Weather on September 17
Denver, CO
55 Years of Data
Avg High
80°F
Avg Low
48°F
Warmest
2019
76°F avg
Coldest
1971
33°F avg
About This Date
September 17th in Denver, CO typically brings warm fall weather, with average highs around 80°F and lows near 48°F — a 32°F daily swing. Over 55 years of records, the warmest September 17th was in 2019 (76°F average), while the coldest was 1971 (33°F) — a 43°F range across recorded history. Precipitation has occurred on 16% of recorded September 17th dates, with snow falling 2% of the time (heaviest snowfall: 12"). The last decade has been 1.1°F cooler on this date compared to 20-30 years ago.
The last decade has been 1.1°F cooler on this date compared to 20-30 years ago.
Planning for September 17th in Denver, CO? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.4°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 82° | 45° | 63° | 1.14" | — |
| 2024 | 86° | 49° | 67° | — | — |
| 2023 | 79° | 41° | 60° | — | — |
| 2022 | 86° | 49° | 67° | — | — |
| 2021 | 96° | 47° | 71° | — | — |
| 2020 | 75° | 47° | 61° | — | — |
| 2019warmest | 91° | 60° | 76° | — | — |
| 2018 | 95° | 56° | 75° | — | — |
| 2017 | 70° | 46° | 58° | — | — |
| 2016 | 74° | 45° | 59° | — | — |
| 2015 | 90° | 49° | 69° | — | — |
| 2014 | 88° | 46° | 67° | — | — |
| 2013 | 74° | 51° | 62° | — | — |
| 2012 | 86° | 51° | 69° | — | — |
| 2011 | 78° | 45° | 61° | — | — |
| 2010 | 89° | 50° | 70° | — | — |
| 2009 | 84° | 51° | 68° | — | — |
| 2008 | 87° | 51° | 69° | — | — |
| 2007 | 72° | 57° | 64° | 0.15" | — |
| 2006 | 66° | 44° | 55° | — | — |
| 2005 | 85° | 45° | 65° | — | — |
| 2004 | 90° | 49° | 69° | — | — |
| 2003 | 91° | 59° | 75° | — | — |
| 2002 | 84° | 53° | 69° | — | — |
| 2001 | 72° | 51° | 61° | 0.28" | — |
| 2000 | 95° | 55° | 75° | — | — |
| 1999 | 83° | 46° | 64° | — | — |
| 1998 | 90° | 52° | 71° | — | — |
| 1997 | 83° | 49° | 66° | — | — |
| 1996 | 62° | 45° | 53° | 0.51" | — |
| 1995 | 78° | 48° | 63° | — | — |
| 1994 | 82° | 46° | 64° | — | — |
| 1993 | 71° | 45° | 58° | 0.25" | — |
| 1992 | 85° | 46° | 65° | — | — |
| 1991 | 69° | 42° | 56° | — | — |
| 1990 | 67° | 52° | 59° | 0.1" | — |
| 1989 | 87° | 54° | 70° | — | — |
| 1988 | 83° | 41° | 62° | — | — |
| 1987 | 56° | 42° | 49° | 0.51" | — |
| 1986 | 81° | 51° | 66° | — | — |
| 1985 | 85° | 57° | 71° | — | — |
| 1984 | 81° | 46° | 63° | — | — |
| 1983 | 91° | 51° | 71° | — | — |
| 1982 | 69° | 47° | 58° | 0.03" | — |
| 1981 | 73° | 38° | 55° | — | — |
| 1980 | 86° | 38° | 62° | — | — |
| 1979 | 84° | 42° | 63° | — | — |
| 1978 | 80° | 58° | 69° | — | — |
| 1977 | 82° | 51° | 67° | — | — |
| 1976 | 83° | 50° | 66° | — | — |
| 1975 | 85° | 50° | 67° | — | — |
| 1974 | 77° | 41° | 59° | — | — |
| 1973 | 67° | 40° | 53° | — | — |
| 1972 | 85° | 50° | 67° | — | — |
| 1971coldest | 35° | 31° | 33° | 2.97" | 12" |
55 years of data from NORTHGLENN