Climateby Month

Seattle vs Portland weather

Seattle, WA and Portland, OR · 145 mi apart

July highs: 77°F in Seattle, 80°F in Portland (Portland is 3°F warmer). January highs: 47°F and 47°F. Seattle has about 163 wet days a year, Portland about 156. Snow: 3.8 in a year in Seattle, 4.2 in in Portland.

Seattle, WA

30°40°50°60°70°80°90° 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

Portland, OR

30°40°50°60°70°80°90° January: normal high 47°F (8°C), low 37°F (3°C) February: normal high 51°F (11°C), low 39°F (4°C) March: normal high 56°F (13°C), low 41°F (5°C) April: normal high 61°F (16°C), low 44°F (7°C) May: normal high 68°F (20°C), low 49°F (9°C) June: normal high 73°F (23°C), low 53°F (12°C) July: normal high 80°F (27°C), low 58°F (14°C) August: normal high 81°F (27°C), low 59°F (15°C) 81° 59° September: normal high 75°F (24°C), low 55°F (13°C) October: normal high 63°F (17°C), low 48°F (9°C) November: normal high 52°F (11°C), low 42°F (6°C) December: normal high 46°F (8°C), low 37°F (3°C) 46° 37° JFMAMJJASOND

Best months: June

Which city for what

  • Cooler summers: Seattle (July high 77°F vs July high 80°F)
  • Longer growing season: Seattle (259 frost-free days vs 247 frost-free days)
  • More comfortable days: Seattle (117 a year vs 104 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 PortlandWet days SeattleWet days Portland
Winter (Dec-Feb)48°F48°F5353
Spring (Mar-May)59°F62°F4648
Summer (Jun-Aug)75°F78°F2216
Fall (Sep-Nov)61°F63°F4238

Side by side over a year

SeattlePortland
Hot days (90°F+)212
Freezing nights2518
Muggy days00
Comfortable days117104
Precipitation37.8 in36.9 in
Snowfall3.8 in4.2 in
Frost dateslast Mar 8, first Nov 23last Mar 13, first Nov 19
Daylight in June / December15.9 h / 8.5 h15.6 h / 8.8 h
Best monthsJune, July, AugustJune

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 PortlandWet days SeattleWet days Portland
January47°F47°F1919
February50°F51°F1616
March54°F56°F1818
April59°F61°F1617
May65°F68°F1213
June70°F73°F119
July77°F80°F54
August77°F81°F64
September71°F75°F97
October61°F63°F1514
November52°F52°F1918
December47°F46°F1919

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.
  • Portland, OR: temperature from Portland Kgw-Tv (USC00356749), 0.7 mi WSW of the city center; precipitation from Portland Intl Airport (USW00024229). NOAA 1991-2020 normals and daily records.

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