Mukilteo (WA) Temperature by Month

The average annual maximum temperature in Mukilteo, Washington State, United States of America is 14°C (57°F), with daytime highs ranging from 7°C (45°F) in December to 23°C (73°F) in August. This page covers monthly averages, day-night differences, and how Mukilteo compares to cities worldwide.

Depending on the time of the year, temperatures range from warm to cold in Mukilteo. Nighttime lows follow the same pattern, ranging from 13°C (55°F) to 2°C (36°F).

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

Daily lows are most common between 4 AM and 6 AM. By 3 PM temperatures reach their daily high, driven by peak solar heating. August, the warmest month of the year, receives 280 hours of sunshine.

The chart below shows the average temperature throughout the year:

Mukilteo's average annual maximum temperature is 14°C (57°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.

Zermatt, Switzerland averages just 4°C (39°F) annually due to its altitude, with very cold winters and cool summers even at its warmest.

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

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Mukilteo, December is the coolest month, with average highs of 7°C (45°F) and humidity around 80%, considered very high. For a full picture, see our humidity page.

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.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Mukilteo this rarely lasts long on the ground.

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