Historical weather data, all-time temperature records, and monthly climate averages for Eureka, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Eureka is a coin-flip for rain — there's a 45% chance of precipitation based on 84 years of records. Expect a typical high around 56° and low around 44°, though this date has swung anywhere from a chilly 34° (2012) to a mild 69° (1985).
Eureka's weather is defined more by its narrowness than its extremes — the all-time hottest day only reached 87°, back in September 2017. Winter cold rarely bites hard either, with the record low sitting at 21° from December 1972, though a single December storm in 2002 dumped nearly 6.8 inches of rain in one day.
Eureka is one of the most temperature-stable cities in the country — monthly average highs barely budge, ranging from 54° in early January to just 64° at the peak in late August. If you're chasing the warmest, driest stretch, late summer through early fall is your window. Avoid the last week of December if you hate rain — it's the wettest week of the year, averaging nearly two inches.