Arcata weather in September
In September, Arcata sees average daytime highs of 66°F and overnight lows near 52°F, with 0.7 in of rain across 2.5 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 10th-wettest month of the year here.
Day-to-day highs hold fairly steady near 66°F through the month. The sky is clear or mostly clear about 69% of the time in September, and the air most often feels dry.
Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Arcata's 2nd-clearest and 12th-windiest month. For the whole year in context, see Arcata's year-round climate.
- Daytime high
- 66°
- 3rd warmest
- Overnight low
- 52°
- 10th coldest
- Rainfall
- 0.7 in
- 2.5 wet days
- Daylight
- 12 h 18 min
- 6:03 AM – 6:19 PM
- Cloud cover
- 30%
- 2nd clearest
- Wind
- 5 mph
- 12th windiest
- Solar energy
- 5.56 kWh/m²
- Travel score
- 7.7
- 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 September
Day-to-day highs hold fairly steady near 66°F through the month.
A typical September day in Arcata reaches about 66°F in the afternoon and slips back to 52°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 60°F and 74°F. Set against its neighbours, September runs on par with August and about 5°F warmer than October.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 67 | 67 | 67 | 67 | 67 | 67 | 67 | 67 | 67 | 67 | 67 | 67 | 66 | 66 | 66 | 66 | 66 | 66 | 66 | 66 | 66 | 66 | 66 | 66 | 65 | 65 | 65 | 65 | 65 | 65 |
| Avg low (°F) | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 51 | 51 | 51 | 51 | 51 | 51 | 51 | 51 | 51 | 51 | 50 | 50 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 67 | 53 |
| 2 | 67 | 53 |
| 3 | 67 | 53 |
| 4 | 67 | 53 |
| 5 | 67 | 53 |
| 6 | 67 | 53 |
| 7 | 67 | 53 |
| 8 | 67 | 52 |
| 9 | 67 | 52 |
| 10 | 67 | 52 |
| 11 | 67 | 52 |
| 12 | 67 | 52 |
| 13 | 66 | 52 |
| 14 | 66 | 52 |
| 15 | 66 | 52 |
| 16 | 66 | 52 |
| 17 | 66 | 52 |
| 18 | 66 | 52 |
| 19 | 66 | 51 |
| 20 | 66 | 51 |
| 21 | 66 | 51 |
| 22 | 66 | 51 |
| 23 | 66 | 51 |
| 24 | 66 | 51 |
| 25 | 65 | 51 |
| 26 | 65 | 51 |
| 27 | 65 | 51 |
| 28 | 65 | 51 |
| 29 | 65 | 50 |
| 30 | 65 | 50 |
Arcata weather by month
How September compares with the rest of the year at a glance. September is the 3rd-warmest and 10th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 51° / 41° | 8.6 | 15.4 | 1.8 | 9.4 | 2.2 |
| Feb | 52° / 41° | 7.1 | 13.1 | 2.4 | 10.4 | 2.4 |
| Mar | 53° / 42° | 7.4 | 14.7 | 2.7 | 11.7 | 2.6 |
| Apr | 55° / 44° | 4.4 | 11.8 | 1 | 13.1 | 3.3 |
| May | 58° / 47° | 2.4 | 7.2 | 0.1 | 14.2 | 4.7 |
| Jun | 62° / 50° | 1.0 | 3.8 | 0 | 14.9 | 6.3 |
| Jul | 66° / 53° | 0.1 | 0.8 | 0 | 14.6 | 8.0 |
| Aug | 67° / 53° | 0.2 | 0.9 | 0 | 13.6 | 8.1 |
| Sep | 66° / 52° | 0.7 | 2.5 | 0 | 12.3 | 7.7 |
| Oct | 61° / 48° | 3.2 | 6.4 | 0 | 10.9 | 5.9 |
| Nov | 55° / 44° | 6.2 | 12.3 | 0.5 | 9.7 | 3.2 |
| Dec | 50° / 40° | 10.1 | 15.4 | 1.7 | 9.1 | 2.1 |
Cloud cover in September
