Eureka Air Quality Forecast - Today, Tomorrow
Air Quality Today
Today (10 October): Air quality in Eureka is fair. AQI and NO2 are fair; PM2.5, PM10, O3, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (NO2: 26.5/100).
Air Quality Tomorrow
Tomorrow (11 October 2026): Air quality in Eureka is fair. All pollutants stay as today. Pollution peaks around 3:00 PM (NO2: 23.4/100).
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Air Quality
Today - 10 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Fair | 26.5/100 |
| PM2.5 (fine particles) | Good | 4.8/100 |
| PM10 (coarse particles) | Good | 3.4/100 |
| NO2 (nitrogen dioxide) | Fair | 26.5/100 |
| O3 (ozone) | Good | 18.7/100 |
| SO2 (sulfur dioxide) | Good | 0.6/100 |
| CO (carbon monoxide) | Good | 0.4/100 |
| HCHO (formaldehyde) | Good | 2.4/100 |
| PM1 (ultrafine particles) | Good | 3.9/100 |
Tomorrow - 11 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Fair | 23.4/100 |
| PM2.5 (fine particles) | Good | 6.5/100 |
| PM10 (coarse particles) | Good | 4.9/100 |
| NO2 (nitrogen dioxide) | Fair | 23.4/100 |
| O3 (ozone) | Good | 18.1/100 |
| SO2 (sulfur dioxide) | Good | 0.8/100 |
| CO (carbon monoxide) | Good | 0.4/100 |
| HCHO (formaldehyde) | Good | 2.7/100 |
| PM1 (ultrafine particles) | Good | 4.9/100 |
Local Environmental Conditions
The center of Eureka is largely built up, so vehicle exhaust and urban activity dominate the local air pollution sources. Sea breezes along the coast usually help ventilate the area. On some days, pollution drifting in from farther away outweighs local sources. Levels are generally highest right next to busy roads and drop off quickly with distance.
Fine particle levels climb from February to April, as home heating and traffic combine with cold, still air averaging 10°C. Overall, stronger winds around May, about 20 km/h on average, usually bring some of the cleanest air of the year. Day to day, calm and dry conditions let pollution build, while wind and rain clear it away.
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Frequently Asked Questions About Air Quality in California
Is air quality bad in Eureka right now?
On 10 October 2026, overall air quality in Eureka is fair. AQI is the main air quality indicator at 26.5/100. Pollution peaks around 1:00 PM (NO2: 26.5/100).
Will air quality be worse tomorrow in Eureka?
On 11 October 2026, air quality conditions in Eureka will be similar to today, with AQI forecast at fair at 23.4/100. Pollution peaks around 3:00 PM (NO2: 23.4/100).
When is air pollution at its worst in Eureka?
Fine particle levels climb from February to April, as home heating and traffic combine with cold, still air averaging 10°C. Overall, stronger winds around May, about 20 km/h on average, usually bring some of the cleanest air of the year. Day to day, calm and dry conditions let pollution build, while wind and rain clear it away.
Are air quality levels in Eureka 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.
Understanding the Scale
The 0–100 air quality scores represent risk levels, not direct air pollutant concentrations. Higher scores indicate higher risk.
Air Quality
| Good | 0-20 | Low air quality risk. Air quality is expected to be good, with low levels of pollution. |
| Fair | 20-40 | Generally low air quality risk. Air quality is expected to be acceptable, with some pollution present. |
| Moderate | 40-60 | Moderate air quality risk. Air pollution is elevated and air quality may be less favorable. |
| Poor | 60-80 | High air quality risk. Air pollution is high and air quality is expected to be poor. |
| Very Poor | 80-100 | Very high air quality risk. Air pollution is very high and air quality is expected to be very poor. |