Weather on September 19
Longmont, CO
55 Years of Data
Avg High
79°F
Avg Low
44°F
Warmest
1998
76°F avg
Coldest
1971
31°F avg
About This Date
September 19th in Longmont, CO typically brings pleasant fall weather, with average highs around 79°F and lows near 44°F — a 35°F daily swing. Over 55 years of records, the warmest September 19th was in 1998 (76°F average), while the coldest was 1971 (31°F) — a 45°F range across recorded history. Rain or other precipitation has occurred on about 9% of September 19th dates historically, with the wettest September 19th recording 4.06" of rain. The last decade has been 4.3°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.3°F warmer on this date compared to 20-30 years ago.
Planning for September 19th in Longmont, CO? Great weather for outdoor activities.
Warming Trend
1.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 72° | 46° | 59° | — | — |
| 2024 | 83° | 47° | 65° | — | — |
| 2023 | 84° | 47° | 65° | — | — |
| 2022 | 84° | 49° | 66° | — | — |
| 2021 | 88° | 45° | 66° | — | — |
| 2020 | 77° | 48° | 63° | — | — |
| 2019 | 79° | 48° | 63° | — | — |
| 2018 | 91° | 53° | 72° | — | — |
| 2017 | 83° | 48° | 65° | — | — |
| 2016 | 90° | 54° | 72° | — | — |
| 2015 | 77° | 40° | 58° | — | — |
| 2014 | 84° | 53° | 69° | — | — |
| 2013 | 72° | 54° | 63° | — | — |
| 2012 | 81° | 52° | 66° | — | — |
| 2011 | 80° | 43° | 61° | — | — |
| 2010 | 93° | 41° | 67° | — | — |
| 2009 | 79° | 43° | 61° | — | — |
| 2008 | 77° | 48° | 63° | — | — |
| 2007 | 79° | 43° | 61° | — | — |
| 2006 | 77° | 37° | 57° | — | — |
| 2005 | 80° | 46° | 63° | — | — |
| 2004 | 92° | 46° | 69° | — | — |
| 2003 | 60° | 35° | 48° | — | — |
| 2002 | 72° | 45° | 58° | — | — |
| 2001 | 73° | 38° | 55° | — | — |
| 2000 | 85° | 50° | 67° | — | — |
| 1999 | 85° | 42° | 63° | — | — |
| 1998warmest | 94° | 58° | 76° | — | — |
| 1997 | 84° | 50° | 67° | — | — |
| 1996 | 61° | 33° | 47° | 2.44" | — |
| 1995 | 72° | 47° | 59° | 0.81" | — |
| 1994 | 89° | 54° | 71° | — | — |
| 1993 | 57° | 38° | 47° | 0.94" | — |
| 1992 | 85° | — | — | — | — |
| 1991 | 58° | 34° | 46° | — | — |
| 1990 | 78° | 42° | 60° | 2.11" | — |
| 1989 | 88° | 46° | 67° | — | — |
| 1988 | 83° | 30° | 56° | — | — |
| 1987 | 70° | 35° | 52° | — | — |
| 1986 | 75° | 44° | 60° | — | — |
| 1985 | 80° | 50° | 65° | — | — |
| 1984 | 87° | 42° | 65° | — | — |
| 1983 | 82° | 47° | 64° | — | — |
| 1982 | 74° | 47° | 60° | — | — |
| 1981 | 88° | 40° | 64° | — | — |
| 1980 | 91° | 43° | 67° | — | — |
| 1979 | 79° | 42° | 60° | — | — |
| 1978 | 74° | 39° | 56° | — | — |
| 1977 | 74° | 41° | 57° | — | — |
| 1976 | 82° | 47° | 64° | 4.06" | — |
| 1975 | 63° | 43° | 53° | — | — |
| 1974 | 83° | 44° | 63° | — | — |
| 1973 | 81° | 41° | 61° | — | — |
| 1972 | 88° | 50° | 69° | — | — |
| 1971coldest | 43° | 20° | 31° | — | — |
55 years of data from LONGMONT 2 ESE