The sky is clear or mostly clear about 69% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 17%. Skies tend to cloud over as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 89 | 89 | 89 | 88 | 88 | 87 | 87 | 86 | 85 | 84 | 84 | 83 | 82 | 82 | 82 | 82 | 82 | 81 | 81 | 81 | 81 | 81 | 81 | 81 | 81 | 81 | 81 | 80 | 79 | 79 |
| Cloudier (%) | 11 | 11 | 11 | 12 | 12 | 13 | 13 | 14 | 15 | 16 | 16 | 17 | 18 | 18 | 18 | 18 | 18 | 19 | 19 | 19 | 19 | 19 | 19 | 19 | 19 | 19 | 19 | 20 | 21 | 21 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 89 | 11 |
| 2 | 89 | 11 |
| 3 | 89 | 11 |
| 4 | 88 | 12 |
| 5 | 88 | 12 |
| 6 | 87 | 13 |
| 7 | 87 | 13 |
| 8 | 86 | 14 |
| 9 | 85 | 15 |
| 10 | 84 | 16 |
| 11 | 84 | 16 |
| 12 | 83 | 17 |
| 13 | 82 | 18 |
| 14 | 82 | 18 |
| 15 | 82 | 18 |
| 16 | 82 | 18 |
| 17 | 82 | 18 |
| 18 | 81 | 19 |
| 19 | 81 | 19 |
| 20 | 81 | 19 |
| 21 | 81 | 19 |
| 22 | 81 | 19 |
| 23 | 81 | 19 |
| 24 | 81 | 19 |
| 25 | 81 | 19 |
| 26 | 81 | 19 |
| 27 | 81 | 19 |
| 28 | 80 | 20 |
| 29 | 79 | 21 |
| 30 | 79 | 21 |
Chance of precipitation in September
Arcata gets around 0.7 in of rain over 2.5 wet days in September. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 9% and peaks near 13% on the wettest days. The odds climb toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 6 | 7 | 7 | 8 | 9 | 9 | 10 | 10 | 10 | 11 | 11 | 12 | 12 | 12 | 12 | 12 | 12 | 13 | 13 | 13 | 13 | 13 |
| Rain chance (%) | |
|---|---|
| 1 | 3 |
| 2 | 3 |
| 3 | 3 |
| 4 | 3 |
| 5 | 4 |
| 6 | 4 |
| 7 | 4 |
| 8 | 5 |
| 9 | 6 |
| 10 | 7 |
| 11 | 7 |
| 12 | 8 |
| 13 | 9 |
| 14 | 9 |
| 15 | 10 |
| 16 | 10 |
| 17 | 10 |
| 18 | 11 |
| 19 | 11 |
| 20 | 12 |
| 21 | 12 |
| 22 | 12 |
| 23 | 12 |
| 24 | 12 |
| 25 | 12 |
| 26 | 13 |
| 27 | 13 |
| 28 | 13 |
| 29 | 13 |
| 30 | 13 |
Humidity in September
Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the dry band about 92% of days. It rarely turns muggy — the humid and sticky bands barely register.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 86 | 87 | 87 | 88 | 89 | 89 | 90 | 90 | 91 | 91 | 92 | 92 | 92 | 92 | 92 | 93 | 93 | 93 | 93 | 93 | 94 | 94 | 94 | 94 | 95 | 95 | 95 | 96 | 96 | 97 |
| Comfortable (%) | 14 | 13 | 13 | 12 | 11 | 11 | 10 | 10 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 7 | 7 | 7 | 7 | 7 | 6 | 6 | 6 | 6 | 5 | 5 | 5 | 4 | 4 | 3 |
| Dry (%) | Comfortable (%) | |
|---|---|---|
| 1 | 86 | 14 |
| 2 | 87 | 13 |
| 3 | 87 | 13 |
| 4 | 88 | 12 |
| 5 | 89 | 11 |
| 6 | 89 | 11 |
| 7 | 90 | 10 |
| 8 | 90 | 10 |
| 9 | 91 | 9 |
| 10 | 91 | 9 |
| 11 | 92 | 8 |
| 12 | 92 | 8 |
| 13 | 92 | 8 |
| 14 | 92 | 8 |
| 15 | 92 | 8 |
| 16 | 93 | 7 |
| 17 | 93 | 7 |
| 18 | 93 | 7 |
| 19 | 93 | 7 |
| 20 | 93 | 7 |
| 21 | 94 | 6 |
| 22 | 94 | 6 |
| 23 | 94 | 6 |
| 24 | 94 | 6 |
| 25 | 95 | 5 |
| 26 | 95 | 5 |
| 27 | 95 | 5 |
| 28 | 96 | 4 |
| 29 | 96 | 4 |
| 30 | 97 | 3 |
Wind in September
Winds average 5 mph in September, the calmest month.
