Weather on September 25
Longmont, CO
55 Years of Data
Avg High
74°F
Avg Low
42°F
Warmest
2011
70°F avg
Coldest
1984
35°F avg
About This Date
September 25th in Longmont, CO typically brings pleasant fall weather, with average highs around 74°F and lows near 42°F — a 32°F daily swing. Over 55 years of records, the warmest September 25th was in 2011 (70°F average), while the coldest was 1984 (35°F) — a 35°F range across recorded history. Precipitation has occurred on 22% of recorded September 25th dates, with snow falling 2% of the time. The last decade has been 2.1°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.1°F warmer on this date compared to 20-30 years ago.
Planning for September 25th in Longmont, CO? Great weather for outdoor activities.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 69° | 42° | 56° | — | — |
| 2024 | 76° | 48° | 62° | — | — |
| 2023 | 75° | 41° | 58° | — | — |
| 2022 | 79° | 44° | 61° | — | — |
| 2021 | 71° | 43° | 57° | — | — |
| 2020 | 89° | 47° | 68° | — | — |
| 2019 | 81° | 45° | 63° | — | — |
| 2018 | 81° | 43° | 62° | — | — |
| 2017 | 49° | 41° | 45° | 0.36" | — |
| 2016 | 69° | 40° | 54° | — | — |
| 2015 | 83° | 47° | 65° | — | — |
| 2014 | 87° | 50° | 69° | — | — |
| 2013 | 78° | 43° | 60° | — | — |
| 2012 | 72° | 48° | 60° | 0.1" | — |
| 2011warmest | 85° | 55° | 70° | — | — |
| 2010 | 78° | 48° | 63° | — | — |
| 2009 | 65° | 43° | 54° | 0.13" | — |
| 2008 | 84° | 45° | 64° | — | — |
| 2007 | 64° | 38° | 51° | 1.09" | — |
| 2006 | 69° | 37° | 53° | — | — |
| 2005 | 69° | 48° | 59° | 0.13" | — |
| 2004 | 74° | 41° | 57° | — | — |
| 2003 | 71° | 36° | 53° | — | — |
| 2002 | 88° | 36° | 62° | — | — |
| 2001 | 83° | 36° | 59° | — | — |
| 2000 | 47° | 24° | 35° | 0.51" | — |
| 1999 | 83° | 49° | 66° | — | — |
| 1998 | 84° | 42° | 63° | — | — |
| 1997 | 70° | 39° | 54° | — | — |
| 1996 | 74° | 40° | 57° | 0.03" | — |
| 1995 | 56° | 30° | 43° | — | — |
| 1994 | 78° | 41° | 60° | — | — |
| 1993 | 67° | 33° | 50° | 0.13" | — |
| 1992 | 90° | 47° | 68° | — | — |
| 1991 | 71° | 37° | 54° | — | — |
| 1990 | 86° | 46° | 66° | — | — |
| 1989 | 82° | 43° | 62° | — | — |
| 1988 | 84° | 37° | 61° | — | — |
| 1987 | 86° | 43° | 64° | — | — |
| 1986 | 63° | 48° | 55° | 0.13" | — |
| 1985 | 59° | 32° | 46° | — | — |
| 1984coldest | 44° | 26° | 35° | 0.23" | 0.3" |
| 1983 | 84° | 45° | 64° | — | — |
| 1982 | 73° | 47° | 60° | — | — |
| 1981 | 76° | 47° | 61° | 0.1" | — |
| 1980 | 71° | 47° | 59° | — | — |
| 1979 | 81° | 48° | 64° | — | — |
| 1978 | 78° | 46° | 62° | — | — |
| 1977 | 85° | 34° | 59° | — | — |
| 1976 | 66° | 48° | 57° | 0.81" | — |
| 1975 | 76° | 35° | 55° | — | — |
| 1974 | 76° | 39° | 57° | — | — |
| 1973 | 71° | 40° | 55° | — | — |
| 1972 | 64° | 42° | 53° | — | — |
| 1971 | 72° | 36° | 54° | — | — |
55 years of data from LONGMONT 2 ESE