Riverside Air Quality in 2020

In 2020, Riverside's air quality (Riverside-San Bernardino-Ontario, CA area) had a median daily AQI of 98 (Moderate) across 366 monitored days. 176 days (48.1%) reached Unhealthy for Sensitive Groups or worse, 23 were Good, and the year's peak AQI was 584 (Hazardous). Ground-level ozone set the daily AQI on 208 of those days. The cleanest month of 2020 was March (median AQI 54, 0 days above 100) and the worst was August (median 161, 31 days above 100, peak 236).

98
Median AQI
Moderate
176
Days above AQI 100
48.1% of 366 days
187
90th percentile AQI
worst 1 day in 10
584
Peak AQI
Hazardous
O3
Main pollutant
208 of 366 days
23
Good days
6.3% of days
  • Good: 6.3%
  • Moderate: 45.6%
  • Unhealthy for Sensitive Groups: 22.4%
  • Unhealthy or worse: 25.7%

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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QUICK ANSWER

How was Riverside's air quality in 2020?

Moderate on a typical day: median AQI 98, with 176 days above AQI 100 out of 366 monitored — the 7th cleanest of 7 years on record for the area.

  • Peak AQI in 2020: 584 (Hazardous).
  • Ground-level ozone was the main pollutant on 208 days.
  • Cleanest month: March; worst: August.

Frequently asked questions

What was the average AQI in Riverside in 2020?

EPA's Air Quality System puts Riverside's (Riverside-San Bernardino-Ontario, CA) median daily AQI for 2020 at 98, which is Moderate. 176 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 584.

Which month had the worst air quality in Riverside in 2020?

The cleanest month of 2020 was March (median AQI 54, 0 days above 100) and the worst was August (median 161, 31 days above 100, peak 236).

Was 2020 a good or bad year for Riverside's air?

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 7th cleanest by days above AQI 100 — the worst year on record here. 2020's median of 98 is above the area's typical annual median of 89.

Riverside month by month in 2020

Riverside air quality month by month, 2020 (Riverside-San Bernardino-Ontario, CA, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January31725207PM2.5
February29692105PM2.5
Marchcleanest3154086O3
April30669197O3
May3113322212O3
June3014224584O3
July3116130215O3
Augustworst3116131236O3
September3016327230O3
October3112222340O3
November30812150PM2.5
December31662154PM2.5

How 2020 compares

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 7th cleanest by days above AQI 100 — the worst year on record here.

2020's median of 98 is above 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.