Niles District, Fremont Air Quality Forecast - Today, Tomorrow
Air Quality Today
Today (10 October): Air quality in Niles District is fair. AQI, PM2.5, and O3 are fair; PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 2:00 AM (O3: 33.1/100).
Air Quality Tomorrow
Tomorrow (11 October 2026): Air quality in Niles District is moderate. AQI worsens to moderate; PM2.5 increases to moderate; all other pollutants stay as today. Pollution peaks around 3:00 PM (PM2.5: 40.4/100).
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Air Quality
Today - 10 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Fair | 33.1/100 |
| PM2.5 (fine particles) | Fair | 27.2/100 |
| PM10 (coarse particles) | Good | 13.0/100 |
| NO2 (nitrogen dioxide) | Good | 1.1/100 |
| O3 (ozone) | Fair | 33.1/100 |
| SO2 (sulfur dioxide) | Good | 0.5/100 |
| CO (carbon monoxide) | Good | 0.5/100 |
| HCHO (formaldehyde) | Good | 1.5/100 |
| PM1 (ultrafine particles) | Good | 3.9/100 |
Tomorrow - 11 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Moderate | 40.4/100 |
| PM2.5 (fine particles) | Moderate | 40.4/100 |
| PM10 (coarse particles) | Good | 19.9/100 |
| NO2 (nitrogen dioxide) | Good | 2.7/100 |
| O3 (ozone) | Fair | 33.8/100 |
| SO2 (sulfur dioxide) | Good | 0.8/100 |
| CO (carbon monoxide) | Good | 0.5/100 |
| HCHO (formaldehyde) | Good | 2.5/100 |
| PM1 (ultrafine particles) | Good | 7.3/100 |
Local Environmental Conditions
Around this part of Fremont, a mix of built-up land and open space means traffic is an important, but not overwhelming, local pollution source. Open grassland and scrub can produce smoke during grass fires and some dust in dry spells. Parks and street trees provide a modest buffer against traffic pollution. On some days, pollution drifting in from farther away outweighs local sources.
Cold spells from December to February, at around 9°C on average, are when smoke from home heating and traffic lingers longest. In August, strong sunshine and temperatures around 20°C drive ozone formation, with levels peaking in the afternoon. With little rain from April to September, dust from dry fields and open ground becomes more common. The risk of wildfire smoke peaks from June to October, when dry vegetation burns easily.
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Frequently Asked Questions About Air Quality in California
Is air quality bad in Niles District right now?
On 10 October 2026, overall air quality in Niles District is fair. AQI is the main air quality indicator at 33.1/100. Pollution peaks around 2:00 AM (O3: 33.1/100).
Will air quality be worse tomorrow in Niles District?
On 11 October 2026, air quality conditions in Niles District will be worse than today, with AQI forecast at moderate at 40.4/100. Pollution peaks around 3:00 PM (PM2.5: 40.4/100).
When is air pollution at its worst in Niles District?
Cold spells from December to February, at around 9°C on average, are when smoke from home heating and traffic lingers longest. In August, strong sunshine and temperatures around 20°C drive ozone formation, with levels peaking in the afternoon. With little rain from April to September, dust from dry fields and open ground becomes more common. The risk of wildfire smoke peaks from June to October, when dry vegetation burns easily.
Are air quality levels in Niles District 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. |