Weather on December 18
Boise, ID
55 Years of Data
Avg High
37°F
Avg Low
23°F
Warmest
2024
47°F avg
Coldest
1985
7°F avg
About This Date
December 18th in Boise, ID typically brings cold winter weather, with average highs around 37°F and lows near 23°F. Over 55 years of records, the warmest December 18th was in 2024 (47°F average), while the coldest was 1985 (7°F) — a 40°F range across recorded history. Precipitation has occurred on 35% of recorded December 18th dates, with snow falling 15% of the time (heaviest snowfall: 1.6"). The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
Planning for December 18th in Boise, ID? Bundle up with warm layers and protect extremities from the cold. Consider bringing rain gear or an umbrella.
Warming Trend
0.9°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 48° | 32° | 40° | 0.36" | — |
| 2024warmest | 59° | 36° | 47° | — | — |
| 2023 | 36° | 26° | 31° | — | — |
| 2022 | 21° | 11° | 16° | — | — |
| 2021 | 35° | 25° | 30° | — | — |
| 2020 | 43° | 32° | 37° | — | — |
| 2019 | 35° | 22° | 29° | — | — |
| 2018 | 45° | 38° | 41° | 0.38" | — |
| 2017 | 45° | 29° | 37° | — | — |
| 2016 | 17° | 0° | 9° | — | — |
| 2015 | 43° | 35° | 39° | 0.1" | — |
| 2014 | 47° | 34° | 40° | — | — |
| 2013 | 26° | 21° | 24° | — | — |
| 2012 | 35° | 20° | 27° | — | — |
| 2011 | 38° | 19° | 28° | — | — |
| 2010 | 41° | 29° | 35° | 0.23" | 0.8" |
| 2009 | 45° | 32° | 38° | 0.03" | — |
| 2008 | 34° | 17° | 25° | — | — |
| 2007 | 42° | 36° | 39° | 0.46" | — |
| 2006 | 32° | 16° | 24° | — | — |
| 2005 | 27° | 8° | 17° | 0.03" | 0.5" |
| 2004 | 34° | 28° | 31° | — | — |
| 2003 | 42° | 29° | 35° | — | — |
| 2002 | 41° | 25° | 33° | — | — |
| 2001 | 40° | 27° | 33° | 0.03" | — |
| 2000 | 37° | 20° | 28° | — | — |
| 1999 | 49° | 33° | 41° | 0.03" | — |
| 1998 | 34° | 20° | 27° | — | — |
| 1997 | 39° | 26° | 33° | — | — |
| 1996 | 28° | 14° | 21° | — | — |
| 1995 | 36° | 25° | 30° | — | — |
| 1994 | 45° | 34° | 39° | 0.18" | — |
| 1993 | 41° | 21° | 31° | — | — |
| 1992 | 26° | 5° | 16° | 0.18" | 0.9" |
| 1991 | 53° | 28° | 41° | 0.13" | — |
| 1990 | 44° | 24° | 34° | 0.23" | 1.6" |
| 1989 | 35° | 15° | 25° | — | — |
| 1988 | 38° | 16° | 27° | — | — |
| 1987 | 34° | 18° | 26° | — | — |
| 1986 | 24° | 19° | 22° | 0.1" | 0.4" |
| 1985coldest | 17° | -3° | 7° | — | — |
| 1984 | 19° | -1° | 9° | — | — |
| 1983 | 30° | 24° | 27° | 0.25" | 1" |
| 1982 | 45° | 30° | 37° | — | — |
| 1981 | 41° | 31° | 36° | 0.66" | — |
| 1980 | 30° | 22° | 26° | — | — |
| 1979 | 55° | 25° | 40° | — | — |
| 1978 | 35° | 22° | 28° | 0.15" | 1" |
| 1977 | 39° | 30° | 35° | 0.03" | 0.1" |
| 1976 | 39° | 13° | 26° | — | — |
| 1975 | 24° | 9° | 16° | — | — |
| 1974 | 37° | 25° | 31° | — | — |
| 1973 | 47° | 33° | 40° | — | — |
| 1972 | 48° | 34° | 41° | 0.28" | — |
| 1971 | 32° | 14° | 23° | — | — |
55 years of data from BOISE AIR TERMINAL