Sunnyside (WA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Sunnyside.
Climate overview of Sunnyside
Sunnyside, Washington State, United States of America, sees big temperature differences between seasons, with July peaking at 33°C (91°F) and December dropping to 3°C (37°F).
Rain/snowfall is extremely rare, with only 182 mm (7.2 in) falling across the entire year.
Sunnyside Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Sunnyside - and find the best time to visit.
Monthly Temperature in Sunnyside
Visitors to Sunnyside can expect significant temperature changes throughout the year. Average maximum daytime temperatures range from a very warm 33°C (91°F) in July, the warmest time of the year, to a chilly 3°C (37°F) during cooler months like December.
At night, you can expect temperatures ranging from 14°C (57°F) in July to around -5°C (23°F) during December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Sunnyside
Sunnyside experiences desert-like conditions in terms of precipitation with almost no rain/snowfall, generally receiving 182 mm (7.2 in) annually. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, December it receives low snow/rainfall, averaging 29 mm (1.1 in) of precipitation, recorded across 10 snowy/rainy days. In contrast, the driest month July brings less rainfall, with 2.2 mm (0.1 in) over 2 rainy days. For more details, please visit our Sunnyside Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Best Time to Visit Sunnyside
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: April, May, June, September and October
- Warmest weather: July and August
- Fewest rainy days: July, August and September
- Seasonal pattern: Very little rainfall year-round, with very warm summers and cold winters
- Coldest conditions: December, with freezing nights around -5°C (23°F).
Frequently asked questions about the climate in Sunnyside
What is the best time to visit Sunnyside?
April, May, June, September and October typically offer the most optimal weather in Sunnyside. In contrast, January and December tend to have less optimal conditions. Sunnyside has very little rainfall year-round, with very warm summers and cold winters.
What temperatures can I expect in Sunnyside?
Daytime highs range from 3°C (37°F) in December to 33°C (91°F) in July. Nighttime lows range from -5°C (23°F) to 14°C (57°F). Temperatures vary considerably through the year.
How much rain does Sunnyside get?
Annual rainfall is around 182 mm (7.2 in). December is the wettest month with 29 mm (1.1 in), while July is the driest with 2.2 mm (0.1 in). In the coldest months, precipitation may fall as snow/rain.
Sunnyside 3-Day Forecast
Sunnyside on the map
Sunnyside is highlighted - select any city to see its climate.
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