Riverside Air Quality in July

Across 2019–2025, Riverside's July air quality had a median AQI of 161 (Unhealthy) over 217 monitored days in the Riverside-San Bernardino-Ontario, CA area. 94.1% of July days (204 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 95.9% of days. The cleanest July on record here was 2022 (median AQI 159, 26 days above 100) and the worst was 2023 (median 190, 31 days above 100, peak AQI 517).

161
Median AQI
Unhealthy
94.1%
Days above AQI 100
204 of 217 days
206
90th percentile AQI
worst 1 day in 10
517
Peak AQI
Hazardous
O3
Main pollutant
95.9% of days
0.0%
Good days
0 of 217
  • Good: 0.0%
  • Moderate: 6.0%
  • Unhealthy for Sensitive Groups: 32.3%
  • Unhealthy or worse: 61.8%

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.

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QUICK ANSWER

How is the air in Riverside in July?

Unhealthy on a typical day: median AQI 161 across 2019–2025, with 94.1% of July days above AQI 100. Ground-level ozone is the main driver.

  • 0.0% of July days were Good (AQI 0–50), 6.0% Moderate (51–100).
  • 204 days of 217 reached AQI 101+; the July peak was 517.
  • Best July: 2022; worst July: 2023.

Frequently asked questions

What is the air quality like in Riverside in July?

Across 2019–2025, the median daily AQI in Riverside in July was 161 (Unhealthy). 0.0% of days were Good, 6.0% Moderate, and 94.1% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

Is July a good time for outdoor exercise in Riverside?

A typical July day in Riverside is Unhealthy (median AQI 161): everyone should limit prolonged outdoor exertion, and sensitive groups should avoid it; about 94% of July days (94.1%) were at AQI 101+.

Which pollutant causes Riverside's July air quality problems?

Ground-level ozone set the daily AQI on 95.9% of July days in Riverside. The highest July AQI recorded in 2019–2025 was 517 (Hazardous), in 2023.

Riverside July air quality, year by year

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

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193116631213O3
20203116130215O3
20213115630212O3
2022cleanest3115926206O3
2023worst3119031517O3
20243120129227O3
20253113627201O3

What July air means in Riverside

A typical July day in Riverside is Unhealthy (median AQI 161): everyone should limit prolonged outdoor exertion, and sensitive groups should avoid it; about 94% of July days (94.1%) were at AQI 101+.

July's median AQI of 161 is above Riverside's whole-year median of 89, making it one of the area's dirtier periods. Nationally, the median July AQI across every EPA metro area (103,858 metro-days, 2019–2025) is 47, so Riverside runs above the national July norm; 94.1% of its July days topped AQI 100 versus 3.6% nationally (above average).

July is part of Riverside's summer season (June, July, August); the summer page pools all three months.

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 month 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.