Arcata weather in October

In October, Arcata sees average daytime highs of 61°F and overnight lows near 48°F, with 3.2 in of rain across 6.4 wet days and about 10.9 hours of daylight. It is the 5th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 64°F in the first days to 58°F by the end. The sky is clear or mostly clear about 54% 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 Arcata's 5th-clearest and 10th-windiest month. For the whole year in context, see Arcata's year-round climate.

Daytime high
61°
5th warmest
Overnight low
48°
8th coldest
Rainfall
3.2 in
6.4 wet days
Daylight
10 h 54 min
6:35 AM – 5:28 PM
Cloud cover
41%
5th clearest
Wind
5 mph
10th windiest
Solar energy
3.77 kWh/m²
Travel score
5.9
out of 10

Arcata is city in Humboldt County, California, United States.

Density
627/km²
people per km²
Founded
1858

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 64°F in the first days to 58°F by the end.

A typical October day in Arcata reaches about 61°F in the afternoon and slips back to 48°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 55°F and 69°F. Set against its neighbours, October runs about 5°F cooler than September and about 7°F warmer than November.

30°40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
16450
26450
36450
46450
56449
66349
76349
86349
96349
106349
116249
126248
136248
146248
156248
166248
176148
186148
196147
206147
216147
226047
236047
246047
256047
265947
275946
285946
295846
305846
315846

Arcata weather by month

How October compares with the rest of the year at a glance. October is the 5th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan51° / 41°8.615.41.89.42.2
Feb52° / 41°7.113.12.410.42.4
Mar53° / 42°7.414.72.711.72.6
Apr55° / 44°4.411.8113.13.3
May58° / 47°2.47.20.114.24.7
Jun62° / 50°1.03.8014.96.3
Jul66° / 53°0.10.8014.68.0
Aug67° / 53°0.20.9013.68.1
Sep66° / 52°0.72.5012.37.7
Oct61° / 48°3.26.4010.95.9
Nov55° / 44°6.212.30.59.73.2
Dec50° / 40°10.115.41.79.12.1

Cloud cover in October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 54% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 14% of October, with mostly cloudy or overcast conditions the remaining 32%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17921
27921
37723
47723
57624
67525
77426
87426
97327
107228
117228
127129
137129
146931
156931
166832
176733
186634
196535
206436
216436
226337
236337
246238
256139
266139
276040
285941
295842
305743
315644

Chance of precipitation in October

Any precipitation

Arcata gets around 3.2 in of rain over 6.4 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 28% 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
1017
1117
1218
1318
1419
1519
1620
1721
1821
1922
2023
2123
2224
2324
2425
2525
2625
2726
2826
2927
3027
3128

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 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1973
2982
3982
4982
5982
6982
7991
8991
9991
10991
11991
12982
13982
14982
15982
16982
17982
18982
19982
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991
31991

Wind in October

Winds average 5 mph in October.

Across October, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

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 5:52 PM to 5:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:185:52
211.56:195:51
311.56:205:49
411.46:215:47
511.46:225:46
611.36:245:44
711.36:255:42
811.26:265:41
911.26:275:39
1011.26:285:37
1111.16:295:36
1211.16:305:34
1311.06:315:33
1411.06:325:31
1510.96:345:30
1610.96:355:28
1710.86:365:27
1810.86:375:25
1910.86:385:24
2010.76:395:22
2110.76:405:21
2210.66:425:19
2310.66:435:18
2410.56:445:17
2510.56:455:15
2610.56:465:14
2710.46:475:13
2810.46:495:11
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 3.77 kWh/m².

For context, solar energy here swings from a low near 1.65 kWh/m² to a high of 7.82 kWh/m² in July across the year — October's 3.77 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.7Bright
24.6Bright
34.6Bright
44.5Bright
54.5Bright
64.4Bright
74.3Bright
84.3Bright
94.2Bright
104.2Bright
114.1Bright
124.0Bright
134.0Moderate
143.9Moderate
153.9Moderate
163.8Moderate
173.7Moderate
183.7Moderate
193.6Moderate
203.5Moderate
213.5Moderate
223.4Moderate
233.4Moderate
243.3Moderate
253.3Moderate
263.2Moderate
273.1Moderate
283.1Moderate
293.0Moderate
303.0Moderate
312.9Moderate
Planning a trip in October

Hazard calendar for Arcata

In seasonPeak

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

Arcata'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 Arcata?

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

5.9
Sightseeing
5th-best month of the year
1.1
Beach & pool
5th-best month of the year

October is a reasonable time to visit Arcata for sightseeing.

What to pack for Arcata in October

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

In October, Arcata sees daytime highs around 61°F and nights near 48°F. Worth packing: a warm layer. About 6 days see rain.

a warm layer

Sea temperature near Arcata 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 Arcata 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 Arcata 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 Arcata 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 Arcata is worst in September — around 116 µg/m³ PM2.5 (unhealthy), about 23.7× the cleanest month (January, 5 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0306090120JanFebMarAprMayJunJulAugSepOctNovDecGoodUnhealthyGoodSep 12110 µg/m³Jan 15 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb7Good
Mar7Good
Apr7Good
May6Good
Jun6Good
Jul12Good
Aug85Unhealthy
Sep116Unhealthy
Oct16Moderate
Nov6Good
Dec5Good
Location & terrain

Where is Arcata?

Arcata sits at 40.9°N, 124.1°W, 23 ft above sea level, in United States. The nearest listed city is Bayside, 1.9 mi away.

Topography around Arcata

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Arcata.

Within 2 miles, the terrain around Arcata has significant variations in elevation — a maximum elevation change of 1,191 ft around an average of 157 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,690 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,415 ft.

The land around Arcata is covered by trees (40%) and grassland (29%) within 2 miles, trees (55%) and water (29%) within 10 miles, and trees (67%) and water (27%) within 50 miles.

2 miles
1,191 ft
10 miles
2,690 ft
50 miles
7,415 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
October weather nearby: Bayside 1.9 mi · McKinleyville 5.6 mi · Eureka 6.2 mi · Redding 91 mi · Grants Pass 116 mi · Ashland 116 mi · Medford 119 mi · Central Point 121 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 Arcata (40.8665°, -124.0828°, elevation 23 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).