Helena, MT vs Seattle, WA

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

Helena is cooler than Seattle (45.5°F vs 53.8°F annual avg) and drier than it (11.4 in vs 36.5 in per year). Helena has a Semi-arid (cold) climate; Seattle a Warm-summer Mediterranean climate.

Helena, MT

Annual avg
45.5°F
Annual precip
11.4 in
Warmest month
July (86.1°F)
Coldest month
January (13.5°F)
Annual swing
47.6°F
Semi-arid (cold) BSk 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

Helena

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 Helena Seattle
High Low Precip High Low Precip
January 32.4°F 13.5°F 0.39 in 48.6°F 36.8°F 5.21 in
February 37.2°F 17.2°F 0.42 in 50.7°F 36.8°F 3.71 in
March 47.5°F 24.6°F 0.52 in 54.8°F 39.4°F 3.94 in
April 56.7°F 32.4°F 1.02 in 59.8°F 43.6°F 2.89 in
May 66.4°F 41.5°F 1.95 in 66.5°F 49.3°F 1.98 in
June 74.7°F 48.7°F 2.21 in 71.2°F 54.0°F 1.22 in
July 86.1°F 55.1°F 1.06 in 77.3°F 57.5°F 0.56 in
August 84.6°F 52.9°F 1.04 in 77.4°F 58.1°F 0.83 in
September 73.3°F 44.6°F 0.96 in 71.7°F 53.9°F 1.37 in
October 57.6°F 33.5°F 0.78 in 61.0°F 46.4°F 3.49 in
November 42.8°F 22.8°F 0.59 in 53.0°F 39.9°F 5.80 in
December 32.6°F 14.2°F 0.46 in 47.8°F 36.2°F 5.49 in
Helena overview
Full climate profile
 Seattle overview
Full climate profile