Across September, 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.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 5 | calm |
| 2 | 5 | calm |
| 3 | 5 | calm |
| 4 | 5 | calm |
| 5 | 5 | calm |
| 6 | 5 | calm |
| 7 | 5 | calm |
| 8 | 5 | calm |
| 9 | 5 | calm |
| 10 | 5 | calm |
| 11 | 5 | calm |
| 12 | 5 | calm |
| 13 | 5 | calm |
| 14 | 5 | calm |
| 15 | 5 | calm |
| 16 | 5 | calm |
| 17 | 5 | calm |
| 18 | 5 | calm |
| 19 | 5 | calm |
| 20 | 5 | calm |
| 21 | 5 | calm |
| 22 | 5 | calm |
| 23 | 5 | calm |
| 24 | 5 | calm |
| 25 | 5 | calm |
| 26 | 5 | calm |
| 27 | 5 | calm |
| 28 | 5 | calm |
| 29 | 5 | calm |
| 30 | 5 | calm |
Sunrise & sunset in September
Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 84 minutes over September. Sunrise moves from 5:47 AM to 6:17 AM, and sunset from 6:45 PM to 5:54 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 13.0 | 12.9 | 12.9 | 12.8 | 12.8 | 12.7 | 12.7 | 12.6 | 12.6 | 12.5 | 12.5 | 12.5 | 12.4 | 12.4 | 12.3 | 12.3 | 12.2 | 12.2 | 12.1 | 12.1 | 12.0 | 12.0 | 11.9 | 11.9 | 11.8 | 11.8 | 11.8 | 11.7 | 11.7 | 11.6 |
| Sunrise (AM) | 5:47 | 5:48 | 5:49 | 5:50 | 5:51 | 5:52 | 5:53 | 5:55 | 5:56 | 5:57 | 5:58 | 5:59 | 6:00 | 6:01 | 6:02 | 6:03 | 6:04 | 6:05 | 6:06 | 6:07 | 6:08 | 6:09 | 6:10 | 6:11 | 6:12 | 6:13 | 6:14 | 6:15 | 6:16 | 6:17 |
| Sunset (PM) | 6:45 | 6:43 | 6:41 | 6:40 | 6:38 | 6:36 | 6:34 | 6:33 | 6:31 | 6:29 | 6:27 | 6:26 | 6:24 | 6:22 | 6:20 | 6:19 | 6:17 | 6:15 | 6:13 | 6:12 | 6:10 | 6:08 | 6:06 | 6:05 | 6:03 | 6:01 | 5:59 | 5:58 | 5:56 | 5:54 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 13.0 | 5:47 | 6:45 |
| 2 | 12.9 | 5:48 | 6:43 |
| 3 | 12.9 | 5:49 | 6:41 |
| 4 | 12.8 | 5:50 | 6:40 |
| 5 | 12.8 | 5:51 | 6:38 |
| 6 | 12.7 | 5:52 | 6:36 |
| 7 | 12.7 | 5:53 | 6:34 |
| 8 | 12.6 | 5:55 | 6:33 |
| 9 | 12.6 | 5:56 | 6:31 |
| 10 | 12.5 | 5:57 | 6:29 |
| 11 | 12.5 | 5:58 | 6:27 |
| 12 | 12.5 | 5:59 | 6:26 |
| 13 | 12.4 | 6:00 | 6:24 |
| 14 | 12.4 | 6:01 | 6:22 |
| 15 | 12.3 | 6:02 | 6:20 |
| 16 | 12.3 | 6:03 | 6:19 |
| 17 | 12.2 | 6:04 | 6:17 |
| 18 | 12.2 | 6:05 | 6:15 |
| 19 | 12.1 | 6:06 | 6:13 |
| 20 | 12.1 | 6:07 | 6:12 |
| 21 | 12.0 | 6:08 | 6:10 |
| 22 | 12.0 | 6:09 | 6:08 |
| 23 | 11.9 | 6:10 | 6:06 |
| 24 | 11.9 | 6:11 | 6:05 |
| 25 | 11.8 | 6:12 | 6:03 |
| 26 | 11.8 | 6:13 | 6:01 |
| 27 | 11.8 | 6:14 | 5:59 |
| 28 | 11.7 | 6:15 | 5:58 |
| 29 | 11.7 | 6:16 | 5:56 |
| 30 | 11.6 | 6:17 | 5:54 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 5.56 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 — September's 5.56 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 6.3 | 6.3 | 6.2 | 6.2 | 6.1 | 6.1 | 6.0 | 5.9 | 5.9 | 5.8 | 5.8 | 5.7 | 5.7 | 5.6 | 5.5 | 5.5 | 5.4 | 5.4 | 5.3 | 5.3 | 5.2 | 5.2 | 5.1 | 5.1 | 5.0 | 5.0 | 4.9 | 4.9 | 4.8 | 4.7 |
