Weather on August 18
Longmont, CO
55 Years of Data
Avg High
87°F
Avg Low
55°F
Warmest
2024
79°F avg
Coldest
1992
62°F avg
About This Date
August 18th in Longmont, CO typically brings warm summer weather, with average highs around 87°F and lows near 55°F — a 32°F daily swing. Over 55 years of records, the warmest August 18th was in 2024 (79°F average), while the coldest was 1992 (62°F) — a 17°F range across recorded history. Rain or other precipitation has occurred on about 31% of August 18th dates historically, with the wettest August 18th recording 0.66" of rain. The last decade has been 5.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 5.0°F warmer on this date compared to 20-30 years ago.
Planning for August 18th in Longmont, CO? Stay hydrated and seek shade during peak afternoon hours. Consider bringing rain gear or an umbrella.
Warming Trend
0.6°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 90° | 58° | 74° | 0.25" | — |
| 2024warmest | 98° | 60° | 79° | — | — |
| 2023 | 93° | 61° | 77° | — | — |
| 2022 | 87° | 55° | 71° | — | — |
| 2021 | 96° | 58° | 77° | — | — |
| 2020 | 93° | 60° | 77° | — | — |
| 2019 | 88° | 59° | 73° | — | — |
| 2018 | 89° | 56° | 72° | — | — |
| 2017 | 87° | 51° | 69° | — | — |
| 2016 | 86° | 65° | 75° | 0.03" | — |
| 2015 | 75° | 52° | 63° | — | — |
| 2014 | 88° | 57° | 72° | — | — |
| 2013 | 91° | 56° | 73° | — | — |
| 2012 | 81° | 54° | 67° | — | — |
| 2011 | 97° | 60° | 78° | — | — |
| 2010 | 95° | 60° | 78° | — | — |
| 2009 | 76° | 49° | 62° | — | — |
| 2008 | 77° | 49° | 63° | — | — |
| 2007 | 88° | 59° | 73° | — | — |
| 2006 | 84° | 61° | 72° | 0.2" | — |
| 2005 | 86° | 56° | 71° | 0.08" | — |
| 2004 | 88° | 56° | 72° | — | — |
| 2003 | 91° | 58° | 74° | 0.13" | — |
| 2002 | 81° | 44° | 62° | — | — |
| 2001 | 87° | 44° | 66° | — | — |
| 2000 | 79° | 53° | 66° | 0.66" | — |
| 1999 | 92° | 46° | 69° | 0.36" | — |
| 1998 | 97° | 54° | 75° | — | — |
| 1997 | 80° | 53° | 67° | 0.23" | — |
| 1996 | 91° | 54° | 72° | — | — |
| 1995 | 96° | 59° | 78° | — | — |
| 1994 | 92° | 59° | 75° | — | — |
| 1993 | 91° | 54° | 72° | 0.41" | — |
| 1992coldest | 75° | 48° | 62° | 0.41" | — |
| 1991 | 85° | 55° | 70° | — | — |
| 1990 | 87° | 46° | 67° | — | — |
| 1989 | 87° | 54° | 70° | — | — |
| 1988 | 78° | 52° | 65° | 0.1" | — |
| 1987 | 95° | 51° | 73° | — | — |
| 1986 | 90° | 57° | 73° | — | — |
| 1985 | 77° | 53° | 65° | 0.03" | — |
| 1984 | 90° | 58° | 74° | — | — |
| 1983 | 95° | 58° | 76° | 0.03" | — |
| 1982 | 90° | 60° | 75° | — | — |
| 1981 | 82° | 53° | 68° | — | — |
| 1980 | 91° | 50° | 71° | — | — |
| 1979 | 79° | 55° | 67° | — | — |
| 1978 | 82° | 56° | 69° | — | — |
| 1977 | 73° | 59° | 66° | 0.15" | — |
| 1976 | 91° | 56° | 73° | 0.05" | — |
| 1975 | 86° | 50° | 68° | — | — |
| 1974 | 92° | 51° | 71° | 0.08" | — |
| 1973 | 90° | 56° | 73° | 0.28" | — |
| 1972 | 85° | 53° | 69° | — | — |
| 1971 | 92° | 53° | 72° | — | — |
55 years of data from LONGMONT 2 ESE