What is the climate like in Eureka, CA?

Eureka has an annual average temperature of 52.6°F with about 40.4 inches of precipitation per year. Climate type: Warm-summer Mediterranean (Köppen Csb).

What is the hottest month in Eureka?

August is the warmest month in Eureka, with an average high of 64.0°F.

What is the coldest month in Eureka?

December is the coldest month in Eureka, with an average low of 40.0°F.

What month does Eureka get the most rain?

December is typically the wettest month in Eureka, with about 8.10 inches of precipitation.

What plant hardiness zone is Eureka in?

Eureka is approximately in USDA plant hardiness Zone 9b, based on the average annual extreme minimum temperature.

Eureka, CA

Climate overview — based on NOAA 1991-2020 normals from EUREKA WFO WOODLEY ISLAND, CA US.

Csb Warm-summer Mediterranean climate 9b USDA hardiness Zone 9b

Year-round temperatures (°F)

Avg high Avg low

Climate summary

Eureka has an annual average temperature of 52.6°F with about 40.4 inches of precipitation per year. The warmest month is August (average high 64.0°F), and the coldest is December (average low 40.0°F). December is typically the wettest month (8.10 in) and July the driest (0.18 in).

Annual swing

11.1°F

warmest to coldest month

Heating need

4,452

HDD/yr

Cooling need

CDD/yr

Best time to visit Eureka

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Monthly averages

Month	Avg High	Avg Low	Avg Temp	Precipitation	Snow	Rainy days
January	55.1°F	40.8°F	47.9°F	6.67 in	—	17
February	55.4°F	41.3°F	48.4°F	5.64 in	—	15
March	56.1°F	42.4°F	49.2°F	5.75 in	—	16
April	57.4°F	44.2°F	50.8°F	3.64 in	—	14
May	59.6°F	47.7°F	53.7°F	1.66 in	—	9
June	61.9°F	50.1°F	56.0°F	0.70 in	—	6
July	63.1°F	52.4°F	57.7°F	0.18 in	—	3
August	64.0°F	53.0°F	58.5°F	0.18 in	—	4
September	63.9°F	50.5°F	57.2°F	0.68 in	—	5
October	61.9°F	46.8°F	54.3°F	2.31 in	—	9
November	57.8°F	43.2°F	50.5°F	4.89 in	—	14
December	54.7°F	40.0°F	47.4°F	8.10 in	—	17