Eureka weather in December

In December, Eureka sees average daytime highs of 53°F and overnight lows near 47°F, with 9.6 in of rain across 15.6 wet days and about 9.1 hours of daylight. It is the 9th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 53°F through the month. The sky is clear or mostly clear about 24% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 18 min at the start of December to 9 h 06 min by month's end. Set against the rest of the year, December is Eureka's 11th-clearest and 1st-windiest month. For the whole year in context, see Eureka's year-round climate.

Daytime high
53°
9th warmest
Overnight low
47°
4th coldest
Rainfall
9.6 in
15.6 wet days
Daylight
9 h 06 min
7:40 AM – 4:45 PM
Cloud cover
67%
11th clearest
Wind
10 mph
1st windiest
Solar energy
1.64 kWh/m²
Travel score
2.6
out of 10

Eureka is city in and county seat of Humboldt County, California, United States.

Density
722/km²
people per km²
Founded
1850

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 53°F through the month.

A typical December day in Eureka reaches about 53°F in the afternoon and slips back to 47°F overnight — a 6°F spread between the day's warmth and the night's chill. On most days the high lands between 48°F and 57°F. Set against its neighbours, December runs about 2°F cooler than November and on par with January.

40°45°50°55°60°151015202531
Avg high (°F)Avg low (°F)
15448
25348
35348
45347
55347
65347
75347
85347
95347
105347
115347
125347
135347
145347
155347
165347
175247
185246
195246
205246
215246
225246
235246
245246
255246
265246
275246
285246
295246
305246
315246

Eureka weather by month

How December compares with the rest of the year at a glance. December is the 9th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan53° / 46°8.015.39.42.6
Feb53° / 46°6.713.410.42.6
Mar53° / 47°7.014.711.72.6
Apr53° / 48°4.111.813.13.0
May55° / 50°2.1714.23.9
Jun57° / 52°0.93.714.94.9
Jul60° / 53°0.10.814.66.0
Aug61° / 54°0.20.913.66.3
Sep61° / 54°0.62.312.36.3
Oct59° / 52°2.96.310.95.1
Nov55° / 49°5.712.59.73.3
Dec53° / 47°9.615.69.12.6

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 11% of December, with mostly cloudy or overcast conditions the remaining 65%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23862
33763
43664
53664
63565
73466
83466
93367
103367
113367
123367
133268
143268
153268
163268
173367
183367
193367
203466
213565
223565
233664
243664
253763
263763
273763
283763
293664
303664
313565

Chance of precipitation in December

Any precipitation

Eureka gets around 9.6 in of rain over 15.6 wet days in December, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 50% and peaks near 52% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
147
248
348
449
549
650
751
851
951
1052
1152
1252
1352
1452
1552
1651
1751
1851
1950
2050
2149
2249
2349
2448
2548
2648
2748
2848
2948
3048
3149

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
11000
21000
31000
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991
311000

Wind in December

Winds average 10 mph in December, the windiest month of the year.

Across December, daily wind ranges from about 9 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
19light breeze
29light breeze
310light breeze
410light breeze
510light breeze
610light breeze
710light breeze
810light breeze
910light breeze
1010light breeze
1110light breeze
1210light breeze
1310light breeze
1410light breeze
1510light breeze
1610light breeze
1710light breeze
1810light breeze
1910light breeze
2010light breeze
2110light breeze
2210light breeze
2310light breeze
2410light breeze
2510light breeze
2610light breeze
2710light breeze
2810light breeze
2910light breeze
3010light breeze
3110light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 18 min at the start of December to 9 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:28 AM to 7:46 AM, and sunset from 4:45 PM to 4:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.37:284:45
29.37:294:45
39.37:304:45
49.27:314:45
59.27:324:44
69.27:324:44
79.27:334:44
89.27:344:44
99.27:354:44
109.17:364:44
119.17:374:44
129.17:374:45
139.17:384:45
149.17:394:45
159.17:404:45
169.17:404:45
179.17:414:46
189.17:414:46
199.17:424:46
209.17:434:47
219.17:434:47
229.17:444:48
239.17:444:48
249.17:444:49
259.17:454:49
269.17:454:50
279.17:464:50
289.17:464:51
299.17:464:52
309.17:464:52
319.17:464:53

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.64 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.64 kWh/m² to a high of 7.66 kWh/m² in July across the year — December's 1.64 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.7Dim
31.7Dim
41.7Dim
51.7Dim
61.7Dim
71.6Dim
81.6Dim
91.6Dim
101.6Dim
111.6Dim
121.6Dim
131.6Dim
141.6Dim
151.6Dim
161.6Dim
171.6Dim
181.6Dim
191.6Dim
201.6Dim
211.6Dim
221.6Dim
231.6Dim
241.6Dim
251.6Dim
261.6Dim
271.7Dim
281.7Dim
291.7Dim
301.7Dim
311.7Dim
Planning a trip in December

Hazard calendar for Eureka

In seasonPeak

In December, Eureka sits inside 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.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Eureka?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

2.6
Sightseeing
9th-best month of the year
Beach & pool
never really warm enough

December is a weaker month for outdoor sightseeing in Eureka.

What to pack for Eureka in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Eureka sees daytime highs around 53°F and nights near 47°F. Pack a warm layer and rain gear. About 16 days see rain.

a warm layerrain gear

Sea temperature near Eureka in December

The nearest coast averages about 53°F in December — 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.

50°52°54°56°JanFebMarAprMayJunJulAugSepOctNovDecbracing
Sea temperature (°F)Comfort
Jan52Bracing
Feb52Bracing
Mar51Bracing
Apr52Bracing
May52Bracing
Jun53Bracing
Jul54Bracing
Aug55Bracing
Sep55Bracing
Oct54Bracing
Nov53Bracing
Dec53Bracing

UV index in Eureka in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 21UV 9Dec 15UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May9Very high
Jun10Very high
Jul9Very high
Aug8Very high
Sep5High
Oct5Moderate
Nov2Low
Dec2Low

Air quality in Eureka in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December 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).

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1234 µg/m³Dec 186 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb7Good
Mar8Good
Apr9Good
May8Good
Jun9Good
Jul11Good
Aug28Moderate
Sep35Poor
Oct8Good
Nov7Good
Dec6Good
Location & terrain

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.

2 miles
302 ft
10 miles
2,293 ft
50 miles
7,415 ft
treesgrasslandartificial surfacesbare terrainwaterwetland
December weather nearby: Bayside 6.2 mi · Arcata 6.2 mi · McKinleyville 11 mi · Redding 94 mi · Grants Pass 121 mi · Ashland 122 mi · Medford 125 mi · Ukiah 125 mi

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
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).