nomadseason

Monthly climate in Marietta, Washington, United States

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification Marietta features a oceanic climate (Cfb).Temperatures typically range between 4 °C (39 °F) and 18 °C (64 °F) through the year, but rarely can drop to -12 °C (10 °F) or can rise to as high as 35 °C (95 °F).The average annual precipitation amounts to about 1647 mm (64.8 inches) and receives 158 rainy days on the 1 mm (0.04 inches) threshold annually.Marietta enjoys an average of 2751 hours of sunshine throughout the year, and daylight varies from 8 hours 19 minutes to 16 hours 4 minutes per day.

Monthly average temperatures in Marietta, Washington, United States §

The warmest months in Marietta are July, August and September, with daily mean temperatures ranging from 15 to 18 °C (60 - 64 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 4 to 5 °C (39 - 41 °F) throughout the day. On average each year, Marietta experiences 4 days above 25 °C (77.0 °F) and 13 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Marietta, 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)		 13°C
(56°F)		 20°C
(67°F)		 21°C
(69°F)		 24°C
(75°F)		 35°C
(95°F)		 27°C
(80°F)		 30°C
(86°F)		 27°C
(81°F)		 19°C
(66°F)		 16°C
(62°F)		 12°C
(55°F)
Mean maximum 12°C
(53°F)		 11°C
(52°F)		 14°C
(58°F)		 17°C
(63°F)		 20°C
(68°F)		 24°C
(75°F)		 25°C
(77°F)		 27°C
(81°F)		 24°C
(75°F)		 17°C
(62°F)		 14°C
(58°F)		 11°C
(52°F)
Average high 7°C
(45°F)		 6°C
(43°F)		 9°C
(48°F)		 11°C
(53°F)		 14°C
(58°F)		 17°C
(63°F)		 20°C
(67°F)		 21°C
(69°F)		 18°C
(64°F)		 13°C
(55°F)		 9°C
(49°F)		 6°C
(44°F)
Daily mean 5°C
(41°F)		 4°C
(39°F)		 6°C
(44°F)		 9°C
(48°F)		 12°C
(53°F)		 15°C
(59°F)		 17°C
(63°F)		 18°C
(64°F)		 15°C
(60°F)		 11°C
(51°F)		 8°C
(46°F)		 5°C
(41°F)
Average low 3°C
(38°F)		 2°C
(36°F)		 4°C
(39°F)		 6°C
(43°F)		 9°C
(49°F)		 12°C
(54°F)		 15°C
(59°F)		 15°C
(60°F)		 13°C
(56°F)		 8°C
(47°F)		 6°C
(43°F)		 3°C
(38°F)
Mean minimum -3°C
(28°F)		 -3°C
(27°F)		 0°C
(32°F)		 2°C
(36°F)		 6°C
(43°F)		 9°C
(48°F)		 12°C
(54°F)		 12°C
(55°F)		 9°C
(49°F)		 4°C
(39°F)		 1°C
(34°F)		 -3°C
(27°F)
Minimum -7°C
(20°F)		 -6°C
(22°F)		 -1°C
(31°F)		 2°C
(35°F)		 5°C
(41°F)		 8°C
(47°F)		 11°C
(53°F)		 10°C
(51°F)		 7°C
(46°F)		 2°C
(36°F)		 0°C
(33°F)		 -12°C
(10°F)

Compare climate in Marietta with other places

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

Monthly average precipitation in Marietta, Washington, United States §

Marietta usually has the most precipitation in January, November and December, with an average of 17 rainy days and 229 mm (9.0 inches) of precipitation per month.The driest months in Marietta are June, July and August. On average, 35 mm (1.4 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Marietta, 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) 199 (7.8) 185 (7.3) 156 (6.2) 127 (5.0) 76 (3.0) 58 (2.3) 27 (1.1) 19 (0.8) 125 (4.9) 186 (7.3) 261 (10.3) 227 (8.9)
Average precipitation days (≥ 1 mm) 15 19 17 15 11 10 4 3 11 16 19 18

Monthly sunshine hours in Marietta, Washington, United States §

The sunniest months in Marietta are June, July and August, when the sun shines an average of 11 hours 42 minutes a day.Least sunny months in Marietta: January, November and December receive an average of 3 hours 21 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Marietta, 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 86 140 206 240 332 341 388 347 257 186 124 97
Mean daily daylight hours 8h 46m 10h 11m 11h 57m 13h 44m 15h 17m 16h 4m 15h 38m 14h 14m 12h 30m 10h 43m 9h 8m 8h 19m

Solar UV radiation in Marietta, Washington, United States §

Marietta experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 8 - 9, which corresponds to the Very High category of sun exposure.January, November and December are in the Low exposure category. In these months, the maximum values of the UV index do not exceed 2. For more detailed information, check out our hourly Marietta UV Index data.

Average daily maximum UV levels by month for Marietta, 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 9 8 6 4 2 1