Worst air pollution Castle Rock, today and tomorrow
Today (16 July): Air quality in Castle Rock is fair. PM2.5 and O3 are fair; AQI and NO2 are medium; PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 11:00 PM (NO2: 43.9/100).
Tomorrow (17 July 2026): Air quality in Castle Rock is fair. All pollutants stay as today. Pollution peaks around 12:00 AM (NO2: 43.2/100). 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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Castle Rock's air quality reflects the Denver southern metropolitan Front Range position at 1,771 metres in Douglas County, with vehicle emissions from I-25 the primary local source in this rapidly growing suburban corridor. The Rocky Mountains provide clean westerly airflows on most days, while the Front Range temperature inversion problem periodically affects the southern corridor and summer wildfire smoke from Colorado forests is an increasingly frequent seasonal concern.
Today - 16 July | Pollution peaks at 23:00
AQI:
Medium
43.9/100
PM2.5 (fine particles):
Fair
23.5/100
PM10 (coarse particles):
Good
15.9/100
NO2 (nitrogen dioxide):
Medium
43.9/100
O3 (ozone):
Fair
35.2/100
SO2 (sulfur dioxide):
Good
10.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.5/100
PM1 (ultrafine particles):
Good
16.7/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 00:00
AQI:
Medium
43.2/100
PM2.5 (fine particles):
Fair
28.5/100
PM10 (coarse particles):
Good
19.5/100
NO2 (nitrogen dioxide):
Medium
43.2/100
O3 (ozone):
Fair
39.5/100
SO2 (sulfur dioxide):
Good
9.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.6/100
PM1 (ultrafine particles):
Good
19.1/100
Pollen forecast in Castle Rock
View pollen forecastFrequently Asked Questions
Is air quality bad in Castle Rock right now?
On 16 July 2026, overall air quality in Castle Rock is fair. O3 is the main pollutant at 35.2/100. Pollution peaks around 11:00 PM (NO2: 43.9/100).
Will air quality be worse tomorrow in Castle Rock?
On 17 July 2026, air quality conditions in Castle Rock will be similar to today, with O3 forecast at fair at 39.5/100. Pollution peaks around 12:00 AM (NO2: 43.2/100).
When is air pollution at its worst in Castle Rock?
Seasonal changes shape air quality across Castle Rock, as a brief window in autumn tends to bring the year's best air, before winter inversions set in; by contrast, summer brings regional wildfire smoke, while winter brings its own inversion-driven pollution episodes. Higher-elevation, more exposed locations generally avoid the worst of the valley inversion episodes.
Are air quality levels in Castle Rock 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.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.
For long term forecasts and maps, see the Airmine app