Metro area air quality · 2025
Riverside-San Bernardino-Ontario, CA
Median AQI 87 (Moderate). 7.4% of monitored days rated Good across this metro's EPA monitoring network.
- 87
- Median AQI
- 7.4%
- Good-air days
- 53
- Unhealthy days
- 0%
- Cleaner than US metros
Riverside-San Bernardino-Ontario, CA posted a 2025 median AQI of 87 (Moderate) with 7.4% Good days
According to the U.S. EPA Air Quality System, the Riverside-San Bernardino-Ontario, CA CBSA recorded a median AQI of 87 across 365 monitored days in 2025, with 7.4% rated Good and 53 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 Riverside-San Bernardino-Ontario, CA CBSA's 7.4% Good-day share places it cleaner than 0% of US metros in 2025.
- Closest median-AQI peer
- Phoenix-Mesa-Scottsdale, AZ (6.6% Good, median AQI 78) is the closest nationwide median-AQI peer to Riverside-San Bernardino-Ontario, CA.
- 2020–2025 Good-day shift
- Riverside-San Bernardino-Ontario, CA's Good-day share moved +1.0 points from 2020 to 2025 (median AQI -11).
- Median AQI
- Median AQI: 87
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
Riverside-San Bernardino-Ontario, CA lands in the lower Good-day tercile (7.4% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs moderate, among the more polluted US metros, with a median AQI of 87 and 7.4% of 365 monitored days in the Good band.
- 87
- median AQI · Moderate
- 7.4%
- days rated Good
- 0%
- cleaner than US metros
- 365
- worst single reading
53 days reached Unhealthy or worse across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Riverside-San Bernardino-Ontario, CA metro's Unhealthy-category days fell from 71 to 48 between the 2024 and 2025 EPA annual releases, a change of -23 days.
- Riverside-San Bernardino-Ontario, CA metro's peak single-day AQI fell from 593 to 365 between the 2024 and 2025 EPA annual releases, a change of -228 points.
- Riverside-San Bernardino-Ontario, CA metro's median AQI fell from 97 to 87 between the 2024 and 2025 EPA annual releases, a change of -10 points.
Riverside-San Bernardino-Ontario, CA lands in the lower Good-day tercile (7.4% Good), a thinner clean-air share than most CBSA peers here. Signature read: 7.4% Good-day share (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 87 over 365 measured days in 2025 (Moderate / Very Poor). The monitored-day split lands at 27 Good (7%), 202 Moderate (55%), and 83 Unhealthy-for-Sensitive-Groups (23%). The 90th-percentile AQI finished at 161; the highest single-day reading hit 365 (Hazardous).
Across 2020–2025, Good-day share shifted +1.0 points and median AQI moved -11 (improving). The annual record contains 53 days at Unhealthy or worse. Metros with comparable AQI profiles include Phoenix-Mesa-Scottsdale, AZ (6.6% good, AQI 78); Los Angeles-Long Beach-Anaheim, CA (10.7% good, AQI 74); Bakersfield, CA (17.5% good, AQI 70).
Air Quality Summary
Median AQI
87
Moderate
Good Days
7.4%
27 of 365 days
Max AQI
365
Hazardous
Health Grade
Very Poor
90th pct: 161
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
27
7%
Moderate
202
55%
USG
83
23%
Unhealthy
48
13%
Very Unhealthy
4
1%
Hazardous
1
0%
Health Impact Assessment
The Riverside-San Bernardino-Ontario, CA metro area's air quality is rated Very Poor based on 7.4% good air days. There were 53 unhealthy days in 2025 when outdoor activity should be limited.
Air quality posed significant health risk in 2025. Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, pregnant women, and adults over 65, should monitor AirNow.gov alerts and limit outdoor activity on Unhealthy (AQI 151+) and Very Unhealthy (201+) days. Peak readings reached AQI 365, well into the Hazardous range.
Sensitive group advisory
People with asthma, COPD, heart disease, children, pregnant women, and adults 65+ should follow EPA AQI alerts daily and limit outdoor exertion when AQI exceeds 100. Real-time conditions: airnow.gov.
How does the Riverside-San Bernardino-Ontario, CA metro compare?
How Riverside-San Bernardino-Ontario, CA compares
5-Year Air Quality Trend
Air quality is improving in the Riverside-San Bernardino-Ontario, CA metro. Highest Good-day share: 2023 (12.8%, 35 of 273 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 23 | 167 | 72 | 98 | 584 |
| 2021 | 9 | 190 | 69 | 97 | 486 |
| 2022 | 9 | 206 | 61 | 87 | 1683 |
| 2023 | 35 | 187 | 51 | 84 | 660 |
| 2024 | 26 | 176 | 71 | 97 | 593 |
| 2025 | 27 | 202 | 48 | 87 | 365 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Riverside-San Bernardino-Ontario, CA (87).
Phoenix-Mesa-Scottsdale, AZ
Median AQI 78 · 6.6% Good-day share
Los Angeles-Long Beach-Anaheim, CA
Median AQI 74 · 10.7% Good-day share
Bakersfield, CA
Median AQI 70 · 17.5% Good-day share
El Paso, TX
Median AQI 70 · 18.1% Good-day share
San Diego-Carlsbad, CA
Median AQI 67 · 17.5% Good-day share
El Centro, CA
Median AQI 64 · 27.7% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Riverside-San Bernardino-Ontario, CA's 53 (independent of median AQI).
Las Cruces, NM
21 unhealthy-or-worse days · median AQI 61
Duluth, MN-WI
12 unhealthy-or-worse days · median AQI 42
Houston-The Woodlands-Sugar Land, TX
11 unhealthy-or-worse days · median AQI 63
Fairbanks, AK
10 unhealthy-or-worse days · median AQI 44
Bemidji, MN
9 unhealthy-or-worse days · median AQI 36
Deming, NM
9 unhealthy-or-worse days · median AQI 17
Frequently Asked Questions
How many unhealthy air days does Riverside-San Bernardino-Ontario, CA have? ▼
What is the air quality in the Riverside-San Bernardino-Ontario, CA metro area? ▼
Is air quality in Riverside-San Bernardino-Ontario, CA getting better or worse? ▼
What does AQI 87 mean for health? ▼
How does Riverside-San Bernardino-Ontario, CA compare to other metro areas? ▼
What is the 90th percentile AQI for Riverside-San Bernardino-Ontario, CA? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Riverside-San Bernardino-Ontario, 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, Riverside-San Bernardino-Ontario, CA · 2020–2025