Weather on May 18
Boise, ID
55 Years of Data
Avg High
71°F
Avg Low
47°F
Warmest
2006
77°F avg
Coldest
2003
44°F avg
About This Date
May 18th in Boise, ID typically brings pleasant spring weather, with average highs around 71°F and lows near 47°F. Over 55 years of records, the warmest May 18th was in 2006 (77°F average), while the coldest was 2003 (44°F) — a 33°F range across recorded history. Rain or other precipitation has occurred on about 29% of May 18th dates historically, with the wettest May 18th recording 0.69" of rain. The last decade has been 2.8°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.8°F warmer on this date compared to 20-30 years ago.
Planning for May 18th in Boise, ID? Great weather for outdoor activities.
Warming Trend
1.0°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 61° | 43° | 52° | 0.05" | — |
| 2024 | 76° | 41° | 58° | — | — |
| 2023 | 84° | 57° | 71° | — | — |
| 2022 | 76° | 46° | 61° | — | — |
| 2021 | 73° | 54° | 63° | — | — |
| 2020 | 60° | 51° | 56° | 0.38" | — |
| 2019 | 67° | 46° | 56° | — | — |
| 2018 | 75° | 54° | 64° | — | — |
| 2017 | 64° | 39° | 52° | — | — |
| 2016 | 82° | 52° | 67° | — | — |
| 2015 | 71° | 51° | 61° | — | — |
| 2014 | 69° | 50° | 60° | 0.1" | — |
| 2013 | 69° | 45° | 57° | — | — |
| 2012 | 69° | 45° | 57° | — | — |
| 2011 | 58° | 47° | 52° | 0.28" | — |
| 2010 | 62° | 52° | 57° | 0.64" | — |
| 2009 | 95° | 59° | 77° | — | — |
| 2008 | 92° | 61° | 76° | — | — |
| 2007 | 87° | 53° | 70° | — | — |
| 2006warmest | 92° | 62° | 77° | 0.03" | — |
| 2005 | 70° | 51° | 60° | 0.15" | — |
| 2004 | 61° | 50° | 55° | 0.69" | — |
| 2003coldest | 56° | 33° | 44° | — | — |
| 2002 | 87° | 52° | 69° | — | — |
| 2001 | 70° | 48° | 59° | — | — |
| 2000 | 73° | 45° | 59° | — | — |
| 1999 | 75° | 45° | 60° | — | — |
| 1998 | 63° | 37° | 50° | — | — |
| 1997 | 75° | 49° | 62° | — | — |
| 1996 | 62° | 47° | 54° | 0.64" | — |
| 1995 | 69° | 43° | 56° | — | — |
| 1994 | 64° | 34° | 49° | 0.23" | — |
| 1993 | 86° | 57° | 72° | — | — |
| 1992 | 88° | 57° | 72° | — | — |
| 1991 | 53° | 37° | 45° | 0.2" | — |
| 1990 | 68° | 44° | 56° | — | — |
| 1989 | 61° | 34° | 47° | 0.43" | — |
| 1988 | 66° | 38° | 52° | — | — |
| 1987 | 73° | 52° | 62° | — | — |
| 1986 | 85° | 57° | 71° | — | — |
| 1985 | 81° | 48° | 64° | — | — |
| 1984 | 73° | 41° | 57° | — | — |
| 1983 | 64° | 49° | 56° | — | — |
| 1982 | 59° | 43° | 51° | 0.03" | — |
| 1981 | 65° | 52° | 58° | 0.08" | — |
| 1980 | 77° | 48° | 63° | — | — |
| 1979 | 73° | 40° | 56° | — | — |
| 1978 | 65° | 48° | 56° | 0.03" | — |
| 1977 | 57° | 43° | 50° | 0.03" | — |
| 1976 | 75° | 41° | 58° | — | — |
| 1975 | 78° | 48° | 63° | — | — |
| 1974 | 57° | 36° | 46° | — | — |
| 1973 | 87° | 57° | 72° | — | — |
| 1972 | 68° | 41° | 55° | — | — |
| 1971 | 64° | 30° | 47° | — | — |
55 years of data from BOISE AIR TERMINAL