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Monthly climate in Mount Vernon, Washington, United States

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification Mount Vernon features a warm-summer Mediterranean climate (Csb).Temperatures typically range between 2 °C (36 °F) and 18 °C (64 °F) through the year, but rarely can drop to -15 °C (6 °F) or can rise to as high as 36 °C (98 °F).The average annual precipitation amounts to about 1990 mm (78.3 inches) and receives 170 rainy days on the 1 mm (0.04 inches) threshold annually.Mount Vernon enjoys an average of 2778 hours of sunshine throughout the year, and daylight varies from 8 hours 21 minutes to 16 hours 1 minutes per day.

Monthly average temperatures in Mount Vernon, Washington, United States §

The warmest months in Mount Vernon are June, July and August, with daily mean temperatures ranging from 15 to 18 °C (59 - 64 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 2 to 3 °C (36 - 38 °F) throughout the day. On average each year, Mount Vernon experiences 13 days above 25 °C (77.0 °F) and 42 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Mount Vernon, 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 12°C
(54°F)		 12°C
(54°F)		 22°C
(72°F)		 21°C
(71°F)		 26°C
(78°F)		 36°C
(98°F)		 30°C
(86°F)		 33°C
(93°F)		 29°C
(84°F)		 23°C
(73°F)		 15°C
(60°F)		 12°C
(54°F)
Mean maximum 11°C
(51°F)		 10°C
(51°F)		 15°C
(58°F)		 18°C
(65°F)		 23°C
(73°F)		 26°C
(79°F)		 28°C
(82°F)		 30°C
(86°F)		 26°C
(78°F)		 18°C
(65°F)		 14°C
(57°F)		 10°C
(51°F)
Average high 6°C
(43°F)		 5°C
(42°F)		 9°C
(48°F)		 12°C
(53°F)		 16°C
(61°F)		 18°C
(65°F)		 21°C
(71°F)		 22°C
(72°F)		 19°C
(66°F)		 12°C
(55°F)		 9°C
(48°F)		 5°C
(42°F)
Daily mean 3°C
(38°F)		 2°C
(36°F)		 5°C
(42°F)		 8°C
(47°F)		 12°C
(54°F)		 15°C
(59°F)		 17°C
(63°F)		 18°C
(64°F)		 15°C
(59°F)		 9°C
(49°F)		 6°C
(43°F)		 3°C
(38°F)
Average low 1°C
(34°F)		 -0°C
(32°F)		 2°C
(36°F)		 5°C
(41°F)		 9°C
(48°F)		 11°C
(52°F)		 13°C
(56°F)		 14°C
(57°F)		 12°C
(53°F)		 6°C
(44°F)		 4°C
(39°F)		 1°C
(34°F)
Mean minimum -6°C
(21°F)		 -8°C
(18°F)		 -4°C
(26°F)		 -0°C
(32°F)		 5°C
(40°F)		 7°C
(46°F)		 10°C
(51°F)		 10°C
(50°F)		 7°C
(45°F)		 1°C
(34°F)		 -2°C
(29°F)		 -6°C
(21°F)
Minimum -11°C
(13°F)		 -15°C
(6°F)		 -6°C
(21°F)		 -2°C
(28°F)		 3°C
(37°F)		 6°C
(43°F)		 10°C
(50°F)		 9°C
(48°F)		 6°C
(43°F)		 -1°C
(31°F)		 -4°C
(25°F)		 -14°C
(8°F)

Compare climate in Mount Vernon with other places

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

Monthly average precipitation in Mount Vernon, Washington, United States §

Mount Vernon usually has the most precipitation in February, November and December, with an average of 19 rainy days and 276 mm (10.9 inches) of precipitation per month.The driest months in Mount Vernon are June, July and August. On average, 44 mm (1.7 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Mount Vernon, 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) 236 (9.3) 244 (9.6) 191 (7.5) 146 (5.8) 82 (3.2) 75 (3.0) 31 (1.2) 26 (1.0) 146 (5.8) 229 (9.0) 312 (12.3) 271 (10.7)
Average precipitation days (≥ 1 mm) 16 20 17 17 12 11 5 4 12 17 20 19

Monthly sunshine hours in Mount Vernon, Washington, United States §

The sunniest months in Mount Vernon are June, July and August, when the sun shines an average of 11 hours 42 minutes a day.Least sunny months in Mount Vernon: January, November and December receive an average of 3 hours 23 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Mount Vernon, 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 87 142 210 246 333 340 387 348 263 192 127 97
Mean daily daylight hours 8h 48m 10h 12m 11h 57m 13h 43m 15h 15m 16h 1m 15h 35m 14h 13m 12h 30m 10h 44m 9h 10m 8h 21m

Solar UV radiation in Mount Vernon, Washington, United States §

Mount Vernon 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 Mount Vernon UV Index data.

Average daily maximum UV levels by month for Mount Vernon, 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 7 5 2 2