Boulder, MT vs Phoenix, AZ

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

Boulder is cooler than Phoenix (42.6°F vs 72.5°F annual avg) and similar rainfall to it (10.8 in vs 8.9 in per year). Boulder has a Semi-arid (cold) climate; Phoenix a Desert (hot) climate.

Boulder, MT

Annual avg
42.6°F
Annual precip
10.8 in
Warmest month
July (82.5°F)
Coldest month
December (11.5°F)
Annual swing
42.9°F
Semi-arid (cold) BSk USDA Zone 6b

Phoenix, AZ

Annual avg
72.5°F
Annual precip
8.9 in
Warmest month
July (104.0°F)
Coldest month
December (42.7°F)
Annual swing
39.1°F
Pleasant months
2 / 12
Desert (hot) BWh USDA Zone 9b

Best months to visit each city

Boulder

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

Phoenix

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

Month-by-month comparison

Month Boulder Phoenix
High Low Precip High Low Precip
January 35.0°F 11.9°F 0.28 in 65.4°F 44.1°F 1.17 in
February 37.8°F 14.0°F 0.19 in 68.1°F 46.1°F 1.21 in
March 46.8°F 20.8°F 0.40 in 75.0°F 50.9°F 1.09 in
April 54.5°F 27.0°F 0.78 in 82.5°F 56.6°F 0.35 in
May 63.6°F 35.3°F 1.86 in 91.5°F 64.7°F 0.19 in
June 72.0°F 42.5°F 2.30 in 101.5°F 72.7°F 0.03 in
July 82.5°F 48.3°F 1.38 in 104.0°F 80.8°F 0.81 in
August 82.0°F 46.2°F 1.12 in 102.5°F 80.5°F 0.96 in
September 71.9°F 38.1°F 1.10 in 97.5°F 74.7°F 0.71 in
October 57.4°F 27.7°F 0.64 in 86.3°F 62.7°F 0.67 in
November 42.4°F 18.6°F 0.48 in 74.0°F 50.8°F 0.90 in
December 33.6°F 11.5°F 0.27 in 63.9°F 42.7°F 0.81 in
Boulder overview
Full climate profile
 Phoenix overview
Full climate profile