Aptos Hills-Larkin Valley, California Air Quality
Aptos Hills-Larkin Valley has a median AQI of 37, earning an air quality grade of A — excellent air quality that ranks better than 74% of US cities. Air quality has remained relatively stable over the past decade. Ground-level ozone is the primary concern, typically peaking on warm sunny days due to vehicle and industrial emissions. In 2025, Aptos Hills-Larkin Valley recorded 148 good air quality days (82% of monitored days).
Population: 2,127 • County: Santa Cruz
Current AQI
Quick Facts
| Current AQI | 10 — Good |
| Air Quality Grade | A |
| Median AQI (2025) | 37 |
| vs. U.S. Cities | Better than 74% |
| Primary Pollutant | Ozone |
| Unhealthy Days/Year | 0 |
| 10-Year Trend | → Stable |
| 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 Aptos Hills-Larkin Valley is sourced from the Santa Cruz AMS monitoring area, located approximately 9 miles from city center. This EPA-certified station continuously tracks ground-level ozone, the primary driver of air quality alerts in this area.
Wildfire smoke is a significant factor in Aptos Hills-Larkin Valley's air quality, with regional fires capable of pushing AQI from Good to Unhealthy within hours during fire season (typically July through October). On smoke-impacted days, staying indoors with windows closed and running an air purifier with a HEPA filter is the most effective protection.
AQI Trend (10 Years)
Air Quality Days by Year
Aptos Hills-Larkin Valley Median AQI by Year
Annual EPA air quality data for Aptos Hills-Larkin Valley — median AQI, day-category breakdown, and primary pollutant per year.
| Year | Median AQI | Good Days | Unhealthy Days | Max AQI | Primary Pollutant |
|---|---|---|---|---|---|
| 2025 | 37 | 148 | — | 71 | Ozone |
| 2024 | 39 | 293 | — | 80 | PM2.5 |
| 2023 | 36 | 300 | 1 | 130 | PM2.5 |
| 2022 | 35 | 287 | — | 93 | PM2.5 |
| 2021 | 37 | 298 | — | 80 | Ozone |
| 2020 | 39 | 261 | 20 | 624 | PM2.5 |
| 2019 | 39 | 291 | — | 74 | PM2.5 |
| 2018 | 41 | 273 | 10 | 177 | PM2.5 |
| 2017 | 39 | 269 | 4 | 130 | PM2.5 |
| 2016 | 35 | 306 | — | 76 | PM2.5 |
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 Aptos Hills-Larkin Valley Air Quality
What is the air quality in Aptos Hills-Larkin Valley today?
The current AQI in Aptos Hills-Larkin Valley 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 Aptos Hills-Larkin Valley getting better or worse?
Air quality in Aptos Hills-Larkin Valley has been stable. The median AQI has risen 2 points (from 35 in 2016 to 37 in 2025).
What is the most common air pollutant in Aptos Hills-Larkin Valley?
Ozone is the primary air pollutant in Aptos Hills-Larkin Valley, responsible for 98 days (54% 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 Aptos Hills-Larkin Valley have per year?
In 2025, Aptos Hills-Larkin Valley recorded 82% good air quality days (148 days) out of 181 monitored days. There were 0 Unhealthy for Sensitive Groups days and 0 Unhealthy days (AQI above 100). The highest single-day AQI recorded was 71.
What air quality grade does Aptos Hills-Larkin Valley receive?
Aptos Hills-Larkin Valley receives an air quality grade of A, placing it better than 74% of US cities. This is based on a median AQI of 37 in 2025, with 148 good air quality days. The EPA monitors air quality in this area continuously using certified monitoring stations.
Air Quality Grade
Better than 74% of US cities
Nearby Cities
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National Rankings
See how Aptos Hills-Larkin Valley compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Aptos Hills-Larkin Valley
Ozone is Aptos Hills-Larkin Valley's primary pollutant. Standard HEPA filters don't capture ozone molecules — you need activated carbon or PECO technology to chemically break them down. We highlight those units here.
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Other Great Options
Molekule Air Pro
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Honeywell HPA300
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