Last updated: May 6, 2024
Under the Köppen–Geiger climate classification Castle Rock features a warm-summer Mediterranean climate (Csb).Temperatures typically range between 4 °C (40 °F) and 19 °C (66 °F) through the year, but rarely can drop to -9 °C (16 °F) or can rise to as high as 44 °C (112 °F).The average annual precipitation amounts to about 1390 mm (54.7 inches) and receives 152 rainy days on the 1 mm (0.04 inches) threshold annually.Castle Rock enjoys an average of 2496 hours of sunshine throughout the year, and daylight varies from 8 hours 40 minutes to 15 hours 42 minutes per day.
The warmest months in Castle Rock are July, August and September, with daily mean temperatures ranging from 16 to 19 °C (61 - 66 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 4 to 5 °C (40 - 41 °F) throughout the day. On average each year, Castle Rock experiences 41 days above 25 °C (77.0 °F) and 41 days below 0 °C (32.0 °F).
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Maximum | 15°C (59°F) | 15°C (60°F) | 24°C (75°F) | 29°C (85°F) | 30°C (86°F) | 44°C (112°F) | 36°C (96°F) | 38°C (100°F) | 34°C (93°F) | 24°C (76°F) | 17°C (63°F) | 14°C (57°F) |
Mean maximum | 13°C (55°F) | 13°C (55°F) | 19°C (66°F) | 24°C (76°F) | 28°C (82°F) | 33°C (91°F) | 32°C (90°F) | 35°C (96°F) | 31°C (88°F) | 21°C (70°F) | 16°C (62°F) | 13°C (55°F) |
Average high | 8°C (47°F) | 8°C (46°F) | 12°C (53°F) | 15°C (59°F) | 19°C (66°F) | 21°C (71°F) | 25°C (77°F) | 26°C (79°F) | 22°C (72°F) | 15°C (60°F) | 11°C (51°F) | 7°C (46°F) |
Daily mean | 5°C (41°F) | 4°C (40°F) | 7°C (45°F) | 10°C (50°F) | 13°C (56°F) | 16°C (61°F) | 18°C (65°F) | 19°C (66°F) | 16°C (61°F) | 10°C (51°F) | 7°C (45°F) | 4°C (40°F) |
Average low | 2°C (37°F) | 1°C (34°F) | 3°C (38°F) | 5°C (42°F) | 8°C (47°F) | 11°C (51°F) | 12°C (54°F) | 13°C (55°F) | 11°C (52°F) | 6°C (43°F) | 4°C (39°F) | 2°C (36°F) |
Mean minimum | -5°C (24°F) | -5°C (23°F) | -2°C (29°F) | 0°C (33°F) | 3°C (38°F) | 6°C (44°F) | 9°C (49°F) | 8°C (48°F) | 6°C (43°F) | -1°C (31°F) | -3°C (27°F) | -5°C (24°F) |
Minimum | -9°C (16°F) | -8°C (17°F) | -3°C (26°F) | -1°C (30°F) | 3°C (37°F) | 5°C (42°F) | 8°C (46°F) | 8°C (46°F) | 5°C (42°F) | -4°C (25°F) | -4°C (25°F) | -7°C (19°F) |
Compare temperature, precipitation, sunshine, UV index in Castle Rock, Washington, United States with other places around the world.
Castle Rock usually has the most precipitation in January, November and December, with an average of 18 rainy days and 190 mm (7.5 inches) of precipitation per month.The driest months in Castle Rock are June, July and August. On average, 26 mm (1.0 inches) of precipitation falls during these months.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Average precipitation mm (inches) | 190 (7.5) | 175 (6.9) | 150 (5.9) | 125 (4.9) | 74 (2.9) | 59 (2.3) | 10 (0.4) | 10 (0.4) | 84 (3.3) | 132 (5.2) | 179 (7.0) | 202 (8.0) |
Average precipitation days (≥ 1 mm) | 17 | 19 | 18 | 16 | 11 | 8 | 2 | 2 | 9 | 13 | 18 | 19 |
The sunniest months in Castle Rock are June, July and August, when the sun shines an average of 10 hours 31 minutes a day.Least sunny months in Castle Rock: January, February and December receive an average of 3 hours 11 minutes of sunshine daily.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean monthly sunshine hours | 80 | 116 | 190 | 215 | 275 | 303 | 346 | 318 | 247 | 189 | 119 | 93 |
Mean daily daylight hours | 9h 4m | 10h 21m | 11h 57m | 13h 35m | 14h 59m | 15h 42m | 15h 18m | 14h 3m | 12h 28m | 10h 50m | 9h 24m | 8h 40m |
Castle Rock experiences the highest level of ultraviolet (UV) radiation in May, June and July, when the maximum UV index can reach values of 9 - 10, which corresponds to the Very High category of sun exposure.January, February and December are in the Low / Moderate exposure category. In these months, the maximum values of the UV index do not exceed 3. For more detailed information, check out our hourly Castle Rock UV Index data.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
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UV Index (month maximum) | 2 | 3 | 5 | 6 | 9 | 10 | 9 | 8 | 7 | 5 | 3 | 2 |