Weather on August 31
Boise, ID
55 Years of Data
Avg High
84°F
Avg Low
55°F
Warmest
2022
87°F avg
Coldest
1999
54°F avg
About This Date
August 31st in Boise, ID typically brings warm summer weather, with average highs around 84°F and lows near 55°F — a 29°F daily swing. Over 55 years of records, the warmest August 31st was in 2022 (87°F average), while the coldest was 1999 (54°F) — a 33°F range across recorded history. Rain or other precipitation has occurred on about 9% of August 31st dates historically. The last decade has been 3.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.4°F warmer on this date compared to 20-30 years ago.
Planning for August 31st in Boise, ID? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.9°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 97° | 67° | 82° | — | — |
| 2024 | 91° | 59° | 75° | — | — |
| 2023 | 90° | 56° | 73° | — | — |
| 2022warmest | 106° | 69° | 87° | — | — |
| 2021 | 81° | 54° | 67° | — | — |
| 2020 | 76° | 54° | 65° | — | — |
| 2019 | 96° | 65° | 80° | — | — |
| 2018 | 80° | 58° | 69° | — | — |
| 2017 | 89° | 65° | 77° | — | — |
| 2016 | 92° | 62° | 77° | — | — |
| 2015 | 83° | 52° | 67° | — | — |
| 2014 | 74° | 48° | 61° | — | — |
| 2013 | 95° | 59° | 77° | — | — |
| 2012 | 88° | 63° | 75° | — | — |
| 2011 | 80° | 58° | 69° | — | — |
| 2010 | 72° | 50° | 61° | — | — |
| 2009 | 88° | 62° | 75° | — | — |
| 2008 | 69° | 52° | 60° | — | — |
| 2007 | 94° | 68° | 81° | 0.1" | — |
| 2006 | 74° | 43° | 58° | — | — |
| 2005 | 80° | 50° | 65° | — | — |
| 2004 | 102° | 68° | 85° | — | — |
| 2003 | 89° | 60° | 75° | — | — |
| 2002 | 87° | 61° | 74° | — | — |
| 2001 | 91° | 64° | 78° | — | — |
| 2000 | 80° | 57° | 69° | 0.23" | — |
| 1999coldest | 66° | 43° | 54° | — | — |
| 1998 | 92° | 58° | 75° | — | — |
| 1997 | 86° | 63° | 74° | — | — |
| 1996 | 82° | 56° | 69° | — | — |
| 1995 | 96° | 54° | 75° | — | — |
| 1994 | 87° | 52° | 69° | — | — |
| 1993 | 85° | 47° | 66° | — | — |
| 1992 | 86° | 61° | 73° | — | — |
| 1991 | 96° | 63° | 79° | — | — |
| 1990 | 84° | 48° | 66° | — | — |
| 1989 | 80° | 44° | 62° | — | — |
| 1988 | 87° | 48° | 68° | — | — |
| 1987 | 94° | 57° | 75° | — | — |
| 1986 | 78° | 47° | 62° | — | — |
| 1985 | 78° | 48° | 63° | — | — |
| 1984 | 61° | 55° | 58° | — | — |
| 1983 | 93° | 61° | 77° | 0.25" | — |
| 1982 | 81° | 46° | 63° | — | — |
| 1981 | 79° | 43° | 61° | — | — |
| 1980 | 73° | 43° | 58° | — | — |
| 1979 | 77° | 56° | 66° | 0.05" | — |
| 1978 | 83° | 58° | 70° | — | — |
| 1977 | 73° | 42° | 58° | — | — |
| 1976 | 92° | 55° | 73° | — | — |
| 1975 | 73° | 48° | 61° | — | — |
| 1974 | 91° | 56° | 73° | — | — |
| 1973 | 69° | 53° | 61° | 0.05" | — |
| 1972 | 83° | 50° | 66° | — | — |
| 1971 | 75° | 60° | 68° | — | — |
55 years of data from BOISE AIR TERMINAL