| Level | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 6.3 | Intense |
| 2 | 6.3 | Intense |
| 3 | 6.2 | Intense |
| 4 | 6.2 | Intense |
| 5 | 6.1 | Intense |
| 6 | 6.1 | Intense |
| 7 | 6.0 | Intense |
| 8 | 5.9 | Bright |
| 9 | 5.9 | Bright |
| 10 | 5.8 | Bright |
| 11 | 5.8 | Bright |
| 12 | 5.7 | Bright |
| 13 | 5.7 | Bright |
| 14 | 5.6 | Bright |
| 15 | 5.5 | Bright |
| 16 | 5.5 | Bright |
| 17 | 5.4 | Bright |
| 18 | 5.4 | Bright |
| 19 | 5.3 | Bright |
| 20 | 5.3 | Bright |
| 21 | 5.2 | Bright |
| 22 | 5.2 | Bright |
| 23 | 5.1 | Bright |
| 24 | 5.1 | Bright |
| 25 | 5.0 | Bright |
| 26 | 5.0 | Bright |
| 27 | 4.9 | Bright |
| 28 | 4.9 | Bright |
| 29 | 4.8 | Bright |
| 30 | 4.7 | Bright |
Hazard calendar for Arcata
None of Arcata's seasonal hazards are active in September. 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.
Is September a good time to visit Arcata?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is one of the better times to visit Arcata for general sightseeing.
What to pack for Arcata in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Arcata sees daytime highs around 66°F and nights near 52°F. Worth packing: sun protection.
Sea temperature near Arcata in September
The nearest coast averages about 55°F in September — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 52 | 52 | 51 | 52 | 52 | 53 | 54 | 55 | 55 | 54 | 53 | 53 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 52 | Bracing |
| Feb | 52 | Bracing |
| Mar | 51 | Bracing |
| Apr | 52 | Bracing |
| May | 52 | Bracing |
| Jun | 53 | Bracing |
| Jul | 54 | Bracing |
| Aug | 55 | Bracing |
| Sep | 55 | Bracing |
| Oct | 54 | Bracing |
| Nov | 53 | Bracing |
| Dec | 53 | Bracing |
UV index in Arcata in September
Clear-sky midday UV in September 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 6 | 9 | 10 | 9 | 8 | 5 | 5 | 2 | 2 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 9 | Very high |
| Jun | 10 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 5 | High |
| Oct | 5 | Moderate |
| Nov | 2 | Low |
| Dec | 2 | Low |
Air quality in Arcata in September
Average fine-particle pollution (PM2.5) through the year — so you can see where September 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 5 | 7 | 7 | 7 | 6 | 6 | 12 | 85 | 116 | 16 | 6 | 5 |
| Level | Good | Good | Good | Good | Good | Good | Good | Unhealthy | Unhealthy | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 5 | Good |
| Feb | 7 | Good |
| Mar | 7 | Good |
| Apr | 7 | Good |
| May | 6 | Good |
| Jun | 6 | Good |
| Jul | 12 | Good |
| Aug | 85 | Unhealthy |
| Sep | 116 | Unhealthy |
| Oct | 16 | Moderate |
| Nov | 6 | Good |
| Dec | 5 | Good |
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.
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
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).