St. Helens, OR vs Seattle, WA

Side-by-side comparison of monthly climate normals (NOAA 1991-2020).

St. Helens is cooler than Seattle (51.6°F vs 53.8°F annual avg) and drier than it (0 in vs 36.5 in per year). St. Helens has a Desert (cold) climate; Seattle a Warm-summer Mediterranean climate.

St. Helens, OR

Annual avg
51.6°F
Annual precip
0 in
Warmest month
August (79.3°F)
Coldest month
January (32.9°F)
Annual swing
29.5°F
Pleasant months
4 / 12
Desert (cold) BWk USDA Zone 8b

Seattle, WA

Annual avg
53.8°F
Annual precip
36.5 in
Warmest month
August (77.4°F)
Coldest month
December (36.2°F)
Annual swing
25.8°F
Pleasant months
4 / 12
Warm-summer Mediterranean Csb USDA Zone 9a

Best months to visit each city

St. Helens

J
F
M
A
M
J
J
A
S
O
N
D

Seattle

J
F
M
A
M
J
J
A
S
O
N
D

Month-by-month comparison

Month St. Helens Seattle
High Low Precip High Low Precip
January 43.2°F 32.9°F — in 48.6°F 36.8°F 5.21 in
February 47.1°F 33.2°F — in 50.7°F 36.8°F 3.71 in
March 52.9°F 36.1°F — in 54.8°F 39.4°F 3.94 in
April 58.7°F 40.1°F — in 59.8°F 43.6°F 2.89 in
May 66.6°F 46.1°F — in 66.5°F 49.3°F 1.98 in
June 71.6°F 50.4°F — in 71.2°F 54.0°F 1.22 in
July 78.8°F 55.0°F — in 77.3°F 57.5°F 0.56 in
August 79.3°F 54.9°F — in 77.4°F 58.1°F 0.83 in
September 73.5°F 51.9°F — in 71.7°F 53.9°F 1.37 in
October 60.5°F 44.7°F — in 61.0°F 46.4°F 3.49 in
November 49.0°F 37.7°F — in 53.0°F 39.9°F 5.80 in
December 42.0°F 33.1°F — in 47.8°F 36.2°F 5.49 in
St. Helens overview
Full climate profile
 Seattle overview
Full climate profile