Visalia Air Quality in 2021
In 2021, Visalia's air quality (Visalia-Porterville, CA area) had a median daily AQI of 81 (Moderate) across 365 monitored days. 134 days (36.7%) reached Unhealthy for Sensitive Groups or worse, 49 were Good, and the year's peak AQI was 961 (Hazardous). Fine particulate matter (PM2.5) set the daily AQI on 187 of those days. The cleanest month of 2021 was March (median AQI 50, 0 days above 100) and the worst was July (median 129, 28 days above 100, peak 174).
- Good: 13.4%
- Moderate: 49.9%
- Unhealthy for Sensitive Groups: 25.5%
- Unhealthy or worse: 11.2%
Extra Protection for Visalia Homes
Air quality in Visalia is moderate (AQI 57), with particle pollution 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 Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How was Visalia's air quality in 2021?
Moderate on a typical day: median AQI 81, with 134 days above AQI 100 out of 365 monitored — the 6th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2021: 961 (Hazardous).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 187 days.
- ✓Cleanest month: March; worst: July.
Frequently asked questions
What was the average AQI in Visalia in 2021?▾
EPA's Air Quality System puts Visalia's (Visalia-Porterville, CA) median daily AQI for 2021 at 81, which is Moderate. 134 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 961.
Which month had the worst air quality in Visalia in 2021?▾
The cleanest month of 2021 was March (median AQI 50, 0 days above 100) and the worst was July (median 129, 28 days above 100, peak 174).
Was 2021 a good or bad year for Visalia's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 6th cleanest by days above AQI 100. 2021's median of 81 is above the area's typical annual median of 71.
Visalia month by month in 2021
Visalia air quality month by month, 2021 (Visalia-Porterville, CA, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 76 | 9 | 124 | PM2.5 |
| February | 28 | 61 | 2 | 104 | PM2.5 |
| Marchcleanest | 31 | 50 | 0 | 66 | PM2.5 |
| April | 30 | 60 | 1 | 122 | O3 |
| May | 31 | 77 | 5 | 133 | O3 |
| June | 30 | 101 | 16 | 187 | O3 |
| Julyworst | 31 | 129 | 28 | 174 | O3 |
| August | 31 | 136 | 25 | 179 | O3 |
| September | 30 | 116 | 21 | 961 | PM2.5 |
| October | 31 | 111 | 16 | 205 | PM2.5 |
| November | 30 | 87 | 7 | 120 | PM2.5 |
| December | 31 | 36 | 4 | 157 | PM2.5 |
How 2021 compares
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 6th cleanest by days above AQI 100.
2021's median of 81 is above the area's typical annual median of 71.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Visalia
The latest EPA AirNow observation puts Visalia's AQI at 57 (PM10). The figures above are multi-year annual statistics, not today's reading.
View current Visalia air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Visalia-Porterville, 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.