Boise's Climate
Averages and Records by Month
| | Jan | Feb | March | April | May | June |
| Average High | 36°F | 44°F | 52°F | 61°F | 71°F | 80°F |
| Average Low | 21°F | 27°F | 31°F | 36°F | 43°F | 52°F |
| Mean | 29°F | 36°F | 42°F | 49°F | 58°F | 67°F |
| Average Precipitation | 1.50 in | 1.10 in | 1.30 in | 1.20 in | 1.10 in | 0.80 in |
| Record High | 63°F
(1963) | 71°F
(1992) | 81°F
(1978) | 92°F
(1987 | 98°F
(1986) | 109°F
(1940) |
| Record Low | -17°F
(1950) | -15°F
(1989) | 6°F
(1968) | 19°F
(1968) | 22°F
(1982) | 31°F
(1995) |
| | | | | | | |
| | July | Aug | Sept | Oct | Nov | Dec |
| Average High | 90°F | 88°F | 77°F | 64°F | 48°F | 37°F |
| Average Low | 57°F | 56°F | 48°F | 39°F | 31°F | 22°F |
| Mean | 74°F | 73°F | 63°F | 52°F | 40°F | 30°F |
| Average Precipitation | 0.40 in | 0.40 in | 0.80 in | 0.80 in | 1.50 in | 1.40 in |
| Record High | 111°F
(1960) | 110°F
(1961) | 102°F
(1945) | 94°F
(1992) | 74°F
(1988) | 65°F
(1964) |
| Record Low | 35°F
(1986) | 34°F
(1992) | 23°F
(1970) | 11°F
(1971) | -3°F
(1985) | -25°F
(1990) |