Weather on December 31
Boulder, CO
55 Years of Data
Avg High
43°F
Avg Low
18°F
Warmest
1980
50°F avg
Coldest
1978
3°F avg
About This Date
December 31st in Boulder, CO typically brings chilly winter weather, with average highs around 43°F and lows near 18°F — a 25°F daily swing. Over 55 years of records, the warmest December 31st was in 1980 (50°F average), while the coldest was 1978 (3°F) — a 47°F range across recorded history. Precipitation has occurred on 18% of recorded December 31st dates, with snow falling 22% of the time (heaviest snowfall: 8"). The last decade has been 7.3°F cooler on this date compared to 20-30 years ago.
The last decade has been 7.3°F cooler on this date compared to 20-30 years ago.
Planning for December 31st in Boulder, CO? Bring layers as temperatures can vary throughout the day. Check road conditions if traveling, as snow is possible.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 64° | 28° | 46° | — | — |
| 2024 | 36° | 21° | 28° | — | — |
| 2023 | 41° | 27° | 34° | — | — |
| 2022 | 50° | 21° | 36° | — | — |
| 2021 | 45° | 16° | 31° | — | — |
| 2020 | 43° | 21° | 32° | — | — |
| 2019 | 52° | 18° | 35° | — | — |
| 2018 | 37° | 7° | 22° | — | — |
| 2017 | 27° | 12° | 19° | 0.03" | 0.1" |
| 2016 | 50° | 22° | 36° | — | — |
| 2015 | 31° | 6° | 18° | — | — |
| 2014 | 31° | -14° | 8° | — | — |
| 2013 | 57° | 29° | 43° | — | — |
| 2012 | 28° | 10° | 19° | 0.03" | 0.1" |
| 2011 | 59° | 33° | 46° | — | — |
| 2010 | 13° | 2° | 7° | 0.33" | 2.2" |
| 2009 | 38° | 14° | 26° | — | — |
| 2008 | 60° | 15° | 38° | — | — |
| 2007 | 32° | 13° | 22° | — | 0.1" |
| 2006 | 35° | 15° | 25° | — | — |
| 2005 | 65° | 29° | 47° | — | — |
| 2004 | 56° | 34° | 45° | — | — |
| 2003 | 45° | 23° | 34° | — | — |
| 2002 | 58° | 24° | 41° | — | — |
| 2001 | 35° | 13° | 24° | — | — |
| 2000 | 39° | 24° | 32° | 0.03" | 0.1" |
| 1999 | 60° | 26° | 43° | — | — |
| 1998 | 43° | 27° | 35° | — | — |
| 1997 | 63° | 24° | 43° | — | — |
| 1996 | 65° | 32° | 48° | — | — |
| 1995 | 42° | 24° | 33° | 0.1" | 0.2" |
| 1994 | 24° | 13° | 18° | 0.81" | 8" |
| 1993 | 53° | 29° | 41° | — | — |
| 1992 | 38° | 14° | 26° | — | — |
| 1991 | 40° | 19° | 29° | — | — |
| 1990 | 52° | 17° | 34° | — | — |
| 1989 | 35° | 0° | 18° | 0.25" | 1" |
| 1988 | 52° | 19° | 35° | — | — |
| 1987 | 28° | 0° | 14° | — | — |
| 1986 | 43° | 28° | 35° | — | — |
| 1985 | 44° | 19° | 32° | — | — |
| 1984 | 43° | 24° | 33° | 0.05" | 0.3" |
| 1983 | 51° | 31° | 41° | — | — |
| 1982 | 40° | 11° | 25° | — | — |
| 1981 | 48° | 26° | 37° | — | — |
| 1980warmest | 62° | 38° | 50° | — | — |
| 1979 | 52° | 16° | 34° | — | — |
| 1978coldest | 11° | -6° | 3° | — | — |
| 1977 | 48° | 16° | 32° | — | — |
| 1976 | 29° | 1° | 15° | — | — |
| 1975 | 45° | 19° | 32° | 0.51" | 3.7" |
| 1974 | 32° | 17° | 25° | — | 0.1" |
| 1973 | 18° | 0° | 9° | 0.18" | 1.8" |
| 1972 | 35° | 14° | 25° | — | — |
| 1971 | 51° | 22° | 36° | — | — |
55 years of data from BOULDER MUNI AP