Niles Canyon Transcontinental Railroad Historic District, Fremont Air Quality Forecast - Today, Tomorrow
Air Quality Today
Today (10 October): Air quality in Niles Canyon Transcontinental Railroad Historic 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: 30.9/100).
Air Quality Tomorrow
Tomorrow (11 October 2026): Air quality in Niles Canyon Transcontinental Railroad Historic District is fair. All pollutants stay as today. Pollution peaks around 3:00 PM (PM2.5: 34.8/100).
Explore Forecasts
Pollen
Air Quality for Neighborhoods
Get More in Our App
Local pollen and air quality forecasts, interactive pollen maps and route profiles
Features and forecast availability vary by region.
Air Quality
Today - 10 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Fair | 30.9/100 |
| PM2.5 (fine particles) | Fair | 22.8/100 |
| PM10 (coarse particles) | Good | 13.0/100 |
| NO2 (nitrogen dioxide) | Good | 1.6/100 |
| O3 (ozone) | Fair | 30.9/100 |
| 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 | Fair | 34.8/100 |
| PM2.5 (fine particles) | Fair | 34.8/100 |
| PM10 (coarse particles) | Good | 19.9/100 |
| NO2 (nitrogen dioxide) | Good | 3.8/100 |
| O3 (ozone) | Fair | 31.6/100 |
| 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
With little dense development around this location in Fremont, local traffic emissions are modest. The open grass and scrubland around the area can add dust in dry weather and smoke from occasional fires. The surrounding woodland releases natural compounds that, in warm sunny weather, help form ozone. On some days, pollution drifting in from farther away outweighs local sources.
Fine particle levels climb from December to February, as wood burning and traffic combine with cold, still air averaging 9°C. In August, strong sunshine and temperatures around 20°C drive ozone formation, with levels peaking in the afternoon. From June to October, dry weather raises the risk of wildfires, and their smoke can cover the area in haze.
Get pollen & AQ on Strava
Follow your environmental exposure and performance with the free Airmine-Strava integration. See your pollen and air quality exposure for every Strava activity.
Resource Hub
Frequently Asked Questions About Air Quality in California
Is air quality bad in Niles Canyon Transcontinental Railroad Historic District right now?
On 10 October 2026, overall air quality in Niles Canyon Transcontinental Railroad Historic District is fair. AQI is the main air quality indicator at 30.9/100. Pollution peaks around 2:00 AM (O3: 30.9/100).
Will air quality be worse tomorrow in Niles Canyon Transcontinental Railroad Historic District?
On 11 October 2026, air quality conditions in Niles Canyon Transcontinental Railroad Historic District will be similar to today, with AQI forecast at fair at 34.8/100. Pollution peaks around 3:00 PM (PM2.5: 34.8/100).
When is air pollution at its worst in Niles Canyon Transcontinental Railroad Historic District?
Fine particle levels climb from December to February, as wood burning and traffic combine with cold, still air averaging 9°C. In August, strong sunshine and temperatures around 20°C drive ozone formation, with levels peaking in the afternoon. From June to October, dry weather raises the risk of wildfires, and their smoke can cover the area in haze.
Are air quality levels in Niles Canyon Transcontinental Railroad Historic 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. |