.3°C | 257 mm | 97% | 0.3 m/s | 0.8 |
| 2020 | 7.0°C | 4.4°C | 1.8°C | 11.7°C | -2.2°C | 226 mm | 93% | 0.3 m/s | 0.9 |
| 2019 | 6.3°C | 4.1°C | 1.8°C | 11.1°C | -2.6°C | 238 mm | 96% | 0.3 m/s | 0.7 |
| 2018 | 6.1°C | 3.6°C | 1.1°C | 11.1°C | -4.3°C | 244 mm | 92% | 0.3 m/s | 0.9 |
| 2017 | 5.3°C | 2.4°C | -0.6°C | 9.2°C | -6.8°C | 188 mm | 93% | 0.3 m/s | 1 |
| 2016 | 2.1°C | 0.0°C | -2.1°C | 6.1°C | -8.4°C | 179 mm | 94% | 0.3 m/s | 0.9 |
| 2015 🌧️ | 5.1°C | 3.1°C | 1.1°C | 13.1°C | -6.1°C | 436 mm | 96% | 0.3 m/s | 0.7 |
| 2014 | 7.0°C | 4.2°C | 1.5°C | 13.2°C | -8.3°C | 207 mm | 92% | 0.3 m/s | 1 |
| 2013 | 3.4°C | 0.7°C | -1.9°C | 9.1°C | -13.4°C | 118 mm | 89% | 0.4 m/s | 0.9 |
| 2012 | 4.2°C | 2.2°C | 0.2°C | 8.9°C | -5.0°C | 276 mm | 97% | 0.3 m/s | 0.7 |
| 2011 | 5.3°C | 2.5°C | -0.3°C | 9.7°C | -4.4°C | 118 mm | 92% | 0.3 m/s | 1 |
| 2010 | 5.5°C | 3.0°C | 0.6°C | 11.3°C | -8.4°C | 253 mm | 94% | 0.3 m/s | 0.8 |
| 2009 | 4.3°C | 1.1°C | -2.0°C | 9.9°C | -10.4°C | 114 mm | 85% | 0.3 m/s | 1.1 |
| 2008 | 2.6°C | -0.1°C | -2.8°C | 10.3°C | -14.9°C | 195 mm | 94% | 0.3 m/s | 0.8 |
| 2007 | 4.0°C | 1.9°C | -0.2°C | 12.7°C | -6.3°C | 330 mm | 96% | 0.3 m/s | 0.7 |
| 2006 | 5.2°C | 2.6°C | 0.0°C | 10.7°C | -5.4°C | 235 mm | 94% | 0.3 m/s | 0.8 |
| 2005 | 5.3°C | 2.7°C | 0.2°C | 14.0°C | -6.6°C | 240 mm | 93% | 0.3 m/s | 0.9 |
| 2004 | 7.2°C | 4.5°C | 1.9°C | 13.3°C | -1.2°C | 153 mm | 93% | 0.3 m/s | 0.8 |
| 2003 | 5.3°C | 3.2°C | 1.1°C | 9.8°C | -6.4°C | 189 mm | 94% | 0.3 m/s | 0.8 |
| 2002 | 7.0°C | 4.3°C | 1.6°C | 13.4°C | -2.5°C | 234 mm | 93% | 0.3 m/s | 0.7 |
| 2001 | 5.0°C | 2.4°C | -0.2°C | 8.7°C | -3.9°C | 259 mm | 95% | 0.3 m/s | 0.9 |
| 2000 | 5.4°C | 2.6°C | -0.2°C | 10.2°C | -5.7°C | 107 mm | 92% | 0.3 m/s | 0.9 |
| 1999 | 6.5°C | 4.0°C | 1.5°C | 9.9°C | -1.5°C | 246 mm | 95% | 0.3 m/s | 0.8 |
| 1998 | 4.2°C | 1.9°C | -0.5°C | 10.9°C | -11.9°C | 349 mm | 93% | 0.3 m/s | 0.8 |
| 1997 | 5.9°C | 3.2°C | 0.5°C | 10.3°C | -3.8°C | 146 mm | 92% | 0.3 m/s | 1 |
| 1996 | 4.4°C | 1.9°C | -0.7°C | 11.3°C | -5.1°C | 423 mm | 96% | 0.3 m/s | 0.8 |
| 1995 | 5.8°C | 3.2°C | 0.6°C | 11.4°C | -6.4°C | 258 mm | 93% | 0.3 m/s | 0.8 |
| 1994 | 4.7°C | 2.3°C | -0.2°C | 10.7°C | -9.3°C | 298 mm | 94% | 0.3 m/s | 0.9 |
