Weather on September 4
Longmont, CO
55 Years of Data
Avg High
86°F
Avg Low
51°F
Warmest
2013
79°F avg
Coldest
1974
55°F avg
About This Date
September 4th in Longmont, CO typically brings warm fall weather, with average highs around 86°F and lows near 51°F — a 35°F daily swing. Over 55 years of records, the warmest September 4th was in 2013 (79°F average), while the coldest was 1974 (55°F) — a 24°F range across recorded history. Rain or other precipitation has occurred on about 16% of September 4th dates historically, with the wettest September 4th recording 0.69" of rain. The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
Planning for September 4th in Longmont, CO? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
0.9°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 87° | 51° | 69° | — | — |
| 2024 | 94° | 56° | 75° | — | — |
| 2023 | 89° | 56° | 72° | 0.18" | — |
| 2022 | 92° | 57° | 74° | — | — |
| 2021 | 78° | 53° | 66° | 0.08" | — |
| 2020 | 85° | 51° | 68° | — | — |
| 2019 | 83° | 60° | 71° | — | — |
| 2018 | 84° | 52° | 68° | — | — |
| 2017 | 97° | 55° | 76° | — | — |
| 2016 | 86° | 50° | 68° | 0.1" | — |
| 2015 | 86° | 51° | 69° | — | — |
| 2014 | 88° | 55° | 71° | — | — |
| 2013warmest | 93° | 65° | 79° | — | — |
| 2012 | 91° | 57° | 74° | — | — |
| 2011 | 76° | 42° | 59° | — | — |
| 2010 | 94° | 50° | 72° | — | — |
| 2009 | 86° | 49° | 67° | — | — |
| 2008 | 73° | 44° | 59° | — | — |
| 2007 | 88° | 57° | 72° | 0.03" | — |
| 2006 | 72° | 42° | 57° | — | — |
| 2005 | 89° | 57° | 73° | — | — |
| 2004 | 86° | 57° | 72° | — | — |
| 2003 | 80° | 51° | 66° | — | — |
| 2002 | 88° | 48° | 68° | — | — |
| 2001 | 95° | 45° | 70° | — | — |
| 2000 | 90° | 55° | 72° | — | — |
| 1999 | 73° | 45° | 59° | 0.03" | — |
| 1998 | 96° | 47° | 71° | — | — |
| 1997 | 83° | 57° | 70° | — | — |
| 1996 | 92° | 45° | 68° | — | — |
| 1995 | 100° | 53° | 77° | — | — |
| 1994 | 89° | 49° | 69° | — | — |
| 1993 | 86° | 38° | 62° | — | — |
| 1992 | 87° | — | — | — | — |
| 1991 | 80° | 52° | 66° | — | — |
| 1990 | 91° | 54° | 72° | — | — |
| 1989 | 87° | 48° | 68° | — | — |
| 1988 | 85° | 42° | 63° | — | — |
| 1987 | 92° | — | — | — | — |
| 1986 | 83° | 47° | 65° | — | — |
| 1985 | 82° | 58° | 70° | 0.18" | — |
| 1984 | 96° | 46° | 71° | — | — |
| 1983 | 94° | 59° | 76° | 0.46" | — |
| 1982 | 88° | 53° | 70° | — | — |
| 1981 | 74° | 51° | 62° | — | — |
| 1980 | 92° | 49° | 70° | — | — |
| 1979 | 93° | 50° | 72° | — | — |
| 1978 | 94° | 51° | 72° | — | — |
| 1977 | 89° | 55° | 72° | 0.03" | — |
| 1976 | 84° | 52° | 68° | — | — |
| 1975 | 82° | 51° | 67° | — | — |
| 1974coldest | 71° | 40° | 55° | — | — |
| 1973 | 81° | 44° | 62° | — | — |
| 1972 | 72° | 45° | 58° | — | — |
| 1971 | 88° | 45° | 66° | 0.69" | — |
55 years of data from LONGMONT 2 ESE