Arlington (WA) Temperature by Month

Arlington in Washington State, United States of America sees significant seasonal temperature differences, with daytime highs between 7°C (45°F) in December and 24°C (75°F) in August, averaging 15°C (59°F) annually. Explore the full monthly breakdown below.

In Arlington, temperatures differ significantly between summer and winter months. Nighttime lows reflect this range, dropping from 11°C (52°F) in August to 0°C (32°F) in December.

The chart below illustrates the average maximum day and minimum night temperatures in Arlington by month:

The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. August, the city's warmest month, gets 249 hours of sunshine.

The chart below shows the average temperature throughout the year:

Arlington's average annual maximum temperature is 15°C (59°F). To put that in context, here's how it compares to a few well-known destinations:

Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

Beijing, China averages 20°C (68°F) annually, but with big seasonal swings, very cold winters and hot summers.

Tokyo, Japan averages 21°C (70°F) a year, with hot summers, cool winters, and a well-defined cherry blossom spring.

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.

Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round, large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.

For more on Arlington's weather, including monthly rainfall, sunshine hours, and humidity, visit our Arlington climate page.