Capitol Hill, Denver Air Quality Forecast - Today, Tomorrow
Air Quality Today
Today (10 October): Air quality in Capitol Hill is moderate. AQI and NO2 are moderate; PM2.5, O3, and PM1 are fair; PM10, SO2, CO, and HCHO are good. Pollution peaks around 8:00 PM (NO2: 48.5/100).
Air Quality Tomorrow
Tomorrow (11 October 2026): Air quality in Capitol Hill is moderate. All pollutants stay as today. Pollution peaks around 4:00 PM (NO2: 45.6/100).
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Air Quality
Today - 10 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Moderate | 48.5/100 |
| PM2.5 (fine particles) | Fair | 21.2/100 |
| PM10 (coarse particles) | Good | 10.9/100 |
| NO2 (nitrogen dioxide) | Moderate | 48.5/100 |
| O3 (ozone) | Fair | 36.4/100 |
| SO2 (sulfur dioxide) | Good | 1.6/100 |
| CO (carbon monoxide) | Good | 0.6/100 |
| HCHO (formaldehyde) | Good | 2.9/100 |
| PM1 (ultrafine particles) | Fair | 23.6/100 |
Tomorrow - 11 October
| Pollutant | Level | Value |
|---|---|---|
| AQI | Moderate | 45.6/100 |
| PM2.5 (fine particles) | Fair | 28.5/100 |
| PM10 (coarse particles) | Good | 15.7/100 |
| NO2 (nitrogen dioxide) | Moderate | 45.6/100 |
| O3 (ozone) | Fair | 37.6/100 |
| SO2 (sulfur dioxide) | Good | 1.7/100 |
| CO (carbon monoxide) | Good | 0.5/100 |
| HCHO (formaldehyde) | Good | 3.4/100 |
| PM1 (ultrafine particles) | Fair | 28.0/100 |
Local Environmental Conditions
With buildings covering much of the area around this location in Denver, traffic and other urban emissions are the biggest local influence on air quality. In cold weather, wood burning and other home heating become a noticeable source of fine particles. Pockets of trees and green space help filter a small share of the particles from traffic. Pollution carried in from the wider region can also raise levels at times.
Hot afternoons from July to August, averaging 23°C in the warmest month, are when ozone is most likely to build up. Cold spells from November to April, at around -1°C on average, are when smoke from home heating and traffic lingers longest. February is usually the windiest month, averaging about 15 km/h, which helps keep the air clean.
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Frequently Asked Questions About Air Quality in Colorado
Is air quality bad in Capitol Hill right now?
On 10 October 2026, overall air quality in Capitol Hill is moderate. AQI is the main air quality indicator at 48.5/100. Pollution peaks around 8:00 PM (NO2: 48.5/100).
Will air quality be worse tomorrow in Capitol Hill?
On 11 October 2026, air quality conditions in Capitol Hill will be similar to today, with AQI forecast at moderate at 45.6/100. Pollution peaks around 4:00 PM (NO2: 45.6/100).
When is air pollution at its worst in Capitol Hill?
Hot afternoons from July to August, averaging 23°C in the warmest month, are when ozone is most likely to build up. Cold spells from November to April, at around -1°C on average, are when smoke from home heating and traffic lingers longest. February is usually the windiest month, averaging about 15 km/h, which helps keep the air clean.
Are air quality levels in Capitol Hill 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. |