Sacramento Air Quality in Winter

Across 2019–2025, Sacramento's winter (December–February) air quality had a median AQI of 57 (Moderate) over 632 monitored days in the Sacramento--Roseville--Arden-Arcade, CA area. 2.1% of winter days (13 of 632) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 78.5% of days. The cleanest winter on record here was 2023 (median AQI 55, 0 days above 100) and the worst was 2022 (median 73, 9 days above 100, peak AQI 118).

57
Median AQI
Moderate
2.1%
Days above AQI 100
13 of 632 days
85
90th percentile AQI
worst 1 day in 10
118
Peak AQI
Unhealthy for Sensitive Groups
PM2.5
Main pollutant
78.5% of days
33.7%
Good days
213 of 632
  • Good: 33.7%
  • Moderate: 64.2%
  • Unhealthy for Sensitive Groups: 2.1%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in Sacramento in winter?

Moderate on a typical day: median AQI 57 across 2019–2025, with 2.1% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 33.7% of winter days were Good (AQI 0–50), 64.2% Moderate (51–100).
  • 13 days of 632 reached AQI 101+; the winter peak was 118.
  • Cleanest month: February; worst month: January.

Frequently asked questions

What is the air quality like in Sacramento in winter?

Across 2019–2025, the median daily AQI in Sacramento in winter was 57 (Moderate). 33.7% of days were Good, 64.2% Moderate, and 2.1% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.

Is winter a good time for outdoor exercise in Sacramento?

A typical winter day in Sacramento is Moderate (median AQI 57): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 48 of winter days (2.1%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Which pollutant causes Sacramento's winter air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 78.5% of winter days in Sacramento. The highest winter AQI recorded in 2019–2025 was 118 (Unhealthy for Sensitive Groups), in 2022.

Sacramento winter air quality, year by year

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

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
201990523116PM2.5
20209162095PM2.5
20219056093PM2.5
2022worst90739118PM2.5
2023cleanest9055094PM2.5
202491531118PM2.5
20259058084PM2.5

What winter air means in Sacramento

A typical winter day in Sacramento is Moderate (median AQI 57): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 48 of winter days (2.1%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Winter's median AQI of 57 is in line with Sacramento's whole-year median of 58, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Sacramento runs above the national Winter norm; 2.1% of its Winter days topped AQI 100 versus 0.6% nationally (above average).

Within the season, February is the cleanest month (median AQI 52, 1.0% of days above 100) and January the worst (median 58, 2.8% above 100).

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

Right now in Sacramento

The latest EPA AirNow observation puts Sacramento's AQI at 43 (PM2.5). The figures above are multi-year season 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.