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Monthly climate in Mattawa, Washington, United States

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification Mattawa features a cold semi-arid climate (BSk).Temperatures typically range between -1 °C (31 °F) and 25 °C (77 °F) through the year, but rarely can drop to -23 °C (-9 °F) or can rise to as high as 46 °C (115 °F).The average annual precipitation amounts to about 290 mm (11.4 inches) and receives 66 rainy days on the 1 mm (0.04 inches) threshold annually.Mattawa enjoys an average of 3133 hours of sunshine throughout the year, and daylight varies from 8 hours 35 minutes to 15 hours 46 minutes per day.

Monthly average temperatures in Mattawa, Washington, United States §

The warmest months in Mattawa are June, July and August, with daily mean temperatures ranging from 21 to 25 °C (70 - 77 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -1 to 0 °C (31 - 33 °F) throughout the day. On average each year, Mattawa experiences 94 days above 25 °C (77.0 °F) and 88 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Mattawa, Washington, 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 13°C
(56°F)		 17°C
(62°F)		 21°C
(70°F)		 31°C
(87°F)		 35°C
(95°F)		 46°C
(115°F)		 43°C
(109°F)		 41°C
(105°F)		 38°C
(101°F)		 31°C
(89°F)		 20°C
(69°F)		 18°C
(64°F)
Mean maximum 10°C
(51°F)		 12°C
(54°F)		 19°C
(66°F)		 25°C
(77°F)		 32°C
(90°F)		 35°C
(96°F)		 40°C
(104°F)		 40°C
(103°F)		 35°C
(95°F)		 26°C
(78°F)		 18°C
(65°F)		 12°C
(55°F)
Average high 3°C
(37°F)		 5°C
(41°F)		 11°C
(53°F)		 17°C
(63°F)		 23°C
(74°F)		 28°C
(82°F)		 33°C
(91°F)		 32°C
(90°F)		 26°C
(78°F)		 16°C
(62°F)		 8°C
(48°F)		 3°C
(38°F)
Daily mean -1°C
(31°F)		 0°C
(33°F)		 6°C
(43°F)		 11°C
(52°F)		 17°C
(63°F)		 21°C
(70°F)		 25°C
(77°F)		 25°C
(77°F)		 19°C
(66°F)		 11°C
(51°F)		 4°C
(40°F)		 0°C
(33°F)
Average low -4°C
(26°F)		 -3°C
(26°F)		 1°C
(34°F)		 5°C
(42°F)		 11°C
(52°F)		 14°C
(58°F)		 17°C
(63°F)		 17°C
(63°F)		 13°C
(55°F)		 6°C
(42°F)		 1°C
(34°F)		 -2°C
(28°F)
Mean minimum -11°C
(13°F)		 -11°C
(12°F)		 -6°C
(21°F)		 -0°C
(31°F)		 5°C
(41°F)		 9°C
(48°F)		 12°C
(54°F)		 11°C
(52°F)		 6°C
(44°F)		 -2°C
(29°F)		 -5°C
(24°F)		 -8°C
(18°F)
Minimum -23°C
(-9°F)		 -14°C
(7°F)		 -14°C
(7°F)		 -2°C
(28°F)		 3°C
(38°F)		 8°C
(46°F)		 11°C
(53°F)		 10°C
(51°F)		 3°C
(38°F)		 -6°C
(22°F)		 -8°C
(18°F)		 -12°C
(11°F)

Compare climate in Mattawa with other places

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

Monthly average precipitation in Mattawa, Washington, United States §

Mattawa usually has the most precipitation in January, February and December, with an average of 9 rainy days and 42 mm (1.6 inches) of precipitation per month.The driest months in Mattawa are June, July and August. On average, 4 mm (0.2 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Mattawa, Washington, 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) 45 (1.8) 43 (1.7) 27 (1.1) 26 (1.0) 17 (0.7) 7 (0.3) 1 (0.0) 5 (0.2) 14 (0.5) 33 (1.3) 35 (1.4) 38 (1.5)
Average precipitation days (≥ 1 mm) 10 9 7 6 5 2 0 1 3 6 8 9

Monthly sunshine hours in Mattawa, Washington, United States §

The sunniest months in Mattawa are June, July and August, when the sun shines an average of 12 hours 35 minutes a day.Least sunny months in Mattawa: January, November and December receive an average of 4 hours 5 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Mattawa, Washington, 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 89 165 243 297 358 380 414 362 290 245 161 125
Mean daily daylight hours 9h 1m 10h 19m 11h 57m 13h 37m 15h 3m 15h 46m 15h 22m 14h 5m 12h 29m 10h 49m 9h 21m 8h 35m

Solar UV radiation in Mattawa, Washington, United States §

Mattawa experiences the highest level of ultraviolet (UV) radiation in June, July and August, 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 Mattawa UV Index data.

Average daily maximum UV levels by month for Mattawa, Washington, 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) 2 3 5 6 8 9 10 9 7 5 3 2