Portola Valley, CA vs Seattle, WA

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

Portola Valley is warmer than Seattle (57.1°F vs 53.8°F annual avg) and wetter than it (42.2 in vs 36.5 in per year). Both cities share a Warm-summer Mediterranean climate (Csb).

Portola Valley, CA

Annual avg
57.1°F
Annual precip
42.2 in
Warmest month
August (80.9°F)
Coldest month
December (40.1°F)
Annual swing
22.7°F
Pleasant months
3 / 12
Warm-summer Mediterranean Csb USDA Zone 9b

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

Portola Valley

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 Portola Valley Seattle
High Low Precip High Low Precip
January 54.7°F 40.9°F 7.77 in 48.6°F 36.8°F 5.21 in
February 55.1°F 40.3°F 7.97 in 50.7°F 36.8°F 3.71 in
March 58.4°F 41.3°F 6.32 in 54.8°F 39.4°F 3.94 in
April 61.6°F 42.6°F 3.37 in 59.8°F 43.6°F 2.89 in
May 66.9°F 47.2°F 1.29 in 66.5°F 49.3°F 1.98 in
June 75.2°F 52.0°F 0.42 in 71.2°F 54.0°F 1.22 in
July 80.6°F 57.7°F 0.04 in 77.3°F 57.5°F 0.56 in
August 80.9°F 58.5°F 0.11 in 77.4°F 58.1°F 0.83 in
September 78.9°F 57.1°F 0.18 in 71.7°F 53.9°F 1.37 in
October 71.0°F 51.7°F 1.73 in 61.0°F 46.4°F 3.49 in
November 60.4°F 44.4°F 4.60 in 53.0°F 39.9°F 5.80 in
December 53.8°F 40.1°F 8.41 in 47.8°F 36.2°F 5.49 in
Portola Valley overview
Full climate profile
 Seattle overview
Full climate profile