Monterey, California Air Quality
Monterey County, California (CA)
→ Stableover 10 years
10-Year AQI Trend
The solid line shows the median AQI each year. The dashed line shows the 90th percentile (worst 10% of days).
Air Quality Day Breakdown
Number of days per year in each EPA AQI category. Green = Good (AQI 0-50), Yellow = Moderate (51-100), Orange = Unhealthy for Sensitive Groups (101-150), Red = Unhealthy or worse (151+).
Year-by-Year Data
| Year | Median AQI | 90th Pct | Max AQI | Good Days | Moderate | Unhealthy+ | Pollutant |
|---|---|---|---|---|---|---|---|
| 2023 | 42 | 55 | 115 | 274 | 90 | 1 | PM2.5 |
| 2022 | 39 | 54 | 80 | 299 | 66 | 0 | Ozone |
| 2021 | 41 | 57 | 80 | 261 | 104 | 0 | PM2.5 |
| 2020 | 39 | 64 | 275 | 259 | 92 | 15 | Ozone |
| 2019 | 39 | 54 | 144 | 303 | 61 | 1 | Ozone |
| 2018 | 42 | 57 | 157 | 258 | 100 | 7 | PM2.5 |
| 2017 | 41 | 58 | 121 | 265 | 99 | 1 | Ozone |
| 2016 | 37 | 55 | 185 | 290 | 65 | 11 | Ozone |
| 2015 | 41 | 54 | 120 | 285 | 79 | 1 | PM2.5 |
| 2014 | 40 | 55 | 100 | 285 | 80 | 0 | Ozone |
What This Means for Monterey County Residents
Monterey, California has received an Air Quality Grade of C (64/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 42 falls in the "Good" range.
The primary pollutant affecting this area is Ground-Level Ozone. Over the past 5 years, this area has averaged 3 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity. The American Lung Association's State of the Air report provides additional context on long-term health risks from air pollution exposure.
Related Cities in California
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Frequently Asked Questions
Monterey, California has a current median AQI of 42, which falls in the "Good" range. The area has received an Air Quality Grade of C (64/100) based on 10 years of EPA monitoring data.
Air quality in Monterey, California is stable over the past decade. The median AQI has changed by +2 points from 2014 to 2023.
Monterey, California averages 3 unhealthy air quality days per year over the past 5 years. On these days, sensitive groups including children, the elderly, and those with respiratory conditions should limit outdoor activity.
The primary pollutant affecting Monterey, California is Ground-Level Ozone. This is the dominant contributor to elevated AQI readings in the Monterey County area.
Monterey, California averages 3 unhealthy air days per year. This is relatively low, making it a reasonable choice for asthma sufferers. The primary pollutant is Ground-Level Ozone, which is a known asthma trigger.
With a median AQI of 42 (Good), outdoor exercise in Monterey, California is generally safe year-round. Monterey, California averages 3 days per year when athletes should move workouts indoors.