Weather on March 21
Boise, ID
55 Years of Data
Avg High
57°F
Avg Low
36°F
Warmest
2026
58°F avg
Coldest
1982
35°F avg
About This Date
March 21st in Boise, ID typically brings cool spring weather, with average highs around 57°F and lows near 36°F. Over 56 years of records, the warmest March 21st was in 2026 (58°F average), while the coldest was 1982 (35°F) — a 23°F range across recorded history. Precipitation has occurred on 30% of recorded March 21st dates, with snow falling 5% of the time (heaviest snowfall: 2"). 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 March 21st in Boise, ID? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Warming Trend
1.0°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026warmest | 69° | 46° | 58° | — | — |
| 2025 | 55° | 35° | 45° | 0.08" | — |
| 2024 | 63° | 47° | 55° | — | — |
| 2023 | 51° | 33° | 42° | 0.25" | 0.2" |
| 2022 | 53° | 33° | 43° | — | — |
| 2021 | 51° | 31° | 41° | — | — |
| 2020 | 59° | 36° | 47° | — | — |
| 2019 | 62° | 36° | 49° | — | — |
| 2018 | 62° | 42° | 52° | 0.38" | — |
| 2017 | 62° | 45° | 53° | 0.25" | — |
| 2016 | 60° | 41° | 51° | 0.91" | — |
| 2015 | 65° | 45° | 55° | — | — |
| 2014 | 49° | 24° | 37° | — | — |
| 2013 | 45° | 33° | 39° | — | — |
| 2012 | 66° | 44° | 55° | — | — |
| 2011 | 56° | 39° | 47° | 1.09" | — |
| 2010 | 62° | 38° | 50° | 0.18" | — |
| 2009 | 65° | 43° | 54° | 0.64" | — |
| 2008 | 47° | 31° | 39° | — | — |
| 2007 | 51° | 31° | 41° | — | — |
| 2006 | 52° | 35° | 43° | — | — |
| 2005 | 52° | 40° | 46° | — | — |
| 2004 | 71° | 41° | 56° | — | — |
| 2003 | 56° | 37° | 46° | — | — |
| 2002 | 69° | 35° | 52° | — | — |
| 2001 | 65° | 41° | 53° | — | — |
| 2000 | 54° | 25° | 39° | — | — |
| 1999 | 55° | 39° | 47° | 0.53" | — |
| 1998 | 64° | 40° | 52° | — | — |
| 1997 | 58° | 32° | 45° | — | — |
| 1996 | 63° | 38° | 50° | — | — |
| 1995 | 53° | 35° | 44° | 0.03" | — |
| 1994 | 57° | 39° | 48° | — | — |
| 1993 | 60° | 34° | 47° | — | — |
| 1992 | 62° | 28° | 45° | — | — |
| 1991 | 57° | 27° | 42° | — | — |
| 1990 | 63° | 32° | 47° | — | — |
| 1989 | 45° | 40° | 42° | 0.61" | — |
| 1988 | 54° | 36° | 45° | 0.61" | — |
| 1987 | 52° | 30° | 41° | — | — |
| 1986 | 67° | 41° | 54° | — | — |
| 1985 | 48° | 33° | 41° | 0.23" | — |
| 1984 | 55° | 37° | 46° | 0.23" | — |
| 1983 | 53° | 32° | 43° | — | — |
| 1982coldest | 47° | 24° | 35° | — | — |
| 1981 | 57° | 40° | 48° | 0.13" | — |
| 1980 | 45° | 32° | 38° | 0.71" | 2" |
| 1979 | 58° | 36° | 47° | — | — |
| 1978 | 68° | 39° | 54° | — | — |
| 1977 | 56° | 25° | 40° | — | — |
| 1976 | 56° | 27° | 41° | — | — |
| 1975 | 42° | 33° | 38° | 0.3" | 0.2" |
| 1974 | 53° | 26° | 40° | — | — |
| 1973 | 49° | 40° | 44° | — | — |
| 1972 | 64° | 41° | 53° | — | — |
| 1971 | 58° | 36° | 47° | — | — |
56 years of data from BOISE AIR TERMINAL