Worst air pollution Arcata, today and tomorrow
Today (9 August): Air quality in Arcata is fair. PM2.5 and O3 are fair; AQI, NO2, and PM1 are medium; PM10, SO2, CO, and HCHO are good. Pollution peaks around 10:00 PM (NO2: 59.3/100).
Tomorrow (10 August 2026): Air quality in Arcata is fair. PM2.5 decreases to medium; all other pollutants stay as today. Pollution peaks around 9:00 PM (NO2: 55.7/100). 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 - 9 August | Pollution peaks at 22:00
AQI:
Medium
59.3/100
PM2.5 (fine particles):
Fair
38.3/100
PM10 (coarse particles):
Good
11.6/100
NO2 (nitrogen dioxide):
Medium
59.3/100
O3 (ozone):
Fair
38.1/100
SO2 (sulfur dioxide):
Good
9.9/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
6.0/100
PM1 (ultrafine particles):
Medium
41.4/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 21:00
AQI:
Medium
55.7/100
PM2.5 (fine particles):
Medium
42.2/100
PM10 (coarse particles):
Good
17.4/100
NO2 (nitrogen dioxide):
Medium
55.7/100
O3 (ozone):
Fair
36.1/100
SO2 (sulfur dioxide):
Good
9.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
6.8/100
PM1 (ultrafine particles):
Medium
44.3/100
Pollen forecast in Arcata
View pollen forecastFrequently Asked Questions
Is air quality bad in Arcata right now?
On 9 August 2026, overall air quality in Arcata is fair. PM2.5 is the main pollutant at 38.3/100. Pollution peaks around 10:00 PM (NO2: 59.3/100).
Will air quality be worse tomorrow in Arcata?
On 10 August 2026, air quality conditions in Arcata will be similar to today, with O3 forecast at fair at 36.1/100. Pollution peaks around 9:00 PM (NO2: 55.7/100).
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.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 10 August 2026 at 02:34 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.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
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