Castalia, IA vs Seattle, WA

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

Castalia is cooler than Seattle (46°F vs 53.8°F annual avg) and similar rainfall to it (38.9 in vs 36.5 in per year). Castalia has a Hot-summer humid continental climate; Seattle a Warm-summer Mediterranean climate.

Castalia, IA

Annual avg
46°F
Annual precip
38.9 in
Warmest month
July (82.8°F)
Coldest month
January (7.4°F)
Annual swing
55.3°F
Pleasant months
1 / 12
Hot-summer humid continental Dfa USDA Zone 6a

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

Castalia

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 Castalia Seattle
High Low Precip High Low Precip
January 25.7°F 7.4°F 1.12 in 48.6°F 36.8°F 5.21 in
February 29.9°F 10.5°F 1.21 in 50.7°F 36.8°F 3.71 in
March 43.0°F 22.4°F 2.09 in 54.8°F 39.4°F 3.94 in
April 57.5°F 34.0°F 4.14 in 59.8°F 43.6°F 2.89 in
May 69.4°F 46.9°F 4.99 in 66.5°F 49.3°F 1.98 in
June 79.0°F 57.8°F 5.88 in 71.2°F 54.0°F 1.22 in
July 82.8°F 60.9°F 4.52 in 77.3°F 57.5°F 0.56 in
August 80.8°F 58.2°F 4.36 in 77.4°F 58.1°F 0.83 in
September 74.0°F 49.2°F 3.96 in 71.7°F 53.9°F 1.37 in
October 60.6°F 37.0°F 3.00 in 61.0°F 46.4°F 3.49 in
November 44.7°F 25.5°F 2.10 in 53.0°F 39.9°F 5.80 in
December 31.4°F 14.0°F 1.57 in 47.8°F 36.2°F 5.49 in
Castalia overview
Full climate profile
 Seattle overview
Full climate profile