Arcata weather in January

In January, Arcata sees average daytime highs of 51°F and overnight lows near 41°F, with 8.6 in of precipitation across 15.4 wet days and about 9.4 hours of daylight. It is the 11th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 51°F through the month. The sky is clear or mostly clear about 23% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 06 min at the start of January to 9 h 48 min by month's end. Set against the rest of the year, January is Arcata's 12th-clearest and 4th-windiest month. For the whole year in context, see Arcata's year-round climate.

Daytime high
51°
11th warmest
Overnight low
41°
2nd coldest
Precipitation
8.6 in
15.4 wet days
Daylight
9 h 24 min
7:44 AM – 5:07 PM
Cloud cover
68%
12th clearest
Wind
7 mph
4th windiest
Solar energy
1.86 kWh/m²
Travel score
2.2
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 January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 51°F through the month.

A typical January day in Arcata reaches about 51°F in the afternoon and slips back to 41°F overnight — a 10°F spread between the day's warmth and the night's chill. On most days the high lands between 45°F and 57°F. Set against its neighbours, January runs on par with December and on par with February.

30°40°50°60°151015202531
Avg high (°F)Avg low (°F)
15040
25040
35040
45040
55040
65040
75040
85040
95040
105140
115141
125141
135141
145141
155141
165141
175141
185141
195141
205141
215141
225141
235141
245141
255141
265241
275241
285241
295241
305241
315241

Arcata weather by month

How January compares with the rest of the year at a glance. January is the 11th-warmest and 2nd-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 January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 10% of January, with mostly cloudy or overcast conditions the remaining 67%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13565
23565
33466
43367
53367
63367
73268
83268
93169
103367
113268
123367
133268
143367
153268
163367
173367
183367
193367
203367
213466
223367
233367
243367
253367
263268
273466
283466
293367
303367
313367

Chance of precipitation in January

Any precipitationSnow

Arcata gets around 8.6 in of rain and snow over 15.4 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 50% and peaks near 51% on the wettest days, and about 2 days bring snow.

0%20%40%60%151015202531
Rain chance (%)Snow chance (%)
1498
2498
3507
4507
5507
6506
7516
8515
9515
10515
11514
12514
13514
14514
15514
16514
17504
18504
19504
20505
21505
22505
23496
24496
25496
26486
27486
28476
29476
30465
31455

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in January

Winds average 7 mph in January.

Across January, daily wind ranges from about 7 mph on the calmest days to 7 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
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 9 h 06 min at the start of January to 9 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over January. Sunrise moves from 7:46 AM to 7:35 AM, and sunset from 4:53 PM to 5:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.17:464:53
29.17:464:54
39.17:464:54
49.17:464:55
59.27:464:56
69.27:464:57
79.27:464:58
89.27:464:59
99.27:465:00
109.27:465:01
119.37:465:02
129.37:465:03
139.37:455:04
149.37:455:05
159.37:455:06
169.47:445:07
179.47:445:08
189.47:445:09
199.47:435:10
209.57:435:11
219.57:425:12
229.57:425:13
239.67:415:15
249.67:415:16
259.67:405:17
269.67:395:18
279.77:385:19
289.77:385:20
299.77:375:22
309.87:365:23
319.87:355:24

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.86 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 — January's 1.86 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
11.7Dim
21.7Dim
31.7Dim
41.7Dim
51.7Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.8Dim
121.8Dim
131.8Dim
141.8Dim
151.8Dim
161.8Dim
171.9Dim
181.9Dim
191.9Dim
201.9Dim
212.0Dim
222.0Dim
232.0Moderate
242.0Moderate
252.1Moderate
262.1Moderate
272.1Moderate
282.2Moderate
292.2Moderate
302.3Moderate
312.3Moderate
Planning a trip in January

Hazard calendar for Arcata

In seasonPeak

In January, Arcata sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

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 January a good time to visit Arcata?

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

2.2
Sightseeing
11th-best month of the year
0.0
Beach & pool
8th-best month of the year

January is a weaker month for outdoor sightseeing in Arcata.

What to pack for Arcata in January

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

In January, Arcata sees daytime highs around 51°F and nights near 41°F. Pack a warm layer and rain gear. About 15 days see rain.

a warm layerrain gear

Sea temperature near Arcata in January

The nearest coast averages about 52°F in January — 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 January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 2. 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 January

GoodModeratePoorUnhealthyVery unhealthy

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