Lake Forest, California Air Quality
Lake Forest has a median AQI of 52, earning an air quality grade of B — good air quality that ranks better than 10% of US cities. Air quality has been improving steadily over the past decade, a positive sign for residents. Particulate matter (PM2.5) is the primary concern, often linked to vehicle traffic, industrial activity, and wildfire smoke. In 2025, Lake Forest recorded 122 good air quality days (45% of monitored days) and 9 unhealthy days.
Population: 86,281 • County: Orange
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Quick Facts
| Current AQI | 15 — Good |
| Air Quality Grade | B |
| Median AQI (2025) | 52 |
| vs. U.S. Cities | Better than 10% |
| Primary Pollutant | PM2.5 |
| Unhealthy Days/Year | 9 |
| 10-Year Trend | ↑ Improving |
| 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 Lake Forest Air Quality
What is the air quality in Lake Forest today?
The current AQI in Lake Forest is 15, which is rated "Good". Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in Lake Forest getting better or worse?
Air quality in Lake Forest has been improving over the past decade. The median AQI dropped from 58 in 2016 to 52 in 2025.
What is the most common air pollutant in Lake Forest?
PM2.5 is the primary air pollutant in Lake Forest, responsible for the most air quality-impacted days in 2025. Particulate matter can originate from vehicle exhaust, wildfires, and industrial emissions.
How many unhealthy air days does Lake Forest have per year?
In 2025, Lake Forest had 9 days when air quality was unhealthy or unhealthy for sensitive groups (AQI above 100). There were 122 good days and 143 moderate days out of 274 days monitored.
What air quality grade does Lake Forest receive?
Lake Forest receives an air quality grade of B, placing it better than 10% of US cities. This grade is based on a median AQI of 52 for 2025, derived from EPA monitoring data.
Air Quality Grade
Better than 10% of US cities
Nearby Cities
Protect Your Health
With a median AQI of 52, indoor air purification is recommended
See Recommended Purifiers ↓Get AQI Alerts
Receive notifications when air quality changes in Lake Forest
National Rankings
See how Lake Forest compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Lake Forest
Based on your area's air quality (median AQI: 52), 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
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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 →