Last updated: May 6, 2024
Under the Köppen–Geiger climate classification Half Moon Bay features a warm-summer Mediterranean climate (Csb).Temperatures typically range between 11 °C (53 °F) and 16 °C (62 °F) through the year, but rarely can drop to 5 °C (41 °F) or can rise to as high as 31 °C (88 °F).The average annual precipitation amounts to about 515 mm (20.3 inches) and receives 53 rainy days on the 1 mm (0.04 inches) threshold annually.Half Moon Bay enjoys an average of 3285 hours of sunshine throughout the year, and daylight varies from 9 hours 36 minutes to 14 hours 41 minutes per day.
The warmest months in Half Moon Bay are August, September and October, with daily mean temperatures ranging from 15 to 16 °C (60 - 62 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 11 to 12 °C (53 - 53 °F) throughout the day. On average each year, Half Moon Bay experiences 1 days above 25 °C (77.0 °F) and 0 days below 0 °C (32.0 °F).
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Maximum | 20°C (68°F) | 20°C (69°F) | 19°C (67°F) | 25°C (78°F) | 21°C (69°F) | 27°C (81°F) | 20°C (69°F) | 24°C (76°F) | 31°C (88°F) | 27°C (80°F) | 21°C (70°F) | 19°C (67°F) |
Mean maximum | 16°C (62°F) | 18°C (64°F) | 18°C (65°F) | 20°C (69°F) | 19°C (66°F) | 21°C (70°F) | 20°C (67°F) | 22°C (71°F) | 25°C (77°F) | 25°C (76°F) | 19°C (67°F) | 17°C (63°F) |
Average high | 13°C (56°F) | 14°C (57°F) | 14°C (57°F) | 14°C (58°F) | 15°C (59°F) | 17°C (62°F) | 17°C (63°F) | 18°C (65°F) | 19°C (67°F) | 18°C (65°F) | 16°C (61°F) | 14°C (57°F) |
Daily mean | 11°C (53°F) | 11°C (53°F) | 12°C (53°F) | 12°C (55°F) | 13°C (56°F) | 15°C (58°F) | 15°C (59°F) | 16°C (61°F) | 16°C (62°F) | 15°C (60°F) | 13°C (56°F) | 12°C (53°F) |
Average low | 10°C (49°F) | 9°C (49°F) | 10°C (50°F) | 11°C (51°F) | 11°C (52°F) | 13°C (55°F) | 13°C (55°F) | 14°C (57°F) | 14°C (58°F) | 13°C (56°F) | 11°C (53°F) | 10°C (50°F) |
Mean minimum | 7°C (44°F) | 6°C (43°F) | 7°C (46°F) | 8°C (47°F) | 10°C (50°F) | 11°C (52°F) | 12°C (53°F) | 12°C (54°F) | 12°C (54°F) | 10°C (51°F) | 9°C (48°F) | 7°C (45°F) |
Minimum | 5°C (41°F) | 5°C (41°F) | 7°C (44°F) | 7°C (45°F) | 9°C (48°F) | 10°C (51°F) | 11°C (51°F) | 11°C (53°F) | 11°C (52°F) | 9°C (49°F) | 7°C (45°F) | 6°C (44°F) |
Compare temperature, precipitation, sunshine, UV index in Half Moon Bay, California, United States with other places around the world.
Half Moon Bay usually has the most precipitation in January, February and December, with an average of 9 rainy days and 98 mm (3.9 inches) of precipitation per month.The driest months in Half Moon Bay are July, August and September. On average, 3 mm (0.1 inches) of precipitation falls during these months.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Average precipitation mm (inches) | 102 (4.0) | 101 (4.0) | 77 (3.0) | 34 (1.3) | 22 (0.9) | 4 (0.2) | 3 (0.1) | 3 (0.1) | 3 (0.1) | 27 (1.1) | 48 (1.9) | 92 (3.6) |
Average precipitation days (≥ 1 mm) | 9 | 9 | 11 | 5 | 2 | 0 | 0 | 0 | 0 | 2 | 5 | 10 |
The sunniest months in Half Moon Bay are May, June and July, when the sun shines an average of 11 hours 22 minutes a day.Least sunny months in Half Moon Bay: January, February and December receive an average of 6 hours 10 minutes of sunshine daily.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean monthly sunshine hours | 151 | 215 | 262 | 296 | 341 | 355 | 349 | 319 | 298 | 275 | 224 | 194 |
Mean daily daylight hours | 9h 54m | 10h 49m | 11h 59m | 13h 11m | 14h 11m | 14h 41m | 14h 25m | 13h 31m | 12h 22m | 11h 10m | 10h 8m | 9h 36m |
Half Moon Bay experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 10 - 11, which corresponds to the Very High / Extreme category of sun exposure.January, November and December are in the Moderate exposure category. In these months, the maximum values of the UV index do not exceed 4. For more detailed information, check out our hourly Half Moon Bay UV Index data.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
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UV Index (month maximum) | 3 | 5 | 8 | 9 | 10 | 11 | 11 | 10 | 9 | 7 | 4 | 3 |