Castle Rock Climate by Month
Castle Rock, Colorado, United States
Hot summers and cold winters, with rain spread through the year.
Castle Rock has hot summers and cold winters, with rain spread through the year. Afternoon highs range from 45°F (7°C) in December to 87°F (31°C) in July, and January nights average 14°F (-10°C). About 15 in (377 mm) of rain falls in a typical year, with no clear rainy season.
- Warmest month
- 87°F(31°C)
- Average high, July
- Coldest nights
- 14°F(-10°C)
- Average low, January
- Rain per year
- 15 in(377 mm)
- No clear rainy season
- Humidity
- 46%
- Sunniest: June
Best and worst months in Castle Rock
Best for weatherSeptember is the best time for weather in Castle Rock: highs near 78°F (25°C) and about 1.2 in (30 mm) of rain a month.
Least pleasantDecember and January are the least pleasant; December is the coldest, with highs of only 45°F (7°C).
Comfort combines how close the afternoon high is to 75°F (24°C) with how much rain falls and how humid it is. See where the weather is best in September.
Temperature and rain through the year
Highs and lows (°F)
Average highAverage low
Rain (in per month)
Castle Rock weather by month
| Month | High | Low | Rain | Humidity | Sun |
|---|---|---|---|---|---|
| JanJanuary | 45°F(7°C) | 14°F(-10°C) | 0.4 in(11 mm) | 54% | 2.4 |
| FebFebruary | 47°F(8°C) | 16°F(-9°C) | 0.6 in(14 mm) | 50% | 3.3 |
| MarMarch | 55°F(13°C) | 24°F(-4°C) | 1.1 in(28 mm) | 49% | 4.7 |
| AprApril | 61°F(16°C) | 31°F(-1°C) | 1.3 in(34 mm) | 38% | 5.4 |
| MayMay | 71°F(21°C) | 40°F(4°C) | 2.2 in(55 mm) | 47% | 6.5 |
| JunJune | 82°F(28°C) | 49°F(10°C) | 1.8 in(46 mm) | 37% | 7.0 |
| JulJuly | 87°F(31°C) | 55°F(13°C) | 2.3 in(59 mm) | 43% | 7.0 |
| AugAugust | 85°F(29°C) | 53°F(12°C) | 1.9 in(47 mm) | 45% | 6.1 |
| SepSeptemberBest | 78°F(25°C) | 45°F(7°C) | 1.2 in(30 mm) | 43% | 5.2 |
| OctOctober | 66°F(19°C) | 33°F(0°C) | 1.0 in(25 mm) | 42% | 3.8 |
| NovNovember | 54°F(12°C) | 23°F(-5°C) | 0.6 in(16 mm) | 50% | 2.6 |
| DecDecember | 45°F(7°C) | 15°F(-10°C) | 0.5 in(12 mm) | 54% | 2.2 |
1991–2020 averages. Sun is solar radiation in kWh/m² per day. Highlighted: the most comfortable months.
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