Riverside Air Quality in 2019
In 2019, Riverside's air quality (Riverside-San Bernardino-Ontario, CA area) had a median daily AQI of 89 (Moderate) across 365 monitored days. 145 days (39.7%) reached Unhealthy for Sensitive Groups or worse, 20 were Good, and the year's peak AQI was 213 (Very Unhealthy). Ground-level ozone set the daily AQI on 205 of those days. The cleanest month of 2019 was December (median AQI 62, 1 day above 100) and the worst was August (median 169, 31 days above 100, peak 201).
- Good: 5.5%
- Moderate: 54.8%
- Unhealthy for Sensitive Groups: 21.6%
- Unhealthy or worse: 18.1%
Extra Protection for Riverside Homes
Air quality in Riverside is moderate (AQI 55), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
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How was Riverside's air quality in 2019?
Moderate on a typical day: median AQI 89, with 145 days above AQI 100 out of 365 monitored — the 3rd cleanest of 7 years on record for the area.
- ✓Peak AQI in 2019: 213 (Very Unhealthy).
- ✓Ground-level ozone was the main pollutant on 205 days.
- ✓Cleanest month: December; worst: August.
Frequently asked questions
What was the average AQI in Riverside in 2019?▾
EPA's Air Quality System puts Riverside's (Riverside-San Bernardino-Ontario, CA) median daily AQI for 2019 at 89, which is Moderate. 145 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 213.
Which month had the worst air quality in Riverside in 2019?▾
The cleanest month of 2019 was December (median AQI 62, 1 day above 100) and the worst was August (median 169, 31 days above 100, peak 201).
Was 2019 a good or bad year for Riverside's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 3rd cleanest by days above AQI 100. 2019's median of 89 is in line with the area's typical annual median of 89.
Riverside month by month in 2019
Riverside air quality month by month, 2019 (Riverside-San Bernardino-Ontario, CA, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 59 | 2 | 121 | PM2.5 |
| February | 28 | 58 | 1 | 118 | PM2.5 |
| March | 31 | 69 | 2 | 150 | O3 |
| April | 30 | 90 | 11 | 150 | O3 |
| May | 31 | 77 | 5 | 147 | O3 |
| June | 30 | 138 | 23 | 192 | O3 |
| July | 31 | 166 | 31 | 213 | O3 |
| Augustworst | 31 | 169 | 31 | 201 | O3 |
| September | 30 | 114 | 18 | 195 | O3 |
| October | 31 | 90 | 11 | 190 | O3 |
| November | 30 | 76 | 9 | 129 | PM2.5 |
| Decembercleanest | 31 | 62 | 1 | 107 | PM2.5 |
How 2019 compares
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 3rd cleanest by days above AQI 100.
2019's median of 89 is in line with the area's typical annual median of 89.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Riverside
The latest EPA AirNow observation puts Riverside's AQI at 55 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current Riverside air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Riverside-San Bernardino-Ontario, CA), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.