Boise weather by month

Frost and snow-likely months in Boise

Nights in Boise average 36°F (2°C) or below in 5 months (January, February, March, November and December). January, February and December combine average lows at or below 32°F (0°C) with 0.4 in (10 mm) or more of monthly precipitation, so precipitation then is likely to fall as snow. The coldest month is January with an average low of 23°F (-5°C) and a record low of -4°F (-20°C).

• January: average low 23°F (-5°C), record low -4°F (-20°C), 0.9 in (22 mm) of precipitation — snow-likely
• February: average low 30°F (-1°C), record low 12°F (-11°C), 1.1 in (27 mm) of precipitation — snow-likely
• March: average low 35°F (1°C), record low 19°F (-7°C), 1.2 in (30 mm) of precipitation
• November: average low 34°F (1°C), record low 6°F (-14°C), 1.1 in (29 mm) of precipitation
• December: average low 26°F (-3°C), record low 11°F (-12°C), 1.5 in (37 mm) of precipitation — snow-likely

These records carry temperature and precipitation, not snowfall totals.

Best time to visit Boise

The most comfortable time to visit Boise is generally May to June and September, balancing mild daytime temperatures against the driest stretch of the year. The city has strongly marked seasons and rain concentrates around May, totalling about 10.9 in (277 mm) a year.

Travellers who prefer heat should aim for July, when highs average 94°F (35°C). May is the month to avoid if rain would spoil your plans — it averages 1.8 in (45 mm), roughly 45× the rainfall of the driest month (July).