Sacramento Air Quality in 2021

In 2021, Sacramento's air quality (Sacramento--Roseville--Arden-Arcade, CA area) had a median daily AQI of 64 (Moderate) across 365 monitored days. 58 days (15.9%) reached Unhealthy for Sensitive Groups or worse, 97 were Good, and the year's peak AQI was 692 (Hazardous). Ground-level ozone set the daily AQI on 201 of those days. The cleanest month of 2021 was February (median AQI 48, 0 days above 100) and the worst was August (median 154, 23 days above 100, peak 692).

64
Median AQI
Moderate
58
Days above AQI 100
15.9% of 365 days
126
90th percentile AQI
worst 1 day in 10
692
Peak AQI
Hazardous
O3
Main pollutant
201 of 365 days
97
Good days
26.6% of days
  • Good: 26.6%
  • Moderate: 57.5%
  • Unhealthy for Sensitive Groups: 10.4%
  • Unhealthy or worse: 5.5%

Reduce Indoor Ozone in Sacramento

Today's main pollutant in Sacramento is ground-level ozone (AQI 29). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.

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QUICK ANSWER

How was Sacramento's air quality in 2021?

Moderate on a typical day: median AQI 64, with 58 days above AQI 100 out of 365 monitored — the 7th cleanest of 7 years on record for the area.

  • Peak AQI in 2021: 692 (Hazardous).
  • Ground-level ozone was the main pollutant on 201 days.
  • Cleanest month: February; worst: August.

Frequently asked questions

What was the average AQI in Sacramento in 2021?

EPA's Air Quality System puts Sacramento's (Sacramento--Roseville--Arden-Arcade, CA) median daily AQI for 2021 at 64, which is Moderate. 58 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 692.

Which month had the worst air quality in Sacramento in 2021?

The cleanest month of 2021 was February (median AQI 48, 0 days above 100) and the worst was August (median 154, 23 days above 100, peak 692).

Was 2021 a good or bad year for Sacramento's air?

Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 7th cleanest by days above AQI 100 — the worst year on record here. 2021's median of 64 is above the area's typical annual median of 58.

Sacramento month by month in 2021

Sacramento air quality month by month, 2021 (Sacramento--Roseville--Arden-Arcade, CA, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January3159093PM2.5
Februarycleanest2848093O3
March3148064O3
April30551105O3
May31621122O3
June30793136O3
July3110116164O3
Augustworst3115423692PM2.5
September309312151O3
October31542115PM2.5
November3062098PM2.5
December3167085PM2.5

How 2021 compares

Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 7th cleanest by days above AQI 100 — the worst year on record here.

2021's median of 64 is above the area's typical annual median of 58.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Sacramento

The latest EPA AirNow observation puts Sacramento's AQI at 29 (O3). The figures above are multi-year annual statistics, not today's reading.

View current Sacramento air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Sacramento--Roseville--Arden-Arcade, 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.