Boulder vs Castle Rock Climate
96%matchOn climate, Castle Rock is a 96% match for Boulder. Compared with Boulder, Castle Rock has 4°F (2°C) colder winter nights.
Boulder gets 17 in (421 mm) of rain a year and Castle Rock 15 in (377 mm). July is the warmest month in both, with highs of 89°F (32°C) in Boulder and 87°F (31°C) in Castle Rock.
Climate fingerprints: ring color = average temperature, thickness = rain. January at the top.
Month by month
Highs and lows (°F)
BoulderCastle Rocksolid = high, dashed = low
Rain (in per month)
BoulderCastle Rock
Monthly averages
| Month | High | Low | Rain | |||
|---|---|---|---|---|---|---|
| Boulder | Castle Rock | Boulder | Castle Rock | Boulder | Castle Rock | |
| Jan | 47°F(8°C) | 45°F(7°C) | 19°F(-7°C) | 14°F(-10°C) | 0.6 in(15 mm) | 0.4 in(11 mm) |
| Feb | 47°F(8°C) | 47°F(8°C) | 20°F(-7°C) | 16°F(-9°C) | 0.7 in(18 mm) | 0.6 in(14 mm) |
| Mar | 56°F(13°C) | 55°F(13°C) | 27°F(-3°C) | 24°F(-4°C) | 1.5 in(39 mm) | 1.1 in(28 mm) |
| Apr | 63°F(17°C) | 61°F(16°C) | 34°F(1°C) | 31°F(-1°C) | 2.3 in(58 mm) | 1.3 in(34 mm) |
| May | 72°F(22°C) | 71°F(21°C) | 43°F(6°C) | 40°F(4°C) | 2.6 in(66 mm) | 2.2 in(55 mm) |
| Jun | 83°F(28°C) | 82°F(28°C) | 52°F(11°C) | 49°F(10°C) | 1.7 in(42 mm) | 1.8 in(46 mm) |
| Jul | 89°F(32°C) | 87°F(31°C) | 57°F(14°C) | 55°F(13°C) | 1.7 in(43 mm) | 2.3 in(59 mm) |
| Aug | 87°F(31°C) | 85°F(29°C) | 56°F(13°C) | 53°F(12°C) | 1.3 in(34 mm) | 1.9 in(47 mm) |
| Sep | 79°F(26°C) | 78°F(25°C) | 47°F(8°C) | 45°F(7°C) | 1.4 in(36 mm) | 1.2 in(30 mm) |
| Oct | 66°F(19°C) | 66°F(19°C) | 36°F(2°C) | 33°F(0°C) | 1.2 in(30 mm) | 1.0 in(25 mm) |
| Nov | 53°F(12°C) | 54°F(12°C) | 26°F(-3°C) | 23°F(-5°C) | 1.0 in(25 mm) | 0.6 in(16 mm) |
| Dec | 47°F(8°C) | 45°F(7°C) | 20°F(-7°C) | 15°F(-10°C) | 0.6 in(15 mm) | 0.5 in(12 mm) |
1991–2020 averages, by calendar month.