Oak Harbor (WA) Temperature by Month

The average annual maximum temperature in Oak Harbor, Washington State, United States of America is 14°C (57°F), with daytime highs ranging from 8°C (46°F) in December to 20°C (68°F) in August. This page covers monthly averages, day-night differences, and how Oak Harbor compares to cities worldwide.

The climate in Oak Harbor is known for significant temperature differences throughout the year. At night, this contrast is just as clear, with lows ranging from 11°C (52°F) in August to 2°C (36°F) in December.

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

Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM. August, the warmest month, sees 301 hours of sunshine.

The chart below shows the average temperature throughout the year:

Oak Harbor'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:

Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.

Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.

Shanghai, China averages 21°C (70°F) a year, with warm summers, mild winters, and a noticeable spring and autumn.

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

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 Oak Harbor this rarely lasts long on the ground.

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