Brook Forest, Colorado Air Quality
Brook Forest has a median AQI of 51, earning an air quality grade of B — good air quality that ranks better than 11% of US cities. Air quality has been trending worse over the past decade, a concern for local residents and health officials. Ground-level ozone is the primary concern, typically peaking on warm sunny days due to vehicle and industrial emissions. In 2025, Brook Forest recorded 127 good air quality days (47% of monitored days) and 13 unhealthy days.
Population: 355 • County: Jefferson
Current AQI
Quick Facts
| Current AQI | 14 — Good |
| Air Quality Grade | B |
| Median AQI (2025) | 51 |
| vs. U.S. Cities | Better than 11% |
| Primary Pollutant | Ozone |
| Unhealthy Days/Year | 13 |
| 10-Year Trend | ↓ Worsening |
| Data Source | EPA AQS (historical) · AirNow (live) |
Health Recommendation
Air quality is satisfactory, and air pollution poses little or no risk.
It's a great day to be active outside!
5-Day AQI Forecast
Last 90 Days
Current Pollutant Levels
Real-time data from EPA AirNow
Local Air Quality Context
Air quality data for Brook Forest is sourced from the Chatfield Park - 11500 N. Roxborough Park Rd. monitoring area, located approximately 18 miles from city center. This EPA-certified station continuously tracks ground-level ozone, the primary driver of air quality alerts in this area.
Brook Forest typically sees its worst air quality during summer afternoons when heat and sunlight drive ground-level ozone formation from vehicle and industrial emissions. Morning readings are generally 15–25 points lower than afternoon peaks. Outdoor activity is best planned for early morning on high-ozone days.
AQI Trend (10 Years)
Air Quality Days by Year
Brook Forest Median AQI by Year
Annual EPA air quality data for Brook Forest — median AQI, day-category breakdown, and primary pollutant per year.
| Year | Median AQI | Good Days | Unhealthy Days | Max AQI | Primary Pollutant |
|---|---|---|---|---|---|
| 2025 | 51 | 127 | 13 | 119 | Ozone |
| 2024 | 50 | 192 | 37 | 174 | Ozone |
| 2023 | 49 | 206 | 18 | 143 | Ozone |
| 2022 | 47 | 234 | 31 | 166 | Ozone |
| 2021 | 47 | 222 | 55 | 172 | Ozone |
| 2020 | 46 | 231 | 27 | 161 | Ozone |
| 2019 | 46 | 238 | 16 | 129 | Ozone |
| 2018 | 46 | 229 | 37 | 151 | Ozone |
| 2017 | 47 | 214 | 28 | 136 | Ozone |
| 2016 | 46 | 245 | 20 | 159 | Ozone |
Source: EPA Air Quality System (AQS) annual summaries. "Unhealthy Days" includes Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous categories.
2025 Air Quality Summary
Primary Pollutant Days (2025)
Days when each pollutant was the primary driver of AQI. Learn about pollutants →
Frequently Asked Questions About Brook Forest Air Quality
What is the air quality in Brook Forest today?
The current AQI in Brook Forest is 14, rated "Good". Air quality is good — outdoor activity is safe for everyone today. Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in Brook Forest getting better or worse?
Air quality in Brook Forest has been worsening. The median AQI has risen 5 points (from 46 in 2016 to 51 in 2025), a concern for local health officials.
What is the most common air pollutant in Brook Forest?
Ozone is the primary air pollutant in Brook Forest, responsible for 273 days (100% of monitored days) in 2025. Ground-level ozone forms when sunlight reacts with emissions from vehicles and industry, typically peaking on hot summer afternoons.
How many unhealthy air days does Brook Forest have per year?
In 2025, Brook Forest recorded 47% good air quality days (127 days) out of 273 monitored days. There were 13 Unhealthy for Sensitive Groups days and 0 Unhealthy days (AQI above 100). The highest single-day AQI recorded was 119.
What air quality grade does Brook Forest receive?
Brook Forest receives an air quality grade of B, placing it better than 11% of US cities. This is based on a median AQI of 51 in 2025, with 127 good air quality days. The EPA monitors air quality in this area continuously using certified monitoring stations.
Air Quality Grade
Better than 11% of US cities
Nearby Cities
Protect Your Health
With a median AQI of 51, indoor air purification is recommended
See Recommended Purifiers ↓Get AQI Alerts
Receive notifications when air quality changes in Brook Forest
National Rankings
See how Brook Forest compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Brook Forest
Brook Forest has a summer ozone problem — hot afternoons push AQI into Moderate or higher as sunlight converts vehicle and industrial emissions into ground-level ozone. Activated carbon and PECO filters chemically neutralize ozone rather than just trapping particles.
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