Weather on May 31
Boise, ID
55 Years of Data
Avg High
77°F
Avg Low
50°F
Warmest
2025
81°F avg
Coldest
1990
46°F avg
About This Date
May 31st in Boise, ID typically brings pleasant spring weather, with average highs around 77°F and lows near 50°F — a 27°F daily swing. Over 55 years of records, the warmest May 31st was in 2025 (81°F average), while the coldest was 1990 (46°F) — a 35°F range across recorded history. Rain or other precipitation has occurred on about 18% of May 31st dates historically, with the wettest May 31st recording 1.45" 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 May 31st in Boise, ID? Great weather for outdoor activities.
Warming Trend
1.3°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025warmest | 100° | 62° | 81° | — | — |
| 2024 | 76° | 45° | 60° | — | — |
| 2023 | 76° | 58° | 67° | 0.13" | — |
| 2022 | 66° | 45° | 55° | — | — |
| 2021 | 87° | 53° | 70° | — | — |
| 2020 | 78° | 58° | 68° | 0.23" | — |
| 2019 | 80° | 55° | 68° | — | — |
| 2018 | 69° | 53° | 61° | — | — |
| 2017 | 88° | 60° | 74° | — | — |
| 2016 | 81° | 47° | 64° | — | — |
| 2015 | 94° | 57° | 75° | — | — |
| 2014 | 82° | 48° | 65° | — | — |
| 2013 | 70° | 44° | 57° | — | — |
| 2012 | 84° | 52° | 68° | — | — |
| 2011 | 74° | 54° | 64° | — | — |
| 2010 | 66° | 55° | 61° | 0.03" | — |
| 2009 | 88° | 64° | 76° | — | — |
| 2008 | 78° | 51° | 65° | 0.03" | — |
| 2007 | 88° | 53° | 70° | — | — |
| 2006 | 82° | 52° | 67° | — | — |
| 2005 | 73° | 51° | 62° | 1.45" | — |
| 2004 | 72° | 45° | 58° | — | — |
| 2003 | 78° | 53° | 66° | — | — |
| 2002 | 88° | 55° | 71° | — | — |
| 2001 | 85° | 51° | 68° | — | — |
| 2000 | 64° | 37° | 51° | — | — |
| 1999 | 77° | 44° | 61° | — | — |
| 1998 | 69° | 43° | 56° | — | — |
| 1997 | 87° | 62° | 75° | — | — |
| 1996 | 72° | 42° | 57° | — | — |
| 1995 | 86° | 52° | 69° | — | — |
| 1994 | 70° | 53° | 61° | — | — |
| 1993 | 75° | 52° | 63° | 0.38" | — |
| 1992 | 85° | 48° | 66° | — | — |
| 1991 | 75° | 46° | 61° | — | — |
| 1990coldest | 53° | 39° | 46° | 0.76" | — |
| 1989 | 78° | 38° | 58° | — | — |
| 1988 | 68° | 38° | 53° | — | — |
| 1987 | 66° | 47° | 56° | 0.18" | — |
| 1986 | 97° | 62° | 79° | — | — |
| 1985 | 76° | 48° | 62° | — | — |
| 1984 | 60° | 40° | 50° | — | — |
| 1983 | 73° | 59° | 66° | — | — |
| 1982 | 79° | 47° | 63° | — | — |
| 1981 | 71° | 46° | 59° | — | — |
| 1980 | 72° | 47° | 59° | — | — |
| 1979 | 74° | 37° | 55° | — | — |
| 1978 | 70° | 32° | 51° | — | — |
| 1977 | 93° | 57° | 75° | — | — |
| 1976 | 70° | 48° | 59° | 0.43" | — |
| 1975 | 83° | 49° | 66° | — | — |
| 1974 | 75° | 42° | 59° | — | — |
| 1973 | 74° | 54° | 64° | — | — |
| 1972 | 93° | 63° | 78° | — | — |
| 1971 | 67° | 49° | 58° | 0.05" | — |
55 years of data from BOISE AIR TERMINAL