Weather on September 1
Boise, ID
55 Years of Data
Avg High
86°F
Avg Low
55°F
Warmest
1998
82°F avg
Coldest
1975
56°F avg
About This Date
September 1st in Boise, ID typically brings warm fall weather, with average highs around 86°F and lows near 55°F — a 31°F daily swing. Over 55 years of records, the warmest September 1st was in 1998 (82°F average), while the coldest was 1975 (56°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 4% of September 1st dates historically. The last decade has been 2.3°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.3°F warmer on this date compared to 20-30 years ago.
Planning for September 1st in Boise, ID? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 101° | 64° | 82° | — | — |
| 2024 | 99° | 61° | 80° | — | — |
| 2023 | 85° | 62° | 73° | — | — |
| 2022 | 97° | 64° | 80° | — | — |
| 2021 | 80° | 47° | 63° | — | — |
| 2020 | 84° | 49° | 66° | — | — |
| 2019 | 97° | 65° | 81° | — | — |
| 2018 | 82° | 52° | 67° | — | — |
| 2017 | 93° | 56° | 74° | — | — |
| 2016 | 86° | 58° | 72° | — | — |
| 2015 | 87° | 58° | 72° | — | — |
| 2014 | 77° | 49° | 63° | — | — |
| 2013 | 94° | 62° | 78° | — | — |
| 2012 | 85° | 57° | 71° | — | — |
| 2011 | 77° | 48° | 63° | — | — |
| 2010 | 78° | 60° | 69° | — | — |
| 2009 | 95° | 66° | 81° | — | — |
| 2008 | 70° | 48° | 59° | — | — |
| 2007 | 96° | 62° | 79° | — | — |
| 2006 | 84° | 46° | 65° | — | — |
| 2005 | 87° | 54° | 70° | — | — |
| 2004 | 90° | 64° | 77° | — | — |
| 2003 | 88° | 63° | 75° | — | — |
| 2002 | 87° | 57° | 72° | — | — |
| 2001 | 92° | 59° | 75° | — | — |
| 2000 | 71° | 54° | 62° | 0.25" | — |
| 1999 | 73° | 42° | 58° | — | — |
| 1998warmest | 98° | 66° | 82° | — | — |
| 1997 | 97° | 65° | 81° | — | — |
| 1996 | 77° | 49° | 63° | — | — |
| 1995 | 94° | 56° | 75° | — | — |
| 1994 | 87° | 55° | 71° | — | — |
| 1993 | 85° | 53° | 69° | — | — |
| 1992 | 85° | 59° | 72° | — | — |
| 1991 | 87° | 60° | 74° | — | — |
| 1990 | 91° | 50° | 71° | — | — |
| 1989 | 89° | 56° | 72° | — | — |
| 1988 | 90° | 50° | 70° | — | — |
| 1987 | 101° | 62° | 81° | — | — |
| 1986 | 77° | 47° | 62° | — | — |
| 1985 | 76° | 53° | 64° | — | — |
| 1984 | 73° | 47° | 60° | — | — |
| 1983 | 79° | 55° | 67° | 0.08" | — |
| 1982 | 86° | 50° | 68° | — | — |
| 1981 | 85° | 55° | 70° | — | — |
| 1980 | 79° | 45° | 62° | — | — |
| 1979 | 90° | 56° | 73° | — | — |
| 1978 | 88° | 55° | 71° | — | — |
| 1977 | 77° | 41° | 59° | — | — |
| 1976 | 100° | 61° | 80° | — | — |
| 1975coldest | 70° | 43° | 56° | — | — |
| 1974 | 89° | 52° | 70° | — | — |
| 1973 | 71° | 45° | 58° | — | — |
| 1972 | 84° | 50° | 67° | — | — |
| 1971 | 85° | 46° | 65° | — | — |
55 years of data from BOISE AIR TERMINAL