Weather on May 9
Boulder, CO
55 Years of Data
Avg High
68°F
Avg Low
41°F
Warmest
2011
69°F avg
Coldest
1979
36°F avg
About This Date
May 9th in Boulder, CO typically brings mild spring weather, with average highs around 68°F and lows near 41°F — a 27°F daily swing. Over 55 years of records, the warmest May 9th was in 2011 (69°F average), while the coldest was 1979 (36°F) — a 33°F range across recorded history. Precipitation has occurred on 36% of recorded May 9th dates, with snow falling 2% of the time (heaviest snowfall: 3"). The last decade has been 2.1°F cooler on this date compared to 20-30 years ago.
The last decade has been 2.1°F cooler on this date compared to 20-30 years ago.
Planning for May 9th in Boulder, CO? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Cooling Trend
0.6°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 73° | 45° | 59° | — | — |
| 2024 | 54° | 43° | 48° | — | — |
| 2023 | 75° | 45° | 60° | — | — |
| 2022 | 72° | 45° | 58° | — | — |
| 2021 | 50° | 37° | 44° | 0.38" | — |
| 2020 | 61° | 43° | 52° | — | — |
| 2019 | 39° | 32° | 36° | — | — |
| 2018 | 75° | 52° | 63° | — | — |
| 2017 | 62° | 46° | 54° | 1.65" | — |
| 2016 | 67° | 37° | 52° | 0.15" | — |
| 2015 | 49° | 39° | 44° | 4.17" | — |
| 2014 | 65° | 34° | 49° | 0.25" | — |
| 2013 | 60° | 41° | 51° | 1.19" | — |
| 2012 | 76° | 39° | 57° | — | — |
| 2011warmest | 83° | 55° | 69° | — | — |
| 2010 | 70° | 33° | 51° | — | — |
| 2009 | 58° | 37° | 47° | — | — |
| 2008 | 74° | 37° | 55° | — | — |
| 2007 | 73° | 40° | 56° | 0.03" | — |
| 2006 | 63° | 43° | 53° | — | — |
| 2005 | 73° | 38° | 55° | — | — |
| 2004 | 87° | 49° | 68° | — | — |
| 2003 | 55° | 36° | 45° | 0.38" | — |
| 2002 | 62° | 25° | 43° | — | — |
| 2001 | 78° | 47° | 62° | — | — |
| 2000 | 71° | 36° | 53° | 0.25" | — |
| 1999 | 78° | 45° | 61° | — | — |
| 1998 | 61° | 33° | 47° | 0.61" | — |
| 1997 | 69° | 37° | 53° | — | — |
| 1996 | 74° | 47° | 60° | 0.56" | — |
| 1995 | 63° | 43° | 53° | — | — |
| 1994 | 68° | 44° | 56° | 0.33" | — |
| 1993 | 55° | 35° | 45° | — | — |
| 1992 | 78° | 49° | 63° | 0.05" | — |
| 1991 | 81° | 50° | 65° | — | — |
| 1990 | 60° | 31° | 45° | — | — |
| 1989 | 67° | 47° | 57° | 1.17" | — |
| 1988 | 71° | 37° | 54° | — | — |
| 1987 | 83° | 49° | 66° | — | — |
| 1986 | 61° | 38° | 49° | 0.1" | — |
| 1985 | 83° | 52° | 67° | — | — |
| 1984 | 83° | 39° | 61° | — | — |
| 1983 | 82° | 40° | 61° | — | — |
| 1982 | 79° | 45° | 62° | — | — |
| 1981 | 52° | 37° | 44° | 0.33" | — |
| 1980 | 69° | 40° | 54° | — | — |
| 1979coldest | 43° | 30° | 36° | 3.3" | 3" |
| 1978 | 64° | 34° | 49° | — | — |
| 1977 | 78° | 48° | 63° | — | — |
| 1976 | 64° | 40° | 52° | 0.25" | — |
| 1975 | 69° | 36° | 52° | — | — |
| 1974 | 83° | 48° | 65° | — | — |
| 1973 | 74° | 44° | 59° | — | — |
| 1972 | 63° | 42° | 52° | 0.03" | — |
| 1971 | 60° | 41° | 51° | 0.03" | — |
55 years of data from BOULDER MUNI AP