Littleton, Colorado Air Quality
Littleton 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, Littleton recorded 129 good air quality days (47% of monitored days) and 2 unhealthy days.
Population: 44,710 • County: Arapahoe
Loading AQI…
Quick Facts
| Current AQI | 8 — 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 AirNow |
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 30 Days
Current Pollutant Levels
Real-time data from EPA AirNow
AQI Trend (10 Years)
Air Quality Days by Year
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 Littleton Air Quality
What is the air quality in Littleton today?
The current AQI in Littleton is 8, which is rated "Good". Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in Littleton getting better or worse?
Air quality in Littleton has been worsening in recent years. The median AQI rose from 44 in 2016 to 51 in 2025.
What is the most common air pollutant in Littleton?
Ozone is the primary air pollutant in Littleton, responsible for the most air quality-impacted days in 2025. Ground-level ozone forms when sunlight reacts with vehicle and industrial emissions on warm days.
How many unhealthy air days does Littleton have per year?
In 2025, Littleton had 2 days when air quality was unhealthy or unhealthy for sensitive groups (AQI above 100). There were 129 good days and 142 moderate days out of 273 days monitored.
What air quality grade does Littleton receive?
Littleton receives an air quality grade of B, placing it better than 11% of US cities. This grade is based on a median AQI of 51 for 2025, derived from EPA monitoring data.
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 Littleton
National Rankings
See how Littleton compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Littleton
Based on your area's air quality (median AQI: 51), we recommend these air purifiers to help protect your health indoors.
Honeywell HPA300
Powerful workhorse for large rooms. Built to last.
- ✓Perfect room size match
- ✓Recommended for your air quality
- ✓Has 1/1 desired features
We may earn a commission from purchases
Other Great Options
Blueair Blue Pure 211+
High performance for large rooms with simple operation.
RabbitAir MinusA2
Stylish wall-mountable design with customizable artwork panels.
Molekule Air Pro
Commercial-grade with patented PECO technology for destroying pollutants.
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 →