Riverside Air Quality in 2025

In 2025, Riverside's air quality (Riverside-San Bernardino-Ontario, CA area) had a median daily AQI of 87 (Moderate) across 365 monitored days. 136 days (37.3%) reached Unhealthy for Sensitive Groups or worse, 27 were Good, and the year's peak AQI was 365 (Hazardous). Ground-level ozone set the daily AQI on 207 of those days. The cleanest month of 2025 was October (median AQI 77, 1 day above 100) and the worst was August (median 156, 27 days above 100, peak 202).

87
Median AQI
Moderate
136
Days above AQI 100
37.3% of 365 days
161
90th percentile AQI
worst 1 day in 10
365
Peak AQI
Hazardous
O3
Main pollutant
207 of 365 days
27
Good days
7.4% of days
  • Good: 7.4%
  • Moderate: 55.3%
  • Unhealthy for Sensitive Groups: 22.7%
  • Unhealthy or worse: 14.5%

Extra Protection for Riverside Homes

Air quality in Riverside is moderate (AQI 58), 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

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QUICK ANSWER

How was Riverside's air quality in 2025?

Moderate on a typical day: median AQI 87, with 136 days above AQI 100 out of 365 monitored — the 1st cleanest of 7 years on record for the area.

  • Peak AQI in 2025: 365 (Hazardous).
  • Ground-level ozone was the main pollutant on 207 days.
  • Cleanest month: October; worst: August.

Frequently asked questions

What was the average AQI in Riverside in 2025?

EPA's Air Quality System puts Riverside's (Riverside-San Bernardino-Ontario, CA) median daily AQI for 2025 at 87, which is Moderate. 136 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 365.

Which month had the worst air quality in Riverside in 2025?

The cleanest month of 2025 was October (median AQI 77, 1 day above 100) and the worst was August (median 156, 27 days above 100, peak 202).

Was 2025 a good or bad year for Riverside's air?

Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 1st cleanest by days above AQI 100 — the best year on record here. 2025's median of 87 is in line with the area's typical annual median of 89.

Riverside month by month in 2025

Riverside air quality month by month, 2025 (Riverside-San Bernardino-Ontario, CA, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January31644365PM2.5
February28643164PM2.5
March31646174O3
April308610154O3
May3110819169O3
June3015123207O3
July3113627201O3
Augustworst3115627202O3
September30878166O3
Octobercleanest31771119O3
November30683109PM2.5
December31735162PM2.5

How 2025 compares

Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 1st cleanest by days above AQI 100 — the best year on record here.

2025's median of 87 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 58 (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.