Metro area air quality · 2025
Santa Cruz-Watsonville, CA
Median AQI 35 (Good). 87.7% of monitored days rated Good across this metro's EPA monitoring network.
- 35
- Median AQI
- 87.7%
- Good-air days
- 0
- Unhealthy days
- 82%
- Cleaner than US metros
Santa Cruz-Watsonville, CA posted a 2025 median AQI of 35 (Good) with 87.7% Good days
According to the U.S. EPA Air Quality System, the Santa Cruz-Watsonville, CA CBSA recorded a median AQI of 35 across 365 monitored days in 2025, with 87.7% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US metros
- The Santa Cruz-Watsonville, CA CBSA's 87.7% Good-day share places it cleaner than 82% of US metros in 2025.
- Closest median-AQI peer
- Baraboo, WI (75.6% Good, median AQI 35) is the closest nationwide median-AQI peer to Santa Cruz-Watsonville, CA.
- 2020–2025 Good-day shift
- Santa Cruz-Watsonville, CA's Good-day share moved +14.4 points from 2020 to 2025 (median AQI -4).
- Median AQI
- Median AQI: 35
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
Santa Cruz-Watsonville, CA sits in the upper Good-day tercile among EPA CBSA metros on this site (87.7% of 365 monitored days). On the EPA scale the metro runs good, cleaner than most US metros, with a median AQI of 35 and 87.7% of 365 monitored days in the Good band.
- 35
- median AQI · Good
- 87.7%
- days rated Good
- 82%
- cleaner than US metros
- 71
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Santa Cruz-Watsonville, CA metro's Good-day share rose from 80.1% to 87.7% between the 2024 and 2025 EPA annual releases, a change of +7.6 percentage points.
- Santa Cruz-Watsonville, CA metro's median AQI fell from 39 to 35 between the 2024 and 2025 EPA annual releases, a change of -4 points.
Santa Cruz-Watsonville, CA sits in the upper Good-day tercile among EPA CBSA metros on this site (87.7% of 365 monitored days). Signature read: 87.7% Good-day share (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 35 over 365 measured days in 2025 (Good / Good). The monitored-day split lands at 320 Good (88%), 45 Moderate (12%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 53; the highest single-day reading hit 71 (Moderate).
Across 2020–2025, Good-day share shifted +14.4 points and median AQI moved -4 (improving). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Baraboo, WI (75.6% good, AQI 35); Effingham, IL (95.5% good, AQI 35); Ithaca, NY (93.2% good, AQI 35).
Air Quality Summary
Median AQI
35
Good
Good Days
87.7%
320 of 365 days
Max AQI
71
Moderate
Health Grade
Good
90th pct: 53
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
320
88%
Moderate
45
12%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Santa Cruz-Watsonville, CA metro area's air quality is rated Good based on 87.7% good air days. No unhealthy air days were recorded in 2025.
Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.
How does the Santa Cruz-Watsonville, CA metro compare?
How Santa Cruz-Watsonville, CA compares
5-Year Air Quality Trend
Air quality is improving in the Santa Cruz-Watsonville, CA metro. Highest Good-day share: 2025 (87.7%, 320 of 365 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 261 | 85 | 10 | 39 | 624 |
| 2021 | 298 | 67 | 0 | 37 | 80 |
| 2022 | 287 | 78 | 0 | 35 | 93 |
| 2023 | 300 | 64 | 0 | 36 | 130 |
| 2024 | 293 | 73 | 0 | 39 | 80 |
| 2025 | 320 | 45 | 0 | 35 | 71 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Santa Cruz-Watsonville, CA (35).
Baraboo, WI
Median AQI 35 · 75.6% Good-day share
Effingham, IL
Median AQI 35 · 95.5% Good-day share
Ithaca, NY
Median AQI 35 · 93.2% Good-day share
Kinston, NC
Median AQI 35 · 97.5% Good-day share
Meridian, MS
Median AQI 35 · 94.6% Good-day share
Morehead City, NC
Median AQI 35 · 96.2% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Santa Cruz-Watsonville, CA's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Aberdeen, WA
0 unhealthy-or-worse days · median AQI 22
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, GA
0 unhealthy-or-worse days · median AQI 46
Albany, OR
0 unhealthy-or-worse days · median AQI 27
Frequently Asked Questions
How many unhealthy air days does Santa Cruz-Watsonville, CA have? ▼
What is the air quality in the Santa Cruz-Watsonville, CA metro area? ▼
Is air quality in Santa Cruz-Watsonville, CA getting better or worse? ▼
What does AQI 35 mean for health? ▼
How does Santa Cruz-Watsonville, CA compare to other metro areas? ▼
What is the 90th percentile AQI for Santa Cruz-Watsonville, CA? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Santa Cruz-Watsonville, CA, 2025. See our methodology for how AQI, median, and coverage figures are computed.
Read our methodology , how this data is sourced, computed, and verified.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Santa Cruz-Watsonville, CA · 2020–2025