Weather on May 15
Boulder, CO
55 Years of Data
Avg High
72°F
Avg Low
44°F
Warmest
1978
73°F avg
Coldest
2011
39°F avg
About This Date
May 15th in Boulder, CO typically brings pleasant spring weather, with average highs around 72°F and lows near 44°F — a 28°F daily swing. Over 55 years of records, the warmest May 15th was in 1978 (73°F average), while the coldest was 2011 (39°F) — a 34°F range across recorded history. Rain or other precipitation has occurred on about 35% of May 15th dates historically, with the wettest May 15th recording 1.27" of rain. The last decade has been 3.2°F cooler on this date compared to 20-30 years ago.
The last decade has been 3.2°F cooler on this date compared to 20-30 years ago.
Planning for May 15th in Boulder, CO? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Cooling Trend
0.8°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 64° | 45° | 54° | — | — |
| 2024 | 66° | 45° | 55° | — | — |
| 2023 | 59° | 46° | 53° | — | — |
| 2022 | 77° | 54° | 65° | — | — |
| 2021 | 63° | 46° | 54° | 0.05" | — |
| 2020 | 64° | 50° | 57° | — | — |
| 2019 | 81° | 48° | 64° | — | — |
| 2018 | 72° | 43° | 57° | — | — |
| 2017 | 77° | 46° | 62° | — | — |
| 2016 | 52° | 38° | 45° | 0.3" | — |
| 2015 | 68° | 44° | 56° | 0.43" | — |
| 2014 | 61° | 34° | 47° | — | — |
| 2013 | 80° | 53° | 67° | — | — |
| 2012 | 78° | 43° | 60° | — | — |
| 2011coldest | 45° | 34° | 39° | 0.89" | — |
| 2010 | 61° | 37° | 49° | 0.53" | — |
| 2009 | 69° | 48° | 59° | — | — |
| 2008 | 59° | 41° | 50° | 0.64" | — |
| 2007 | 68° | 45° | 56° | 0.58" | — |
| 2006 | 72° | 39° | 55° | — | — |
| 2005 | 73° | 41° | 57° | — | — |
| 2004 | 67° | 39° | 53° | — | — |
| 2003 | 71° | 44° | 58° | 0.13" | — |
| 2002 | 73° | 44° | 59° | 0.03" | — |
| 2001 | 84° | 55° | 70° | — | — |
| 2000 | 83° | 41° | 62° | — | — |
| 1999 | 70° | 42° | 56° | — | — |
| 1998 | 69° | 39° | 54° | — | — |
| 1997 | 76° | 42° | 59° | 0.1" | — |
| 1996 | 88° | 52° | 70° | — | — |
| 1995 | 82° | 42° | 62° | — | — |
| 1994 | 78° | 45° | 61° | — | — |
| 1993 | 77° | 49° | 63° | 0.79" | — |
| 1992 | 81° | 47° | 64° | — | — |
| 1991 | 80° | 46° | 63° | 1.27" | — |
| 1990 | 66° | 42° | 54° | 0.1" | — |
| 1989 | 66° | 36° | 51° | — | — |
| 1988 | 80° | 46° | 63° | — | — |
| 1987 | 84° | 49° | 66° | — | — |
| 1986 | 67° | 43° | 55° | 0.66" | — |
| 1985 | 72° | 39° | 55° | — | — |
| 1984 | 86° | 49° | 67° | — | — |
| 1983 | 58° | 34° | 46° | 0.2" | — |
| 1982 | 64° | 36° | 50° | — | — |
| 1981 | 72° | 46° | 59° | 0.13" | — |
| 1980 | 56° | 45° | 50° | 0.81" | — |
| 1979 | 75° | 45° | 60° | — | — |
| 1978warmest | 93° | 54° | 73° | — | — |
| 1977 | 67° | 46° | 56° | — | — |
| 1976 | 80° | 41° | 61° | 0.46" | — |
| 1975 | 83° | 44° | 63° | — | — |
| 1974 | 76° | 39° | 57° | — | — |
| 1973 | 73° | 38° | 55° | — | — |
| 1972 | 80° | 51° | 66° | — | — |
| 1971 | 66° | 44° | 55° | 0.28" | — |
55 years of data from BOULDER MUNI AP