Eureka in Winter
In winter (December, January and February), Eureka sees average daytime highs around 53°F and overnight lows near 47°F, with 24.3 in of rain over about 44 wet days across the season. It is the coldest season of the year and the wettest season of the year.
Across winter, daytime highs hold fairly steady around 53°F. The sky is clear or mostly clear about 23% of the time across winter, and the air most often feels dry.
Winter is Eureka's weakest season of the year to visit on our travel score. Eureka has little temperature swing across the year, so its calendar seasons blur — the season framing matters less here than for a place with four distinct seasons. For the whole year in context, see Eureka's year-round climate.
- Avg daytime high
- 53°F
- coldest season of the year
- Avg overnight low
- 47°F
- Rainfall
- 24.3 in
- 44 wet days
- Avg wind
- 10 mph
- Travel score
- 2.6
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Eureka in Winter
Across winter, daytime highs hold fairly steady around 53°F.
A typical winter day in Eureka reaches about 53°F and drops to 47°F overnight. The warmest of the three months is December, the coolest January.
Eureka weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 53° / 46° | 8.0 | 15.3 | 9.4 | 2.6 |
| Feb | 53° / 46° | 6.7 | 13.4 | 10.4 | 2.6 |
| Mar | 53° / 47° | 7.0 | 14.7 | 11.7 | 2.6 |
| Apr | 53° / 48° | 4.1 | 11.8 | 13.1 | 3.0 |
| May | 55° / 50° | 2.1 | 7 | 14.2 | 3.9 |
| Jun | 57° / 52° | 0.9 | 3.7 | 14.9 | 4.9 |
| Jul | 60° / 53° | 0.1 | 0.8 | 14.6 | 6.0 |
| Aug | 61° / 54° | 0.2 | 0.9 | 13.6 | 6.3 |
| Sep | 61° / 54° | 0.6 | 2.3 | 12.3 | 6.3 |
| Oct | 59° / 52° | 2.9 | 6.3 | 10.9 | 5.1 |
| Nov | 55° / 49° | 5.7 | 12.5 | 9.7 | 3.3 |
| Dec | 53° / 47° | 9.6 | 15.6 | 9.1 | 2.6 |
Cloud cover in Winter
The sky is clear or mostly clear about 23% of the time across winter.
Chance of precipitation in Winter
Eureka gets around 24.3 in of rain over 44 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 10 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 18 min in early December to 10 h 54 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.1 kWh/m².
Hazard calendar for Eureka
In winter, Eureka overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Eureka's rainy season runs November–March, when most of the year's rain falls.
Is winter a good time to visit Eureka?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Eureka.
What to pack for Eureka in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Eureka sees daytime highs around 53°F and nights near 47°F. Pack a warm layer and rain gear. About 44 days see rain.
Sea temperature near Eureka in Winter
The nearest coast averages about 52°F across winter — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 55°F and coldest in March near 51°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 52 | 52 | 51 | 52 | 52 | 53 | 54 | 55 | 55 | 54 | 53 | 53 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 52 | Bracing |
| Feb | 52 | Bracing |
| Mar | 51 | Bracing |
| Apr | 52 | Bracing |
| May | 52 | Bracing |
| Jun | 53 | Bracing |
| Jul | 54 | Bracing |
| Aug | 55 | Bracing |
| Sep | 55 | Bracing |
| Oct | 54 | Bracing |
| Nov | 53 | Bracing |
| Dec | 53 | Bracing |
UV index in Eureka in Winter
Clear-sky midday UV across winter averages around 2. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Eureka peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 6 | 9 | 10 | 9 | 8 | 5 | 5 | 2 | 2 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 9 | Very high |
| Jun | 10 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 5 | High |
| Oct | 5 | Moderate |
| Nov | 2 | Low |
| Dec | 2 | Low |
Air quality in Eureka in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Eureka is worst in September — around 35 µg/m³ PM2.5 (poor), about 6.3× the cleanest month (December, 6 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 6 | 7 | 8 | 9 | 8 | 9 | 11 | 28 | 35 | 8 | 7 | 6 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Poor | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 6 | Good |
| Feb | 7 | Good |
| Mar | 8 | Good |
| Apr | 9 | Good |
| May | 8 | Good |
| Jun | 9 | Good |
| Jul | 11 | Good |
| Aug | 28 | Moderate |
| Sep | 35 | Poor |
| Oct | 8 | Good |
| Nov | 7 | Good |
| Dec | 6 | Good |
Where is Eureka?
Eureka sits at 40.8°N, 124.2°W, 39 ft above sea level, in United States. The nearest listed city is Bayside, 6.2 mi away.
Topography around Eureka
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Eureka.
Within 2 miles, the terrain around Eureka has only modest variations in elevation — a maximum elevation change of 302 ft around an average of 39 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,293 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,415 ft.
The land around Eureka is covered by water (35%) and artificial surfaces (32%) within 2 miles, water (46%) and trees (39%) within 10 miles, and trees (64%) and water (30%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Eureka (40.8021°, -124.1637°, elevation 39 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.