Historical weather data, all-time temperature records, and monthly climate averages for Oak Harbor, WA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 is a true coin-flip day in Oak Harbor — there's a 51% chance of rain, and 74 years of data back that up. Highs average 55°, though the date has swung from a chilly 30° low back in 1997 all the way to 70° just this year in 2025.
Oak Harbor's all-time extremes tell the story of a place that stays mild but isn't immune to drama — the thermometer has hit 88° in July and bottomed out at -1° in January 1950. The wettest single day on record dropped 3.03 inches back in September 1983, and a December 1996 storm buried the area under 9 inches of snow.
Summer is the clear sweet spot, with highs peaking around 67-68° in mid-July — warm, but rarely sweltering. Winters are cool and gray, with January highs averaging just 46°. If you want to dodge the rain, avoid late November, which is the wettest stretch of the year at about 0.7 inches per week.