Eureka weather in October

In October, Eureka sees average daytime highs of 59°F and overnight lows near 52°F, with 2.9 in of rain across 6.3 wet days and about 10.9 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 60°F in the first days to 57°F by the end. The sky is clear or mostly clear about 49% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 36 min at the start of October to 10 h 18 min by month's end. Set against the rest of the year, October is Eureka's 4th-clearest and 11th-windiest month. For the whole year in context, see Eureka's year-round climate.

Daytime high
59°
4th warmest
Overnight low
52°
9th coldest
Rainfall
2.9 in
6.3 wet days
Daylight
10 h 54 min
6:35 AM – 5:28 PM
Cloud cover
44%
4th clearest
Wind
8 mph
11th windiest
Solar energy
3.7 kWh/m²
Travel score
5.1
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 October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 60°F in the first days to 57°F by the end.

A typical October day in Eureka reaches about 59°F in the afternoon and slips back to 52°F overnight — a 7°F spread between the day's warmth and the night's chill. On most days the high lands between 54°F and 64°F. Set against its neighbours, October runs about 2°F cooler than September and about 4°F warmer than November.

40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
16053
26053
36053
46053
56053
66053
76053
86053
96053
105953
115952
125952
135952
145952
155952
165952
175952
185952
195852
205852
215851
225851
235851
245851
255851
265851
275751
285751
295751
305751
315751

Eureka weather by month

How October compares with the rest of the year at a glance. October is the 4th-warmest and 7th-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 October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 15% of October, with mostly cloudy or overcast conditions the remaining 35%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17228
27228
37228
47129
57129
67030
77030
86931
96931
106832
116832
126832
136733
146733
156634
166535
176535
186436
196337
206337
216238
226139
236139
246040
255941
265941
275842
285743
295743
305644
315545

Chance of precipitation in October

Any precipitation

Eureka gets around 2.9 in of rain over 6.3 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 20% and peaks near 29% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)
113
214
314
414
515
615
715
816
916
1016
1116
1217
1317
1418
1518
1619
1719
1820
1921
2022
2122
2223
2324
2424
2525
2625
2726
2826
2927
3028
3129

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, October lands in the dry band about 93% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
18614
28713
38713
48812
58911
68911
79010
89010
9919
10919
11919
12928
13928
14928
15928
16937
17937
18937
19946
20946
21955
22955
23964
24964
25964
26973
27973
28973
29973
30973
31973

Wind in October

Winds average 8 mph in October.

Across October, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137light breeze
147light breeze
157light breeze
167light breeze
177light breeze
187light breeze
197light breeze
207light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 36 min at the start of October to 10 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over October. Sunrise moves from 6:18 AM to 6:52 AM, and sunset from 5:53 PM to 5:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:185:53
211.56:205:51
311.56:215:49
411.46:225:48
511.46:235:46
611.36:245:44
711.36:255:43
811.36:265:41
911.26:275:39
1011.26:285:38
1111.16:295:36
1211.16:305:35
1311.06:325:33
1411.06:335:32
1510.96:345:30
1610.96:355:28
1710.86:365:27
1810.86:375:25
1910.86:385:24
2010.76:395:23
2110.76:415:21
2210.66:425:20
2310.66:435:18
2410.56:445:17
2510.56:455:16
2610.56:465:14
2710.46:485:13
2810.46:495:12
2910.36:505:10
3010.36:515:09
3110.36:525:08

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 3.7 kWh/m².

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 — October's 3.7 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.5Bright
34.5Bright
44.4Bright
54.4Bright
64.3Bright
74.2Bright
84.2Bright
94.1Bright
104.1Bright
114.0Bright
124.0Moderate
133.9Moderate
143.8Moderate
153.8Moderate
163.7Moderate
173.6Moderate
183.6Moderate
193.5Moderate
203.5Moderate
213.4Moderate
223.4Moderate
233.3Moderate
243.3Moderate
253.2Moderate
263.1Moderate
273.1Moderate
283.0Moderate
293.0Moderate
302.9Moderate
312.9Moderate
Planning a trip in October

Hazard calendar for Eureka

In seasonPeak

None of Eureka's seasonal hazards are active in October. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

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 October a good time to visit Eureka?

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

5.1
Sightseeing
4th-best month of the year
Beach & pool
never really warm enough

October is a reasonable time to visit Eureka for sightseeing.

What to pack for Eureka in October

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

In October, Eureka sees daytime highs around 59°F and nights near 52°F. Worth packing: a warm layer. About 6 days see rain.

a warm layer

Sea temperature near Eureka in October

The nearest coast averages about 54°F in October — 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 October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 5 — enough to warrant sun protection. 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 October

GoodModeratePoorUnhealthyVery unhealthy

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