Climateby Month

Seattle vs Boise weather

Seattle, WA and Boise, ID · 405 mi apart

July highs: 77°F in Seattle, 93°F in Boise (Boise is 16°F warmer). January highs: 47°F and 39°F (Seattle is 8°F warmer). Seattle has about 163 wet days a year, Boise about 89. Snow: 3.8 in a year in Seattle, 17.6 in in Boise.

Seattle, WA

20°40°60°80°100° January: normal high 47°F (8°C), low 37°F (3°C) 47° 37° February: normal high 50°F (10°C), low 37°F (3°C) March: normal high 54°F (12°C), low 39°F (4°C) April: normal high 59°F (15°C), low 43°F (6°C) May: normal high 65°F (18°C), low 48°F (9°C) June: normal high 70°F (21°C), low 53°F (12°C) July: normal high 77°F (25°C), low 57°F (14°C) 77° 57° August: normal high 77°F (25°C), low 57°F (14°C) September: normal high 71°F (22°C), low 53°F (12°C) October: normal high 61°F (16°C), low 47°F (8°C) November: normal high 52°F (11°C), low 41°F (5°C) December: normal high 47°F (8°C), low 37°F (3°C) JFMAMJJASOND

Best months: June, July, August

Boise, ID

20°40°60°80°100° January: normal high 39°F (4°C), low 26°F (-3°C) 39° 26° February: normal high 46°F (8°C), low 29°F (-2°C) March: normal high 56°F (13°C), low 35°F (2°C) April: normal high 62°F (17°C), low 40°F (4°C) May: normal high 72°F (22°C), low 48°F (9°C) June: normal high 81°F (27°C), low 54°F (12°C) July: normal high 93°F (34°C), low 62°F (17°C) 93° 62° August: normal high 91°F (33°C), low 61°F (16°C) September: normal high 80°F (27°C), low 53°F (12°C) October: normal high 65°F (18°C), low 42°F (6°C) November: normal high 49°F (9°C), low 32°F (0°C) December: normal high 39°F (4°C), low 25°F (-4°C) JFMAMJJASOND

Best months: May

Which city for what

  • Milder winters: Seattle (January high 47°F vs January high 39°F)
  • Cooler summers: Seattle (July high 77°F vs July high 93°F)
  • Fewer wet days: Boise (89 a year vs 163 a year)
  • Less snow: Seattle (3.8 in vs 17.6 in)
  • Longer growing season: Seattle (259 frost-free days vs 179 frost-free days)
  • More comfortable days: Seattle (117 a year vs 75 a year)

Listed only where the difference is at least 3°F in highs, 10 days a year or 3 in of snow.

Season by season

SeasonAvg high SeattleAvg high BoiseWet days SeattleWet days Boise
Winter (Dec-Feb)48°F41°F5332
Spring (Mar-May)59°F63°F4628
Summer (Jun-Aug)75°F88°F2210
Fall (Sep-Nov)61°F65°F4220

Side by side over a year

SeattleBoise
Hot days (90°F+)255
Freezing nights25108
Muggy days00
Comfortable days11775
Precipitation37.8 in11.5 in
Snowfall3.8 in17.6 in
Frost dateslast Mar 8, first Nov 23last Apr 24, first Oct 21
Daylight in June / December15.9 h / 8.5 h15.4 h / 9.0 h
Best monthsJune, July, AugustMay

Day counts from each city's daily records, 1991-2020. Comfortable days: highs 65-80°F and dew point under 60°F.

Month by month

MonthHigh SeattleHigh BoiseWet days SeattleWet days Boise
January47°F39°F1911
February50°F46°F169
March54°F56°F1810
April59°F62°F169
May65°F72°F128
June70°F81°F115
July77°F93°F52
August77°F91°F62
September71°F80°F94
October61°F65°F156
November52°F49°F1910
December47°F39°F1912

Both charts use the same temperature scale.

Where the numbers come from

  • Seattle, WA: temperature from Seattle Sand Pt WSFO (USW00094290), 6.6 mi NNE of the city center; precipitation from Seattle Sand Pt WSFO (USW00094290). NOAA 1991-2020 normals and daily records.
  • Boise, ID: temperature from Boise Air Terminal (USW00024131), 3.7 mi SSW of the city center; precipitation from Boise Air Terminal (USW00024131). NOAA 1991-2020 normals and daily records.

Every station for each city, including humidity and frost, is listed on the city page. Methodology.