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

Best Time to Visit Sunnyside

During April, May, June, September and October, Sunnyside experiences its best dry weather, with temperatures between 18°C (65°F) and 27°C (81°F). The consistently dry conditions mean abundant sunshine for your visit.

Make the most of the clear weather, but remember to protect yourself from the sun and stay well-hydrated.

Looking for inspiration on where to travel this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.

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 a distinct dry season from January to December.

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 (WA) 3-Day Forecast

Sunnyside on the map

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Popular this month

Where to go in July — average daytime high across popular destinations.

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