Weather on September 5
Boulder, CO
55 Years of Data
Avg High
84°F
Avg Low
53°F
Warmest
2019
80°F avg
Coldest
2008
57°F avg
About This Date
September 5th in Boulder, CO typically brings warm fall weather, with average highs around 84°F and lows near 53°F — a 31°F daily swing. Over 55 years of records, the warmest September 5th was in 2019 (80°F average), while the coldest was 2008 (57°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 18% of September 5th dates historically, with the wettest September 5th recording 2.29" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for September 5th in Boulder, CO? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
0.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 64° | 50° | 57° | — | — |
| 2024 | 75° | 54° | 64° | — | — |
| 2023 | 79° | 55° | 67° | — | — |
| 2022 | 97° | 59° | 78° | — | — |
| 2021 | 86° | 59° | 73° | — | — |
| 2020 | 99° | 59° | 79° | — | — |
| 2019warmest | 97° | 63° | 80° | — | — |
| 2018 | 66° | 55° | 61° | — | — |
| 2017 | 79° | 56° | 67° | — | — |
| 2016 | 89° | 50° | 70° | — | — |
| 2015 | 88° | 60° | 74° | 0.03" | — |
| 2014 | 66° | 49° | 57° | 2.29" | — |
| 2013 | 94° | 59° | 76° | — | — |
| 2012 | 88° | 50° | 69° | — | — |
| 2011 | 87° | 45° | 66° | — | — |
| 2010 | 93° | 64° | 79° | — | — |
| 2009 | 85° | 49° | 67° | — | — |
| 2008coldest | 70° | 45° | 57° | 0.18" | — |
| 2007 | 83° | 58° | 70° | 0.1" | — |
| 2006 | 80° | 45° | 62° | — | — |
| 2005 | 90° | 59° | 74° | 0.03" | — |
| 2004 | 71° | 48° | 60° | 0.23" | — |
| 2003 | 87° | 54° | 70° | — | — |
| 2002 | 92° | 58° | 75° | — | — |
| 2001 | 86° | 53° | 70° | — | — |
| 2000 | 92° | 55° | 73° | — | — |
| 1999 | 76° | 46° | 61° | — | — |
| 1998 | 93° | 57° | 75° | — | — |
| 1997 | 82° | 52° | 67° | — | — |
| 1996 | 89° | 54° | 71° | — | — |
| 1995 | 92° | 58° | 75° | — | — |
| 1994 | 85° | 53° | 69° | — | — |
| 1993 | 67° | 49° | 58° | 0.15" | — |
| 1992 | 77° | 49° | 63° | — | — |
| 1991 | 79° | 55° | 67° | — | — |
| 1990 | 86° | 59° | 73° | — | — |
| 1989 | 83° | 48° | 65° | — | — |
| 1988 | 86° | 45° | 65° | — | — |
| 1987 | 73° | 47° | 60° | — | — |
| 1986 | 83° | 54° | 68° | — | — |
| 1985 | 87° | 51° | 69° | 0.3" | — |
| 1984 | 93° | 47° | 70° | — | — |
| 1983 | 86° | 51° | 69° | — | — |
| 1982 | 76° | 59° | 67° | 0.51" | — |
| 1981 | 82° | 53° | 68° | 0.18" | — |
| 1980 | 89° | 55° | 72° | — | — |
| 1979 | 87° | 47° | 67° | — | — |
| 1978 | 92° | 55° | 73° | — | — |
| 1977 | 87° | 51° | 69° | — | — |
| 1976 | 91° | 56° | 73° | — | — |
| 1975 | 76° | 47° | 61° | — | — |
| 1974 | 86° | 54° | 70° | — | — |
| 1973 | 77° | 45° | 61° | — | — |
| 1972 | 81° | 56° | 68° | — | — |
| 1971 | 80° | 45° | 62° | — | — |
55 years of data from BOULDER MUNI AP