Sacramento Best & Worst AQI Days: Air Quality Guide
The worst air quality day on record for Sacramento (Sacramento--Roseville--Arden-Arcade, CA area) was August 23, 2021, when the daily AQI reached 692 (Hazardous), set by fine particulate matter (PM2.5), in wildfire smoke season. Across 2,557 monitored days in 2019–2025, 10 of the 10 worst days were Unhealthy (AQI 151+) or worse; 10 of the 10 were driven by fine particulate matter (PM2.5), and 6 of them fell in 2021. The cleanest day was June 13, 2021 at AQI 28 (Good); the 10 best days span 6 different years.
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When were Sacramento's worst and best air quality days?
Worst: August 23, 2021, AQI 692 (Hazardous, PM2.5). Best: June 13, 2021, AQI 28 (Good). Based on 2,557 EPA-monitored days in the Sacramento--Roseville--Arden-Arcade, CA area, 2019–2025.
- ✓10 of the 10 worst days were Unhealthy (AQI 151+) or worse; the 10th-worst was AQI 254 (Very Unhealthy).
- ✓Fine particulate matter (PM2.5) drove 10 of the 10 worst days.
- ✓2021 accounts for 6 of the 10 worst days.
Frequently asked questions
What was the worst air quality day in Sacramento?▾
August 23, 2021: the Sacramento--Roseville--Arden-Arcade, CA area's daily AQI hit 692 (Hazardous), driven by fine particulate matter (PM2.5), in wildfire smoke season. That is the highest of 2,557 monitored days in 2019–2025.
What was the best air quality day in Sacramento?▾
June 13, 2021, with a daily AQI of 28 (Good). The daily AQI is the highest reading from any monitor in the area, so even the cleanest day reflects the area's worst monitor.
What was Sacramento's worst air quality day in 2025?▾
July 11, 2025, AQI 143 (Unhealthy for Sensitive Groups), set by ground-level ozone, in peak ozone season.
Which pollutant causes Sacramento's worst air days?▾
Fine particulate matter (PM2.5) set the AQI on 10 of the 10 worst days. The tables above list the defining pollutant for every day.
Sacramento's 10 worst air quality days, 2019–2025
Highest daily AQI recorded for the Sacramento--Roseville--Arden-Arcade, CA area (EPA AQS). The daily AQI is the highest reading from any monitor in the area that day.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2021 page) | 692 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 2 | (2021 page) | 463 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 3 | (2022 page) | 442 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 4 | (2021 page) | 381 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 5 | (2022 page) | 338 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 6 | (2021 page) | 312 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 7 | (2021 page) | 290 | Very Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 8 | (2022 page) | 288 | Very Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 9 | (2021 page) | 262 | Very Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 10 | (2022 page) | 254 | Very Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
Worst day of each year in Sacramento
The single highest-AQI day in each year on record. Click a year for its full month-by-month statistics.
| Year | Worst day | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 2019 | 140 | Unhealthy for Sensitive Groups | O3 — ground-level ozone, in peak ozone season | |
| 2020 | 247 | Very Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2021 | 692 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2022 | 442 | Hazardous | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2023 | 143 | Unhealthy for Sensitive Groups | O3 — ground-level ozone, in peak ozone season | |
| 2024 | 140 | Unhealthy for Sensitive Groups | O3 — ground-level ozone, in peak ozone season | |
| 2025 | 143 | Unhealthy for Sensitive Groups | O3 — ground-level ozone, in peak ozone season |
Sacramento's 10 best air quality days, 2019–2025
Lowest daily AQI recorded for the Sacramento--Roseville--Arden-Arcade, CA area. Ties are listed most recent first.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2021 page) | 28 | Good | PM2.5 — fine particulate matter (PM2.5) |
| 2 | (2023 page) | 31 | Good | O3 — ground-level ozone |
| 3 | (2022 page) | 31 | Good | O3 — ground-level ozone, in peak ozone season |
| 4 | (2019 page) | 31 | Good | O3 — ground-level ozone |
| 5 | (2022 page) | 32 | Good | O3 — ground-level ozone |
| 6 | (2020 page) | 32 | Good | O3 — ground-level ozone |
| 7 | (2019 page) | 32 | Good | PM2.5 — fine particulate matter (PM2.5) |
| 8 | (2019 page) | 32 | Good | O3 — ground-level ozone |
| 9 | (2024 page) | 33 | Good | O3 — ground-level ozone, in peak ozone season |
| 10 | (2019 page) | 33 | Good | O3 — ground-level ozone |
Right now in Sacramento
The latest EPA AirNow observation puts Sacramento's AQI at 43 (PM2.5). The days above are historical records, 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.