Riverside Air Quality in Spring

Across 2019–2025, Riverside's spring (March–May) air quality had a median AQI of 82 (Moderate) over 644 monitored days in the Riverside-San Bernardino-Ontario, CA area. 34.4% of spring days (222 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 66.0% of days. The cleanest spring on record here was 2019 (median AQI 73, 18 days above 100) and the worst was 2022 (median 93, 40 days above 100, peak AQI 1683).

82
Median AQI
Moderate
34.4%
Days above AQI 100
222 of 644 days
150
90th percentile AQI
worst 1 day in 10
1683
Peak AQI
Hazardous
O3
Main pollutant
66.0% of days
9.2%
Good days
59 of 644
  • Good: 9.2%
  • Moderate: 56.4%
  • Unhealthy for Sensitive Groups: 24.8%
  • Unhealthy or worse: 9.6%

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

Check Price on Amazon →

As an Amazon Associate, we earn from qualifying purchases.

QUICK ANSWER

How is the air in Riverside in spring?

Moderate on a typical day: median AQI 82 across 2019–2025, with 34.4% of spring days above AQI 100. Ground-level ozone is the main driver.

  • 9.2% of spring days were Good (AQI 0–50), 56.4% Moderate (51–100).
  • 222 days of 644 reached AQI 101+; the spring peak was 1683.
  • Cleanest month: March; worst month: May.

Frequently asked questions

What is the air quality like in Riverside in spring?

Across 2019–2025, the median daily AQI in Riverside in spring was 82 (Moderate). 9.2% of days were Good, 56.4% Moderate, and 34.4% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.

Is spring a good time for outdoor exercise in Riverside?

A typical spring day in Riverside is Moderate (median AQI 82): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 3 of spring days (34.4%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Which pollutant causes Riverside's spring air quality problems?

Ground-level ozone set the daily AQI on 66.0% of spring days in Riverside. The highest spring AQI recorded in 2019–2025 was 1683 (Hazardous), in 2022.

Riverside spring air quality, year by year

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

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
2019cleanest927318150O3
2020927631212O3
2021929238329O3
2022worst9293401683O3
2023927934660O3
2024928026193O3
2025928735174O3

What spring air means in Riverside

A typical spring day in Riverside is Moderate (median AQI 82): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 3 of spring days (34.4%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Spring's median AQI of 82 is below Riverside's whole-year median of 89, making it one of the area's cleaner periods. Nationally, the median Spring AQI across every EPA metro area (307,196 metro-days, 2019–2025) is 43, so Riverside runs above the national Spring norm; 34.4% of its Spring days topped AQI 100 versus 0.8% nationally (above average).

Within the season, March is the cleanest month (median AQI 61, 5.9% of days above 100) and May the worst (median 105, 57.6% above 100).

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 season 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.