Johnston, IA vs Seattle, WA

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

Johnston is cooler than Seattle (50.3°F vs 53.8°F annual avg) and similar rainfall to it (36.2 in vs 36.5 in per year). Johnston has a Hot-summer humid continental climate; Seattle a Warm-summer Mediterranean climate.

Johnston, IA

Annual avg
50.3°F
Annual precip
36.2 in
Warmest month
July (84.7°F)
Coldest month
January (13.1°F)
Annual swing
53.7°F
Pleasant months
2 / 12
Hot-summer humid continental Dfa USDA Zone 6b

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

Johnston

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 Johnston Seattle
High Low Precip High Low Precip
January 30.0°F 13.1°F 1.01 in 48.6°F 36.8°F 5.21 in
February 35.1°F 17.3°F 1.25 in 50.7°F 36.8°F 3.71 in
March 48.6°F 28.8°F 2.15 in 54.8°F 39.4°F 3.94 in
April 61.5°F 40.1°F 4.00 in 59.8°F 43.6°F 2.89 in
May 71.8°F 51.8°F 4.84 in 66.5°F 49.3°F 1.98 in
June 80.9°F 62.0°F 5.35 in 71.2°F 54.0°F 1.22 in
July 84.7°F 65.6°F 4.27 in 77.3°F 57.5°F 0.56 in
August 82.9°F 63.6°F 3.97 in 77.4°F 58.1°F 0.83 in
September 76.2°F 55.1°F 3.40 in 71.7°F 53.9°F 1.37 in
October 63.1°F 42.5°F 2.51 in 61.0°F 46.4°F 3.49 in
November 47.7°F 29.9°F 1.95 in 53.0°F 39.9°F 5.80 in
December 35.2°F 19.0°F 1.46 in 47.8°F 36.2°F 5.49 in
Johnston overview
Full climate profile
 Seattle overview
Full climate profile