| 1993 | 6.6°C | 3.7°C | 0.7°C | 12.2°C | -3.9°C | 206 mm | 89% | 0.4 m/s | 0.8 |
| 1992 | 3.1°C | 0.7°C | -1.7°C | 6.4°C | -7.1°C | 182 mm | 93% | 0.3 m/s | 0.9 |
| 1991 | 6.0°C | 3.7°C | 1.4°C | 9.1°C | -3.5°C | 169 mm | 94% | 0.3 m/s | 0.9 |
| 1990 | 1.7°C | -1.2°C | -4.2°C | 8.3°C | -19.4°C | 184 mm | 90% | 0.3 m/s | 0.8 |
| 1989 | 7.5°C | 4.4°C | 1.4°C | 12.7°C | -3.4°C | 156 mm | 92% | 0.3 m/s | 0.9 |
| 1988 | 5.5°C | 2.7°C | -0.1°C | 10.6°C | -7.4°C | 159 mm | 94% | 0.3 m/s | 0.8 |
| 1987 | 3.9°C | 1.1°C | -1.8°C | 11.0°C | -6.8°C | 262 mm | 93% | 0.3 m/s | 0.8 |
| 1986 | 6.1°C | 3.1°C | 0.0°C | 8.8°C | -4.1°C | 153 mm | 93% | 0.3 m/s | 0.8 |
| 1985 | 4.7°C | 1.2°C | -2.3°C | 9.7°C | -17.5°C | 64 mm | 89% | 0.4 m/s | 1.1 |
| 1984 | 2.4°C | -0.3°C | -3.1°C | 5.5°C | -11.0°C | 175 mm | 94% | 0.3 m/s | 1 |
| 1983 ❄️ | 1.5°C | -1.5°C | -4.6°C | 6.4°C | -17.4°C | 186 mm | 90% | 0.3 m/s | — |
| 1982 | 4.7°C | 2.0°C | -0.7°C | 11.1°C | -6.7°C | 267 mm | 95% | 0.3 m/s | — |
| 1981 | 5.1°C | 2.6°C | 0.1°C | 9.9°C | -6.5°C | 269 mm | 96% | 0.3 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 5.1°C with lows near -0.1°C (mean 2.5°C), based on 45 years of NASA POWER data.
December averages 226 mm of rainfall in Spanaway, a relatively wet time of year. The wettest on record was 436 mm in 2015.
The hottest December reached 14°C in 2005. The coldest dipped to -19.4°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 2.8°C. Daytime highs moved from 3.7°C to 5.9°C and overnight lows from -2.1°C to 1.2°C over the same span.
December is one of the cooler months of the year in Spanaway and a relatively wet time of year, so plan for around 5.1°C daytime highs and -0.1°C at night.
Yes — December is the coldest month of the year in Spanaway, averaging 2.5°C.
For December in Spanaway, pack warm layers and a jacket for chilly mornings, with typical highs of 5.1°C and lows of -0.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 93% — quite humid.
Average wind speed in December is 0.3 m/s. The windiest December on record averaged 0.4 m/s (1985).
The wettest December on record was 2015 with 436 mm. On average, December sees 226 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 Spanaway 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.
