Photo: Robert Campbell · CC BY-SA 3.0Eureka’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 63°, a January night drops to 42°, and snow is almost unheard of.
A year in Eureka at a glance
Each month’s typical high and low, and what it brings.
What stands out about Eureka’s climate
Compared with towns across the U.S., with Eureka’s place in California beside it.
What a year in Eureka feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 293 frost-free days a year
In half of years the last 32° night comes by February 22 and the first by December 7. Frost and day counts come from NOAA’s station at Eureka Wfo Woodley Island, CA, 0.8 miles from the town’s center, at about the same height.
The 2023 USDA map puts Eureka’s center in zone 9b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 29°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
About 48 inches of rain a year
December is the wettest month and July the driest. Rain falls on about 128 days a year. Snow is rare: about 0.0" in a normal year at Eureka Wfo Woodley Island, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Eureka
Nearly all of the work is heating: a normal year has almost no cooling days. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Eureka Wfo Woodley Island, CA.
Living with Eureka’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
293 frost-free days in zone 9b. The last frost comes by Feb 22 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Dec 7.
Months with highs of 62–84° and lows of 40° or more: July, August and September. 10 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Eureka from natural hazards, earthquakes are the largest share (68%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Eureka and its neighbors
Pine Hills the hottest July afternoons (66°, 3° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Eureka’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Eureka, CA | 42° | 63° | 48" | 0.0" |
| Coos Bay, OR | 40° | 66° | 61" | 0.2" |
| Port Angeles, WA | 37° | 69° | 28" | 0.4" |
| Makawao, HI | 53° | 75° | 23" | 0.0" |
| Nantucket, MA | 26° | 76° | 44" | 25" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Eureka averaged 1.4° warmer than the 1900s. The biggest change is in January (+2.1°).
A bigger shift than in 53% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Eureka compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Eureka’s place among California’s.
Eureka weather by month
Highs, lows and precipitation from NOAA’s grid at Eureka’s center; snow, wet days and snow on the ground from Eureka Wfo Woodley Island, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 55° | 42° | 7.9" | 0.0" | 17 | 0 | 44° – 54° |
| February | 56° | 42° | 6.8" | 0.0" | 15 | 0 | 44° – 53° |
| March | 56° | 43° | 6.9" | 0.0" | 16 | 0 | 46° – 53° |
| April | 57° | 44° | 4.3" | 0.0" | 14 | 0 | 48° – 55° |
| May | 59° | 47° | 2.1" | 0.0" | 9 | 0 | 50° – 57° |
| June | 62° | 49° | 0.8" | 0.0" | 6 | 0 | 51° – 57° |
| July | 63° | 51° | 0.2" | 0.0" | 3 | 0 | 54° – 60° |
| August | 64° | 51° | 0.2" | 0.0" | 4 | 0 | 56° – 61° |
| September | 63° | 50° | 0.7" | 0.0" | 5 | 0 | 54° – 60° |
| October | 61° | 48° | 2.8" | 0.0" | 9 | 0 | 51° – 59° |
| November | 58° | 44° | 5.7" | 0.0" | 14 | 0 | 45° – 55° |
| December | 55° | 41° | 9.4" | 0.0" | 17 | 0 | 44° – 53° |
| Year | 59° | 46° | 47.6" | 0.0" | 128 | 0 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 44° to 54°. August is the most reliable, staying within 5°.
Where Eureka’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Eureka’s center.
- Snow: Eureka Wfo Woodley Island, CA (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Eureka Wfo Woodley Island, CA, 0.8 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Eureka’s climate
What is the weather like in Eureka?
A typical July afternoon reaches 63°, a January night drops to 42°, and snow is almost unheard of. Milder January nights than 91% of U.S. towns; cooler July afternoons than all but 11 U.S. towns.
How cold does it get in Eureka in winter?
December nights average 41°. About 8 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 44°.
How much snow does Eureka get?
About 0.0 inches in a normal winter at Eureka Wfo Woodley Island, CA, so most winters see none.
How hot does it get in Eureka?
July, with a typical high of 63°. 90° days are rare: none in a normal year at Eureka Wfo Woodley Island, CA.
When is the first and last frost in Eureka?
In half of years the last spring frost (32°) comes by February 22 and the first fall frost by December 7, about 293 frost-free days, at Eureka Wfo Woodley Island, CA.
What growing zone is Eureka in?
Zone 9b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 29°.
What is the best time of year to visit Eureka?
By one simple rule (highs of 62–84° and lows of 40° or more), July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Eureka getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 53% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Eureka.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.