Arcata weather in August

In August, Arcata sees average daytime highs of 67°F and overnight lows near 53°F, with 0.2 in of rain across 0.9 wet days and about 13.6 hours of daylight. It is the 1st-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 67°F through the month. The sky is clear or mostly clear about 72% of the time in August, and the air most often feels dry.

Daylight stretches from about 14 h 12 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Arcata's 3rd-clearest and 11th-windiest month. For the whole year in context, see Arcata's year-round climate.

Daytime high
67°
1st warmest
Overnight low
53°
12th coldest
Rainfall
0.2 in
0.9 wet days
Daylight
13 h 36 min
5:31 AM – 7:10 PM
Cloud cover
30%
3rd clearest
Wind
5 mph
11th windiest
Solar energy
6.92 kWh/m²
Travel score
8.1
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 August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 67°F through the month.

A typical August day in Arcata reaches about 67°F in the afternoon and slips back to 53°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 73°F. Set against its neighbours, August runs on par with July and on par with September.

40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
16754
26754
36754
46754
56754
66754
76754
86754
96754
106754
116754
126754
136754
146754
156754
166754
176754
186754
196753
206753
216753
226753
236753
246753
256753
266753
276753
286753
296753
306753
316753

Arcata weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 11th-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 August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 72% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 17% of August, with mostly cloudy or overcast conditions the remaining 11%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
19010
29010
38911
48911
58911
68911
78911
88911
98911
108911
118911
128911
138911
148911
158911
168911
178911
188911
198911
208812
218812
228812
238812
248812
258812
268911
278911
288911
298911
308911
318911

Chance of precipitation in August

Any precipitation

Arcata gets around 0.2 in of rain over 0.9 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 3% and peaks near 4% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
11
22
32
42
52
62
72
82
92
102
112
122
132
142
153
163
173
183
194
204
214
224
234
244
254
264
274
284
294
304
313

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the dry band about 84% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
18614
28614
38614
48614
58614
68614
78614
88515
98515
108416
118416
128317
138317
148218
158218
168218
178119
188119
198119
208119
218119
228119
238119
248218
258218
268317
278317
288416
298515
308515
318614

Wind in August

Winds average 5 mph in August.

Across August, daily wind ranges from about 5 mph on the calmest days to 5 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
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 12 min at the start of August to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over August. Sunrise moves from 5:16 AM to 5:46 AM, and sunset from 7:29 PM to 6:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.25:167:29
214.25:177:28
314.15:187:26
414.15:197:25
514.15:207:24
614.05:217:23
714.05:227:22
814.05:237:20
913.95:247:19
1013.95:257:18
1113.85:267:17
1213.85:277:15
1313.85:287:14
1413.75:297:13
1513.75:307:11
1613.65:317:10
1713.65:327:08
1813.65:337:07
1913.55:347:05
2013.55:357:04
2113.45:367:02
2213.45:377:01
2313.45:386:59
2413.35:396:58
2513.35:406:56
2613.25:416:55
2713.25:426:53
2813.15:436:51
2913.15:446:50
3013.05:456:48
3113.05:466:46

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 6.92 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 — August's 6.92 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.4Intense
27.4Intense
37.4Intense
47.3Intense
57.3Intense
67.3Intense
77.2Intense
87.2Intense
97.2Intense
107.2Intense
117.1Intense
127.1Intense
137.0Intense
147.0Intense
157.0Intense
167.0Intense
176.9Intense
186.9Intense
196.8Intense
206.8Intense
216.8Intense
226.7Intense
236.7Intense
246.7Intense
256.6Intense
266.6Intense
276.5Intense
286.5Intense
296.5Intense
306.4Intense
316.4Intense
Planning a trip in August

Hazard calendar for Arcata

In seasonPeak

None of Arcata's seasonal hazards are active in August. 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 August a good time to visit Arcata?

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

8.1
Sightseeing
1st-best month of the year
4.0
Beach & pool
1st-best month of the year

August is one of the better times to visit Arcata for general sightseeing.

What to pack for Arcata in August

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

In August, Arcata sees daytime highs around 67°F and nights near 53°F. Pack sun protection.

sun protection

Sea temperature near Arcata in August

The nearest coast averages about 55°F in August — 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 August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 (very high — sun protection essential). 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 August

GoodModeratePoorUnhealthyVery unhealthy

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