Holly Hills, Colorado Air Quality
Holly Hills 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, Holly Hills recorded 129 good air quality days (47% of monitored days) and 2 unhealthy days.
Population: 2,572 • County: Arapahoe
Current AQI
Quick Facts
| Current AQI | 10 — Good |
| Air Quality Grade | B |
| Median AQI (2025) | 51 |
| vs. U.S. Cities | Better than 11% |
| Primary Pollutant | Ozone |
| Unhealthy Days/Year | 2 |
| 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 Holly Hills is sourced from the Denver - NJH - 14th Ave. & Albion St. monitoring area, located approximately 5 miles from city center. This EPA-certified station continuously tracks ground-level ozone, the primary driver of air quality alerts in this area.
Holly Hills 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
Holly Hills Median AQI by Year
Annual EPA air quality data for Holly Hills — median AQI, day-category breakdown, and primary pollutant per year.
| Year | Median AQI | Good Days | Unhealthy Days | Max AQI | Primary Pollutant |
|---|---|---|---|---|---|
| 2025 | 51 | 129 | 2 | 101 | Ozone |
| 2024 | 49 | 196 | 17 | 161 | Ozone |
| 2023 | 47 | 239 | 8 | 136 | Ozone |
| 2022 | 46 | 237 | 12 | 129 | Ozone |
| 2021 | 46 | 220 | 37 | 161 | Ozone |
| 2020 | 46 | 243 | 11 | 159 | Ozone |
| 2019 | 47 | 222 | 6 | 140 | Ozone |
| 2018 | 46 | 227 | 15 | 156 | Ozone |
| 2017 | 47 | 221 | 7 | 119 | Ozone |
| 2016 | 44 | 261 | 6 | 119 | 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 Holly Hills Air Quality
What is the air quality in Holly Hills today?
The current AQI in Holly Hills is 10, 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 Holly Hills getting better or worse?
Air quality in Holly Hills has been worsening. The median AQI has risen 7 points (from 44 in 2016 to 51 in 2025), a concern for local health officials.
What is the most common air pollutant in Holly Hills?
Ozone is the primary air pollutant in Holly Hills, responsible for 240 days (88% 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 Holly Hills have per year?
In 2025, Holly Hills recorded 47% good air quality days (129 days) out of 273 monitored days. There were 2 Unhealthy for Sensitive Groups days and 0 Unhealthy days (AQI above 100). The highest single-day AQI recorded was 101.
What air quality grade does Holly Hills receive?
Holly Hills 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 129 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 Holly Hills
National Rankings
See how Holly Hills compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Holly Hills
Holly Hills 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.
Blueair Blue Pure 211+
High performance for large rooms with simple operation.
- ✓Good room size match
- ✓Recommended for your air quality
- ✓High performance
We may earn a commission from purchases
Other Great Options
Honeywell HPA300
Powerful workhorse for large rooms. Built to last.
Molekule Air Pro
Commercial-grade with patented PECO technology for destroying pollutants.
RabbitAir MinusA2
Stylish wall-mountable design with customizable artwork panels.
Not sure which air purifier is right for you?
Learn more about different types of air purifiers and how to choose the best one for your needs.
Read our complete buying guide →