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Monthly climate in Clayton, California, United States

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification Clayton features a warm-summer Mediterranean climate (Csb).Temperatures typically range between 10 °C (50 °F) and 20 °C (69 °F) through the year, but rarely can drop to -1 °C (30 °F) or can rise to as high as 42 °C (107 °F).The average annual precipitation amounts to about 443 mm (17.4 inches) and receives 45 rainy days on the 1 mm (0.04 inches) threshold annually.Clayton enjoys an average of 3453 hours of sunshine throughout the year, and daylight varies from 9 hours 33 minutes to 14 hours 44 minutes per day.

Monthly average temperatures in Clayton, California, United States §

The warmest months in Clayton are July, August and September, with daily mean temperatures ranging from 20 to 20 °C (68 - 69 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 10 to 11 °C (50 - 53 °F) throughout the day. On average each year, Clayton experiences 117 days above 25 °C (77.0 °F) and 0 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Clayton, California, United States.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to June 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Maximum 26°C
(78°F)		 27°C
(80°F)		 30°C
(85°F)		 32°C
(91°F)		 36°C
(98°F)		 39°C
(103°F)		 37°C
(98°F)		 41°C
(106°F)		 42°C
(107°F)		 35°C
(95°F)		 29°C
(84°F)		 24°C
(75°F)
Mean maximum 20°C
(67°F)		 23°C
(73°F)		 27°C
(80°F)		 30°C
(87°F)		 33°C
(92°F)		 36°C
(98°F)		 34°C
(94°F)		 37°C
(98°F)		 37°C
(100°F)		 32°C
(89°F)		 25°C
(77°F)		 20°C
(68°F)
Average high 15°C
(59°F)		 17°C
(63°F)		 19°C
(66°F)		 22°C
(71°F)		 25°C
(76°F)		 28°C
(82°F)		 28°C
(83°F)		 28°C
(83°F)		 28°C
(83°F)		 25°C
(78°F)		 19°C
(67°F)		 15°C
(58°F)
Daily mean 10°C
(50°F)		 11°C
(53°F)		 13°C
(55°F)		 15°C
(59°F)		 17°C
(63°F)		 20°C
(68°F)		 20°C
(68°F)		 20°C
(69°F)		 20°C
(69°F)		 18°C
(64°F)		 13°C
(56°F)		 10°C
(50°F)
Average low 6°C
(44°F)		 6°C
(44°F)		 8°C
(46°F)		 10°C
(50°F)		 12°C
(53°F)		 14°C
(57°F)		 14°C
(57°F)		 15°C
(59°F)		 14°C
(58°F)		 11°C
(53°F)		 8°C
(47°F)		 6°C
(43°F)
Mean minimum 0°C
(33°F)		 1°C
(34°F)		 3°C
(37°F)		 5°C
(42°F)		 9°C
(48°F)		 11°C
(52°F)		 12°C
(54°F)		 12°C
(54°F)		 10°C
(50°F)		 6°C
(43°F)		 4°C
(39°F)		 2°C
(37°F)
Minimum -1°C
(30°F)		 0°C
(32°F)		 2°C
(36°F)		 4°C
(40°F)		 6°C
(43°F)		 10°C
(50°F)		 12°C
(53°F)		 12°C
(54°F)		 8°C
(47°F)		 4°C
(39°F)		 2°C
(37°F)		 2°C
(36°F)

Compare climate in Clayton with other places

Compare temperature, precipitation, sunshine, UV index in Clayton, California, United States with other places around the world.

Monthly average precipitation in Clayton, California, United States §

Clayton usually has the most precipitation in January, February and December, with an average of 7 rainy days and 87 mm (3.4 inches) of precipitation per month.The driest months in Clayton are July, August and September. On average, 0 mm (0.0 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Clayton, California, United States.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average precipitation mm (inches) 99 (3.9) 89 (3.5) 72 (2.8) 31 (1.2) 16 (0.6) 1 (0.1) 0 (0.0) 0 (0.0) 1 (0.0) 23 (0.9) 37 (1.5) 75 (2.9)
Average precipitation days (≥ 1 mm) 8 7 9 5 2 0 0 0 0 1 5 8

Monthly sunshine hours in Clayton, California, United States §

The sunniest months in Clayton are May, June and July, when the sun shines an average of 12 hours 21 minutes a day.Least sunny months in Clayton: January, February and December receive an average of 6 hours 15 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Clayton, California, United States.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean monthly sunshine hours 153 219 266 301 364 381 390 354 313 284 227 196
Mean daily daylight hours 9h 51m 10h 47m 11h 59m 13h 12m 14h 14m 14h 44m 14h 28m 13h 32m 12h 22m 11h 9m 10h 5m 9h 33m

Solar UV radiation in Clayton, California, United States §

Clayton 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 Clayton UV Index data.

Average daily maximum UV levels by month for Clayton, California, United States.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2022 to January 2023.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
UV Index (month maximum) 3 5 8 9 10 11 11 10 9 6 4 3