Weather on April 21
Longmont, CO
55 Years of Data
Avg High
62°F
Avg Low
34°F
Warmest
2019
65°F avg
Coldest
2021
27°F avg
About This Date
April 21st in Longmont, CO typically brings mild spring weather, with average highs around 62°F and lows near 34°F — a 28°F daily swing. Over 55 years of records, the warmest April 21st was in 2019 (65°F average), while the coldest was 2021 (27°F) — a 38°F range across recorded history. Precipitation has occurred on 24% of recorded April 21st dates, with snow falling 4% of the time (heaviest snowfall: 9"). 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 April 21st in Longmont, CO? Great weather for outdoor activities.
Warming Trend
0.6°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 66° | 36° | 51° | — | — |
| 2024 | 35° | 31° | 33° | 0.15" | — |
| 2023 | 53° | 28° | 41° | — | — |
| 2022 | 78° | 41° | 60° | — | — |
| 2021coldest | 38° | 16° | 27° | — | — |
| 2020 | 67° | 36° | 51° | — | — |
| 2019warmest | 83° | 47° | 65° | — | — |
| 2018 | 52° | 33° | 42° | 0.89" | 1.1" |
| 2017 | 53° | 39° | 46° | 0.91" | — |
| 2016 | 65° | 37° | 51° | — | — |
| 2015 | 67° | 33° | 50° | — | — |
| 2014 | 66° | 41° | 54° | — | — |
| 2013 | 63° | 33° | 48° | — | — |
| 2012 | 75° | 48° | 62° | — | — |
| 2011 | 70° | 37° | 53° | 0.51" | — |
| 2010 | 59° | 43° | 51° | 0.08" | — |
| 2009 | 75° | 42° | 59° | — | — |
| 2008 | 68° | 32° | 50° | — | — |
| 2007 | 65° | 43° | 54° | — | — |
| 2006 | 74° | 36° | 55° | — | — |
| 2005 | 60° | 31° | 45° | 0.25" | — |
| 2004 | 66° | 39° | 53° | — | — |
| 2003 | 64° | 38° | 51° | — | — |
| 2002 | 45° | 21° | 33° | 0.15" | — |
| 2001 | 61° | 35° | 48° | — | — |
| 2000 | 71° | 28° | 50° | — | — |
| 1999 | 69° | 37° | 53° | — | — |
| 1998 | 55° | 28° | 42° | 0.13" | — |
| 1997 | 75° | 41° | 58° | — | — |
| 1996 | 57° | 26° | 42° | — | — |
| 1995 | 53° | 32° | 43° | 0.64" | — |
| 1994 | 76° | 39° | 57° | — | — |
| 1993 | 52° | 28° | 40° | — | — |
| 1992 | 63° | 24° | 43° | — | — |
| 1991 | 56° | 40° | 48° | 0.05" | — |
| 1990 | 72° | 34° | 53° | — | — |
| 1989 | 84° | 32° | 58° | — | — |
| 1988 | 74° | 38° | 56° | — | — |
| 1987 | 44° | 27° | 35° | — | — |
| 1986 | 66° | 41° | 54° | — | — |
| 1985 | 62° | 38° | 50° | — | — |
| 1984 | 39° | 31° | 35° | 2.03" | 9" |
| 1983 | 72° | 40° | 56° | 0.03" | — |
| 1982 | 41° | 16° | 28° | — | — |
| 1981 | 62° | 39° | 51° | — | — |
| 1980 | 83° | 37° | 60° | — | — |
| 1979 | 63° | 34° | 48° | — | — |
| 1978 | 65° | 32° | 48° | — | — |
| 1977 | 52° | 31° | 41° | — | — |
| 1976 | 63° | 40° | 51° | — | — |
| 1975 | 64° | 34° | 49° | — | — |
| 1974 | 66° | 34° | 50° | — | — |
| 1973 | 54° | 30° | 42° | — | — |
| 1972 | 50° | 29° | 39° | — | — |
| 1971 | 53° | 37° | 45° | 0.03" | — |
55 years of data from LONGMONT 2 ESE