Riverside Air Quality in 2023

In 2023, Riverside's air quality (Riverside-San Bernardino-Ontario, CA area) had a median daily AQI of 81 (Moderate) across 365 monitored days. 141 days (38.6%) reached Unhealthy for Sensitive Groups or worse, 35 were Good, and the year's peak AQI was 660 (Hazardous). Ground-level ozone set the daily AQI on 187 of those days. The cleanest month of 2023 was March (median AQI 55, 0 days above 100) and the worst was July (median 190, 31 days above 100, peak 517).

81
Median AQI
Moderate
141
Days above AQI 100
38.6% of 365 days
174
90th percentile AQI
worst 1 day in 10
660
Peak AQI
Hazardous
O3
Main pollutant
187 of 365 days
35
Good days
9.6% of days
  • Good: 9.6%
  • Moderate: 51.8%
  • Unhealthy for Sensitive Groups: 21.4%
  • Unhealthy or worse: 17.3%

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.

Recommended: Coway AP-1512HH MightyTrue HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft

Check Price on Amazon →

As an Amazon Associate, we earn from qualifying purchases.

QUICK ANSWER

How was Riverside's air quality in 2023?

Moderate on a typical day: median AQI 81, with 141 days above AQI 100 out of 365 monitored — the 2nd cleanest of 7 years on record for the area.

  • Peak AQI in 2023: 660 (Hazardous).
  • Ground-level ozone was the main pollutant on 187 days.
  • Cleanest month: March; worst: July.

Frequently asked questions

What was the average AQI in Riverside in 2023?

EPA's Air Quality System puts Riverside's (Riverside-San Bernardino-Ontario, CA) median daily AQI for 2023 at 81, which is Moderate. 141 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 660.

Which month had the worst air quality in Riverside in 2023?

The cleanest month of 2023 was March (median AQI 55, 0 days above 100) and the worst was July (median 190, 31 days above 100, peak 517).

Was 2023 a good or bad year for Riverside's air?

Among the 7 years EPA has published for the area (2019–2025), 2023 ranks 2nd cleanest by days above AQI 100. 2023's median of 81 is below the area's typical annual median of 89.

Riverside month by month in 2023

Riverside air quality month by month, 2023 (Riverside-San Bernardino-Ontario, CA, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January3159099PM2.5
February28553177PM2.5
Marchcleanest3155078PM2.5
April3010317660O3
May3110517230O3
June309713201O3
Julyworst3119031517O3
August3115023205O3
September3011220228O3
October317212170O3
November30612143PM2.5
December31673146PM2.5

How 2023 compares

Among the 7 years EPA has published for the area (2019–2025), 2023 ranks 2nd cleanest by days above AQI 100.

2023's median of 81 is below 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.