Worst air pollution Arcata, today and tomorrow
Today (15 July): Air quality in Arcata is fair. PM2.5, PM10, and PM1 are fair; AQI, NO2, and O3 are medium; SO2, CO, and HCHO are good. Pollution peaks around 5:00 PM (NO2: 47.2/100).
Tomorrow (16 July 2026): Air quality in Arcata is fair. O3 increases to fair; PM1 decreases to good; all other pollutants stay as today. Pollution peaks around 10:00 PM (NO2: 45.2/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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In Arcata, cool, damp North Coast air is the main influence on air quality, and frequent marine fog keeps pollutant levels consistently low. Overall, Arcata sees air quality that tracks fairly closely with typical conditions for its wider region. As with most US destinations, conditions here are best understood by season rather than by a single yearly average.
Today - 15 July | Pollution peaks at 17:00
AQI:
Medium
47.2/100
PM2.5 (fine particles):
Fair
37.6/100
PM10 (coarse particles):
Fair
26.1/100
NO2 (nitrogen dioxide):
Medium
47.2/100
O3 (ozone):
Medium
44.1/100
SO2 (sulfur dioxide):
Good
14.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
7.6/100
PM1 (ultrafine particles):
Fair
24.4/100
Levels show the poorest local air quality during the day
Tomorrow - 16 July | Pollution peaks at 22:00
AQI:
Medium
45.2/100
PM2.5 (fine particles):
Fair
28.2/100
PM10 (coarse particles):
Fair
27.5/100
NO2 (nitrogen dioxide):
Medium
45.2/100
O3 (ozone):
Fair
37.6/100
SO2 (sulfur dioxide):
Good
10.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
5.6/100
PM1 (ultrafine particles):
Good
16.1/100
Pollen forecast in Arcata
View pollen forecastFrequently Asked Questions
Is air quality bad in Arcata right now?
On 15 July 2026, overall air quality in Arcata is fair. PM2.5 is the main pollutant at 37.6/100. Pollution peaks around 5:00 PM (NO2: 47.2/100).
Will air quality be worse tomorrow in Arcata?
On 16 July 2026, air quality conditions in Arcata will be similar to today, with O3 forecast at fair at 37.6/100. Pollution peaks around 10:00 PM (NO2: 45.2/100).
When is air pollution at its worst in Arcata?
Air quality in Arcata shifts across the year, as the shortest stretch of clean air usually falls in the wetter winter months; by contrast, summer sunshine and heat drive some of the worst ozone readings in the country. The mountains ringing the basin can trap pollution close to the ground for days when winds are calm.
Are air quality levels in Arcata based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Want to see air quality forecasts for other cities in United States?
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
For long term forecasts and maps, see the Airmine app