Sunnyside (WA) Temperature by Month
Sunnyside in Washington State, United States of America sees significant seasonal temperature differences, with daytime highs between 3°C (37°F) in December and 33°C (91°F) in July, averaging 18°C (64°F) annually. Explore the full monthly breakdown below.
Sunnyside Monthly Temperatures
Visitors to Sunnyside will encounter a climate influenced by big temperature differences across the year. Nighttime temperatures range from 14°C (57°F) in July to -5°C (23°F) in December.
The chart below illustrates the average maximum day and minimum night temperatures in Sunnyside by month:
Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM.
The chart below shows the average temperature throughout the year:
Temperature: Sunnyside vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
very warm
warm
pleasant
moderate
cold
very cold
Sunnyside vs World: Temperature Compared
Sunnyside's average annual maximum temperature is 18°C (64°F). To put that in context, here's how it compares to a few well-known destinations:
Lisbon, Portugal averages 21°C (70°F) annually — warm summers, mild winters, and rain mainly in the cooler months.
Reykjavík, Iceland averages 9°C (48°F) a year — mild summers by Icelandic standards, but cold winters and frequent wind.
Beijing, China averages 20°C (68°F) annually, but with big seasonal swings — very cold winters and hot summers.
Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained — so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.
For more on Sunnyside's weather — including monthly rainfall, sunshine hours, and humidity — visit our Sunnyside climate page.
