Weather on December 18
Boulder, CO
55 Years of Data
Avg High
45°F
Avg Low
21°F
Warmest
2013
57°F avg
Coldest
1996
6°F avg
About This Date
December 18th in Boulder, CO typically brings chilly winter weather, with average highs around 45°F and lows near 21°F. Over 55 years of records, the warmest December 18th was in 2013 (57°F average), while the coldest was 1996 (6°F) — a 51°F range across recorded history. Precipitation has occurred on 13% of recorded December 18th dates, with snow falling 15% of the time (heaviest snowfall: 4.9"). The last decade has been 3.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.0°F warmer on this date compared to 20-30 years ago.
Planning for December 18th in Boulder, CO? Bring layers as temperatures can vary throughout the day.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 50° | 32° | 41° | — | — |
| 2024 | 61° | 27° | 44° | — | — |
| 2023 | 52° | 27° | 40° | — | — |
| 2022 | 41° | 14° | 28° | — | — |
| 2021 | 37° | 12° | 25° | — | — |
| 2020 | 41° | 25° | 33° | — | — |
| 2019 | 52° | 23° | 38° | — | — |
| 2018 | 55° | 30° | 43° | — | — |
| 2017 | 54° | 21° | 37° | — | — |
| 2016 | 26° | -10° | 8° | — | — |
| 2015 | 55° | 6° | 31° | — | — |
| 2014 | 44° | 22° | 33° | — | — |
| 2013warmest | 68° | 46° | 57° | — | — |
| 2012 | 41° | 29° | 35° | — | — |
| 2011 | 61° | 25° | 43° | — | — |
| 2010 | 37° | 13° | 25° | — | — |
| 2009 | 44° | 26° | 35° | — | — |
| 2008 | 31° | 15° | 23° | — | — |
| 2007 | 50° | 28° | 39° | — | — |
| 2006 | 32° | 18° | 25° | 0.03" | 0.1" |
| 2005 | 16° | 7° | 11° | 0.08" | 1.1" |
| 2004 | 48° | 28° | 38° | — | — |
| 2003 | 46° | 21° | 34° | — | — |
| 2002 | 45° | 22° | 33° | 0.03" | 0.2" |
| 2001 | 54° | 29° | 41° | — | — |
| 2000 | 36° | 21° | 28° | — | — |
| 1999 | 41° | 35° | 38° | — | — |
| 1998 | 58° | 19° | 38° | — | 0.1" |
| 1997 | 50° | 31° | 40° | — | — |
| 1996coldest | 18° | -6° | 6° | — | — |
| 1995 | 30° | 23° | 27° | 0.03" | 0.1" |
| 1994 | 61° | 29° | 45° | — | — |
| 1993 | 42° | 14° | 28° | — | — |
| 1992 | 35° | 14° | 25° | 0.05" | 0.5" |
| 1991 | 35° | 20° | 27° | — | — |
| 1990 | 42° | 22° | 32° | — | — |
| 1989 | 23° | -2° | 11° | 0.28" | 1" |
| 1988 | 63° | 30° | 46° | — | — |
| 1987 | 41° | 25° | 33° | — | — |
| 1986 | 49° | 18° | 33° | — | — |
| 1985 | 51° | 22° | 36° | — | — |
| 1984 | 38° | 9° | 23° | — | — |
| 1983 | 17° | 2° | 9° | — | — |
| 1982 | 56° | 34° | 45° | — | — |
| 1981 | 37° | 12° | 25° | — | — |
| 1980 | 64° | 31° | 47° | — | — |
| 1979 | 69° | 42° | 56° | — | — |
| 1978 | 33° | 16° | 24° | — | — |
| 1977 | 54° | 42° | 48° | — | — |
| 1976 | 61° | 33° | 47° | — | — |
| 1975 | 47° | 3° | 25° | — | — |
| 1974 | 47° | 23° | 35° | — | — |
| 1973 | 47° | 15° | 31° | 0.97" | 4.9" |
| 1972 | 54° | 36° | 45° | — | — |
| 1971 | 53° | 29° | 41° | — | — |
55 years of data from BOULDER MUNI AP