Weather on December 18
Boulder, CO
55 Years of Data
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° | — | — |
Boulder, CO Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Boulder, CO Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Boulder, CO Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Boulder, CO
Boulder, CO has no months that meet our "pleasant" threshold — every season has tradeoffs.