Weather on December 20
Boise, ID
55 Years of Data
Avg High
38°F
Avg Low
23°F
Warmest
2019
45°F avg
Coldest
1990
1°F avg
About This Date
December 20th in Boise, ID typically brings cold winter weather, with average highs around 38°F and lows near 23°F. Over 55 years of records, the warmest December 20th was in 2019 (45°F average), while the coldest was 1990 (1°F) — a 44°F range across recorded history. Precipitation has occurred on 40% of recorded December 20th dates, with snow falling 16% of the time (heaviest snowfall: 9.8"). The last decade has been 6.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 6.5°F warmer on this date compared to 20-30 years ago.
Planning for December 20th in Boise, ID? Bundle up with warm layers and protect extremities from the cold. Consider bringing rain gear or an umbrella.
Warming Trend
2.0°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 45° | 30° | 37° | — | — |
| 2024 | 47° | 33° | 40° | — | — |
| 2023 | 42° | 31° | 37° | — | — |
| 2022 | 38° | 18° | 28° | — | — |
| 2021 | 50° | 30° | 40° | — | — |
| 2020 | 46° | 39° | 43° | 0.08" | — |
| 2019warmest | 50° | 40° | 45° | — | — |
| 2018 | 51° | 31° | 41° | — | — |
| 2017 | 51° | 28° | 40° | 0.28" | 0.3" |
| 2016 | 26° | 15° | 21° | 0.08" | 0.1" |
| 2015 | 40° | 26° | 33° | 0.1" | 0.2" |
| 2014 | 44° | 36° | 40° | 1.8" | — |
| 2013 | 31° | 11° | 21° | 0.51" | 2.3" |
| 2012 | 45° | 33° | 39° | — | — |
| 2011 | 44° | 21° | 33° | — | — |
| 2010 | 42° | 30° | 36° | — | — |
| 2009 | 43° | 30° | 36° | 0.03" | — |
| 2008 | 28° | 15° | 22° | — | — |
| 2007 | 43° | 29° | 36° | 0.13" | — |
| 2006 | 35° | 12° | 24° | — | — |
| 2005 | 35° | 29° | 32° | — | — |
| 2004 | 35° | 26° | 31° | — | — |
| 2003 | 43° | 30° | 36° | 0.15" | — |
| 2002 | 43° | 33° | 38° | — | — |
| 2001 | 46° | 30° | 38° | 0.05" | — |
| 2000 | 36° | 19° | 27° | 0.03" | 0.4" |
| 1999 | 45° | 28° | 36° | — | — |
| 1998 | 18° | 4° | 11° | — | — |
| 1997 | 39° | 23° | 31° | — | — |
| 1996 | 31° | 23° | 27° | 1.8" | 9.8" |
| 1995 | 31° | 20° | 25° | — | — |
| 1994 | 42° | 25° | 33° | — | — |
| 1993 | 33° | 17° | 25° | — | — |
| 1992 | 33° | 23° | 28° | 0.03" | 0.1" |
| 1991 | 38° | 18° | 28° | — | — |
| 1990coldest | 9° | -8° | 1° | 0.18" | 1.1" |
| 1989 | 36° | 16° | 26° | — | — |
| 1988 | 40° | 20° | 30° | 0.08" | — |
| 1987 | 36° | 17° | 26° | — | — |
| 1986 | 26° | 24° | 25° | — | — |
| 1985 | 12° | -1° | 6° | — | — |
| 1984 | 10° | -5° | 3° | 0.2" | 1.5" |
| 1983 | 16° | -6° | 5° | — | — |
| 1982 | 52° | 33° | 42° | 0.48" | — |
| 1981 | 49° | 37° | 43° | 0.3" | — |
| 1980 | 32° | 27° | 29° | — | — |
| 1979 | 50° | 34° | 42° | 0.15" | — |
| 1978 | 37° | 16° | 26° | — | — |
| 1977 | 32° | 21° | 27° | — | — |
| 1976 | 36° | 8° | 22° | — | — |
| 1975 | 23° | 14° | 19° | — | — |
| 1974 | 47° | 36° | 41° | 1.45" | — |
| 1973 | 46° | 32° | 39° | 0.38" | — |
| 1972 | 52° | 35° | 43° | 0.03" | — |
| 1971 | 41° | 16° | 28° | — | — |
55 years of data from BOISE AIR TERMINAL