Weather on May 18
Longmont, CO
55 Years of Data
About This Date
May 18th in Longmont, CO typically brings pleasant spring weather, with average highs around 73°F and lows near 44°F — a 29°F daily swing. Over 55 years of records, the warmest May 18th was in 1988 (70°F average), while the coldest was 1983 (34°F) — a 36°F range across recorded history. Precipitation has occurred on 38% of recorded May 18th dates, with snow falling 4% of the time (heaviest snowfall: 5.3"). Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for May 18th in Longmont, CO? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 69° | 42° | 56° | 1.47" | — |
| 2025 | 70° | 47° | 58° | — | — |
| 2024 | 85° | 50° | 67° | — | — |
| 2023 | 82° | 48° | 65° | 1.14" | — |
| 2022 | 82° | 45° | 63° | 0.08" | — |
| 2021 | 66° | 47° | 56° | 2.21" | — |
| 2020 | 75° | 47° | 61° | — | — |
| 2019 | 72° | 37° | 54° | 0.51" | — |
| 2018 | 85° | 54° | 69° | — | — |
| 2017 | 60° | 31° | 45° | 7.9" | 5.3" |
| 2016 | 65° | 40° | 52° | — | — |
| 2015 | 58° | 41° | 49° | 0.38" | — |
| 2014 | 82° | 40° | 61° | — | — |
| 2013 | 80° | 61° | 70° | — | — |
| 2012 | 80° | 47° | 63° | — | — |
| 2011 | 58° | 42° | 50° | 1.8" | — |
| 2010 | 74° | 51° | 62° | — | — |
| 2008 | 82° | 47° | 64° | — | — |
| 2007 | 80° | 46° | 63° | — | — |
| 2006 | 85° | 52° | 68° | — | — |
| 2005 | 74° | 54° | 64° | — | — |
| 2004 | 71° | 54° | 62° | — | — |
| 2003 | 88° | 50° | 69° | — | — |
| 2002 | 61° | 42° | 51° | — | — |
| 2001 | 62° | 39° | 51° | 0.53" | — |
| 2000 | 64° | 40° | 52° | 2.01" | — |
| 1999 | 63° | 32° | 47° | — | — |
| 1998 | 87° | 42° | 65° | — | — |
| 1997 | 88° | 43° | 65° | — | — |
| 1996 | 85° | 52° | 68° | — | — |
| 1995 | 48° | 34° | 41° | 3.3" | — |
| 1994 | 88° | 46° | 67° | — | — |
| 1993 | 63° | 43° | 53° | 0.74" | — |
| 1992 | 83° | 44° | 63° | 0.13" | — |
| 1991 | 68° | 48° | 58° | 0.13" | — |
| 1990 | 88° | 32° | 60° | — | — |
| 1989 | 72° | 44° | 58° | — | — |
| 1988warmest | 88° | 53° | 70° | — | — |
| 1987 | 75° | 45° | 60° | 0.1" | — |
| 1986 | 71° | 40° | 55° | — | — |
| 1985 | 72° | 41° | 56° | 0.3" | — |
| 1984 | 72° | 44° | 58° | — | — |
| 1983coldest | 37° | 31° | 34° | 4.6" | 2" |
| 1982 | 71° | 41° | 56° | — | — |
| 1981 | 51° | 41° | 46° | 0.53" | — |
| 1980 | 46° | 39° | 43° | 0.89" | — |
| 1979 | 82° | 47° | 64° | — | — |
| 1978 | 70° | 38° | 54° | 3.94" | — |
| 1977 | 82° | 43° | 62° | — | — |
| 1976 | 76° | 42° | 59° | — | — |
| 1975 | 80° | 46° | 63° | — | — |
| 1974 | 70° | 52° | 61° | — | — |
| 1973 | 82° | 45° | 63° | — | — |
| 1972 | 84° | 44° | 64° | — | — |
| 1971 | 53° | 36° | 44° | 0.28" | — |
Longmont, CO Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Longmont, CO Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Longmont, CO Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Longmont, CO
Longmont, CO has no months that meet our "pleasant" threshold — every season has tradeoffs.