Last updated: May 6, 2024
Under the Köppen–Geiger climate classification Rochester features a warm-summer Mediterranean climate (Csb).Temperatures typically range between 4 °C (40 °F) and 19 °C (66 °F) through the year, but rarely can drop to -8 °C (18 °F) or can rise to as high as 43 °C (109 °F).The average annual precipitation amounts to about 1362 mm (53.6 inches) and receives 153 rainy days on the 1 mm (0.04 inches) threshold annually.Rochester enjoys an average of 2558 hours of sunshine throughout the year, and daylight varies from 8 hours 36 minutes to 15 hours 46 minutes per day.
The warmest months in Rochester are July, August and September, with daily mean temperatures ranging from 16 to 19 °C (61 - 66 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 4 to 5 °C (40 - 41 °F) throughout the day. On average each year, Rochester experiences 38 days above 25 °C (77.0 °F) and 40 days below 0 °C (32.0 °F).
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Maximum | 15°C (59°F) | 14°C (58°F) | 25°C (77°F) | 28°C (83°F) | 30°C (86°F) | 43°C (109°F) | 35°C (95°F) | 37°C (98°F) | 32°C (91°F) | 24°C (76°F) | 17°C (63°F) | 13°C (56°F) |
Mean maximum | 13°C (55°F) | 12°C (54°F) | 19°C (66°F) | 23°C (74°F) | 27°C (81°F) | 32°C (90°F) | 32°C (91°F) | 35°C (95°F) | 29°C (85°F) | 20°C (69°F) | 16°C (61°F) | 13°C (55°F) |
Average high | 8°C (47°F) | 8°C (46°F) | 11°C (53°F) | 14°C (58°F) | 18°C (65°F) | 21°C (70°F) | 25°C (77°F) | 25°C (78°F) | 21°C (71°F) | 15°C (59°F) | 10°C (51°F) | 7°C (45°F) |
Daily mean | 5°C (41°F) | 4°C (40°F) | 7°C (45°F) | 10°C (49°F) | 13°C (56°F) | 16°C (60°F) | 18°C (65°F) | 19°C (66°F) | 16°C (61°F) | 10°C (51°F) | 7°C (45°F) | 5°C (40°F) |
Average low | 3°C (37°F) | 1°C (35°F) | 3°C (38°F) | 5°C (41°F) | 8°C (47°F) | 10°C (51°F) | 12°C (54°F) | 13°C (55°F) | 11°C (52°F) | 6°C (43°F) | 4°C (40°F) | 2°C (36°F) |
Mean minimum | -4°C (25°F) | -5°C (23°F) | -2°C (28°F) | -0°C (32°F) | 3°C (38°F) | 6°C (43°F) | 9°C (48°F) | 9°C (48°F) | 5°C (42°F) | -0°C (32°F) | -2°C (28°F) | -5°C (24°F) |
Minimum | -8°C (18°F) | -8°C (19°F) | -3°C (27°F) | -3°C (28°F) | 2°C (36°F) | 5°C (42°F) | 8°C (47°F) | 7°C (45°F) | 4°C (40°F) | -3°C (27°F) | -4°C (25°F) | -6°C (21°F) |
Compare temperature, precipitation, sunshine, UV index in Rochester, Washington, United States with other places around the world.
Rochester usually has the most precipitation in January, November and December, with an average of 18 rainy days and 189 mm (7.4 inches) of precipitation per month.The driest months in Rochester are June, July and August. On average, 27 mm (1.1 inches) of precipitation falls during these months.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Average precipitation mm (inches) | 186 (7.3) | 169 (6.7) | 137 (5.4) | 119 (4.7) | 71 (2.8) | 54 (2.1) | 12 (0.5) | 15 (0.6) | 88 (3.5) | 132 (5.2) | 181 (7.1) | 198 (7.8) |
Average precipitation days (≥ 1 mm) | 17 | 19 | 17 | 16 | 10 | 8 | 3 | 3 | 10 | 13 | 17 | 20 |
The sunniest months in Rochester are June, July and August, when the sun shines an average of 10 hours 44 minutes a day.Least sunny months in Rochester: January, November and December receive an average of 3 hours 12 minutes of sunshine daily.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean monthly sunshine hours | 81 | 120 | 200 | 223 | 287 | 310 | 352 | 324 | 251 | 193 | 119 | 94 |
Mean daily daylight hours | 9h 1m | 10h 19m | 11h 57m | 13h 37m | 15h 3m | 15h 46m | 15h 22m | 14h 5m | 12h 28m | 10h 49m | 9h 21m | 8h 36m |
Rochester experiences the highest level of ultraviolet (UV) radiation in May, June and July, when the maximum UV index can reach values of 9 - 9, 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 Rochester UV Index data.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
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UV Index (month maximum) | 2 | 3 | 5 | 6 | 9 | 9 | 9 | 8 | 7 | 5 | 3 | 2 |