Weather on December 15
Longmont, CO
55 Years of Data
Avg High
46°F
Avg Low
16°F
Warmest
2006
56°F avg
Coldest
2008
-4°F avg
About This Date
December 15th in Longmont, CO typically brings chilly winter weather, with average highs around 46°F and lows near 16°F — a 30°F daily swing. Over 55 years of records, the warmest December 15th was in 2006 (56°F average), while the coldest was 2008 (-4°F) — a 60°F range across recorded history. Precipitation has occurred on 9% of recorded December 15th dates, with snow falling 7% of the time (heaviest snowfall: 11.3"). The last decade has been 1.9°F cooler on this date compared to 20-30 years ago.
The last decade has been 1.9°F cooler on this date compared to 20-30 years ago.
Planning for December 15th in Longmont, CO? Bring layers as temperatures can vary throughout the day.
Warming Trend
1.9°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 56° | 22° | 39° | — | — |
| 2024 | 52° | 28° | 40° | — | — |
| 2023 | 36° | 22° | 29° | — | — |
| 2022 | 38° | 15° | 26° | — | — |
| 2021 | 56° | 27° | 41° | — | — |
| 2020 | 36° | 11° | 23° | 0.15" | 0.8" |
| 2019 | 35° | 21° | 28° | — | — |
| 2018 | 54° | 18° | 36° | — | — |
| 2017 | 62° | 19° | 41° | — | — |
| 2016 | 65° | 13° | 39° | — | — |
| 2015 | 31° | 20° | 25° | 1.88" | 11.3" |
| 2014 | 44° | 26° | 35° | — | — |
| 2013 | 56° | 28° | 42° | — | — |
| 2012 | 46° | 28° | 37° | — | — |
| 2011 | 40° | 20° | 30° | — | — |
| 2010 | 58° | 34° | 46° | 0.05" | — |
| 2009 | 52° | 19° | 35° | — | — |
| 2008coldest | 7° | -15° | -4° | — | — |
| 2007 | 37° | 3° | 20° | — | — |
| 2006warmest | 70° | 43° | 56° | — | — |
| 2005 | 38° | 16° | 27° | — | — |
| 2004 | 52° | 34° | 43° | — | — |
| 2003 | 63° | 31° | 47° | — | — |
| 2002 | 55° | 25° | 40° | — | — |
| 2001 | 50° | 16° | 33° | — | — |
| 2000 | 45° | 22° | 33° | — | — |
| 1999 | 40° | 21° | 30° | — | — |
| 1998 | 60° | 15° | 38° | — | — |
| 1997 | 57° | 17° | 37° | — | — |
| 1996 | 49° | 17° | 33° | — | — |
| 1995 | 57° | 13° | 35° | — | — |
| 1994 | 46° | 9° | 27° | — | — |
| 1993 | 54° | 11° | 32° | — | — |
| 1992 | 30° | 2° | 16° | — | — |
| 1991 | 54° | 16° | 35° | — | — |
| 1990 | 40° | 15° | 27° | — | — |
| 1989 | 46° | 2° | 24° | — | — |
| 1988 | 35° | 10° | 23° | 1.12" | 5" |
| 1987 | 28° | -9° | 10° | — | — |
| 1986 | 46° | 14° | 30° | — | — |
| 1985 | 41° | 6° | 24° | — | — |
| 1984 | 24° | -2° | 11° | — | — |
| 1983 | 43° | 20° | 31° | 0.03" | 0.3" |
| 1982 | 45° | 17° | 31° | — | — |
| 1981 | 49° | 20° | 34° | — | — |
| 1980 | 59° | 25° | 42° | — | — |
| 1979 | 52° | 11° | 31° | — | — |
| 1978 | 45° | 12° | 28° | — | — |
| 1977 | 61° | 34° | 47° | — | — |
| 1976 | 50° | 19° | 35° | — | — |
| 1975 | 21° | 2° | 11° | — | — |
| 1974 | 42° | 17° | 30° | — | — |
| 1973 | 48° | 24° | 36° | — | — |
| 1972 | 27° | -13° | 7° | — | — |
| 1971 | 34° | 5° | 19° | — | — |
55 years of data from LONGMONT 2 ESE