Weather on December 9
Boulder, CO
55 Years of Data
Avg High
45°F
Avg Low
21°F
Warmest
1975
55°F avg
Coldest
1978
-6°F avg
About This Date
December 9th 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 9th was in 1975 (55°F average), while the coldest was 1978 (-6°F) — a 61°F range across recorded history. Precipitation has occurred on 13% of recorded December 9th dates, with snow falling 16% of the time (heaviest snowfall: 10.5"). 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 9th in Boulder, CO? Bring layers as temperatures can vary throughout the day.
Warming Trend
1.1°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 61° | 37° | 49° | — | — |
| 2024 | 43° | 27° | 35° | — | — |
| 2023 | 36° | 21° | 29° | — | — |
| 2022 | 50° | 19° | 35° | — | — |
| 2021 | 50° | 34° | 42° | — | — |
| 2020 | 63° | 34° | 48° | — | — |
| 2019 | 43° | 27° | 35° | — | — |
| 2018 | 45° | 25° | 35° | — | — |
| 2017 | 64° | 32° | 48° | — | — |
| 2016 | 48° | 6° | 27° | — | — |
| 2015 | 68° | 42° | 55° | — | — |
| 2014 | 47° | 26° | 36° | — | — |
| 2013 | 25° | -6° | 10° | — | — |
| 2012 | 38° | 14° | 26° | — | — |
| 2011 | 40° | 16° | 28° | — | — |
| 2010 | 59° | 37° | 48° | — | — |
| 2009 | 16° | -12° | 2° | — | 0.1" |
| 2008 | 33° | 16° | 24° | 1.5" | 8.6" |
| 2007 | 25° | 7° | 16° | 0.48" | 3.3" |
| 2006 | 57° | 29° | 43° | — | — |
| 2005 | 44° | 10° | 27° | — | — |
| 2004 | 51° | 30° | 41° | — | — |
| 2003 | 35° | 13° | 24° | 0.69" | 4.5" |
| 2002 | 56° | 22° | 39° | — | — |
| 2001 | 57° | 25° | 41° | — | — |
| 2000 | 54° | 30° | 42° | — | — |
| 1999 | 42° | 10° | 26° | — | — |
| 1998 | 33° | 23° | 28° | 0.94" | 7.1" |
| 1997 | 37° | 28° | 33° | — | 0.1" |
| 1996 | 67° | 37° | 52° | — | — |
| 1995 | 30° | 4° | 17° | — | — |
| 1994 | 38° | 7° | 22° | — | — |
| 1993 | 57° | 39° | 48° | — | — |
| 1992 | 51° | 31° | 41° | — | — |
| 1991 | 48° | 24° | 36° | — | — |
| 1990 | 62° | 35° | 49° | — | — |
| 1989 | 54° | 10° | 32° | — | — |
| 1988 | 46° | 14° | 30° | — | — |
| 1987 | 48° | 24° | 36° | — | — |
| 1986 | 27° | 13° | 20° | 1.19" | 10" |
| 1985 | 28° | 16° | 22° | 2.03" | 10.5" |
| 1984 | 64° | 31° | 47° | — | — |
| 1983 | 42° | 25° | 33° | — | — |
| 1982 | 49° | 14° | 31° | — | — |
| 1981 | 65° | 34° | 49° | — | — |
| 1980 | 43° | 22° | 32° | — | — |
| 1979 | 62° | 31° | 46° | — | — |
| 1978coldest | 7° | -19° | -6° | — | — |
| 1977 | 20° | 1° | 10° | — | — |
| 1976 | 59° | 41° | 50° | — | — |
| 1975warmest | 63° | 48° | 55° | — | — |
| 1974 | 57° | 23° | 40° | — | — |
| 1973 | 42° | 25° | 33° | — | — |
| 1972 | 5° | -4° | 1° | 0.05" | 1" |
| 1971 | 46° | 0° | 23° | — | — |
55 years of data from BOULDER MUNI AP