Weather on August 20
Boulder, CO
55 Years of Data
Avg High
86°F
Avg Low
56°F
Warmest
2019
80°F avg
Coldest
1979
59°F avg
About This Date
August 20th in Boulder, CO typically brings warm summer weather, with average highs around 86°F and lows near 56°F — a 30°F daily swing. Over 55 years of records, the warmest August 20th was in 2019 (80°F average), while the coldest was 1979 (59°F) — a 21°F range across recorded history. Rain or other precipitation has occurred on about 36% of August 20th dates historically, with the wettest August 20th recording 4.19" of rain. The last decade has been 1.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.4°F warmer on this date compared to 20-30 years ago.
Planning for August 20th in Boulder, CO? Stay hydrated and seek shade during peak afternoon hours. Consider bringing rain gear or an umbrella.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 95° | 59° | 77° | — | — |
| 2024 | 95° | 61° | 78° | — | — |
| 2023 | 90° | 61° | 75° | — | — |
| 2022 | 79° | 59° | 69° | 0.05" | — |
| 2021 | 79° | 52° | 65° | 0.2" | — |
| 2020 | 84° | 61° | 72° | — | — |
| 2019warmest | 97° | 63° | 80° | — | — |
| 2018 | 77° | 52° | 64° | — | — |
| 2017 | 89° | 61° | 75° | — | — |
| 2016 | 76° | 43° | 59° | — | — |
| 2015 | 89° | 47° | 68° | — | — |
| 2014 | 89° | 57° | 73° | 0.03" | — |
| 2013 | 97° | 61° | 79° | — | — |
| 2012 | 84° | 52° | 68° | — | — |
| 2011 | 86° | 53° | 70° | 0.38" | — |
| 2010 | 87° | 58° | 72° | 0.08" | — |
| 2009 | 82° | 48° | 65° | — | — |
| 2008 | 85° | 51° | 68° | — | — |
| 2007 | 96° | 63° | 79° | — | — |
| 2006 | 84° | 53° | 69° | — | — |
| 2005 | 85° | 54° | 69° | 0.03" | — |
| 2004 | 76° | 47° | 61° | 0.23" | — |
| 2003 | 94° | 57° | 75° | — | — |
| 2002 | 86° | 56° | 71° | — | — |
| 2001 | 86° | 64° | 75° | 0.1" | — |
| 2000 | 87° | 56° | 71° | 0.2" | — |
| 1999 | 85° | 56° | 70° | 0.18" | — |
| 1998 | 83° | 61° | 72° | — | — |
| 1997 | 80° | 55° | 68° | — | — |
| 1996 | 86° | 50° | 68° | 0.13" | — |
| 1995 | 87° | 55° | 71° | — | — |
| 1994 | 80° | 50° | 65° | 0.1" | — |
| 1993 | 88° | 55° | 71° | — | — |
| 1992 | 88° | 54° | 71° | — | — |
| 1991 | 82° | 55° | 69° | 0.05" | — |
| 1990 | 80° | 51° | 66° | — | — |
| 1989 | 76° | 48° | 62° | 0.41" | — |
| 1988 | 94° | 53° | 73° | — | — |
| 1987 | 94° | 61° | 77° | — | — |
| 1986 | 80° | 63° | 71° | — | — |
| 1985 | 94° | 53° | 73° | — | — |
| 1984 | 82° | 60° | 71° | 1.3" | — |
| 1983 | 89° | 58° | 73° | 0.03" | — |
| 1982 | 84° | 61° | 72° | 4.19" | — |
| 1981 | 83° | 53° | 68° | 0.08" | — |
| 1980 | 81° | 52° | 66° | — | — |
| 1979coldest | 70° | 48° | 59° | 0.15" | — |
| 1978 | 88° | 53° | 70° | — | — |
| 1977 | 80° | 52° | 66° | 0.08" | — |
| 1976 | 87° | 56° | 71° | — | — |
| 1975 | 86° | 57° | 72° | — | — |
| 1974 | 90° | 64° | 77° | — | — |
| 1973 | 95° | 59° | 77° | — | — |
| 1972 | 82° | 58° | 70° | — | — |
| 1971 | 86° | 57° | 72° | — | — |
55 years of data from BOULDER MUNI AP