Las Vegas Best & Worst AQI Days: Air Quality Guide
The worst air quality day on record for Las Vegas (Las Vegas-Henderson-Paradise, NV area) was September 8, 2022, when the daily AQI reached 480 (Hazardous), set by coarse dust (PM10). Across 2,557 monitored days in 2019–2025, 10 of the 10 worst days were Unhealthy (AQI 151+) or worse; 6 of the 10 were driven by coarse dust (PM10) and 4 by fine particulate matter (PM2.5), and 4 of them fell in 2022. The cleanest day was December 31, 2019 at AQI 10 (Good); the 10 best days span 6 different years.
Reduce Indoor Ozone in Las Vegas
Today's main pollutant in Las Vegas is ground-level ozone (AQI 31). 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.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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When were Las Vegas's worst and best air quality days?
Worst: September 8, 2022, AQI 480 (Hazardous, PM10). Best: December 31, 2019, AQI 10 (Good). Based on 2,557 EPA-monitored days in the Las Vegas-Henderson-Paradise, NV area, 2019–2025.
- ✓10 of the 10 worst days were Unhealthy (AQI 151+) or worse; the 10th-worst was AQI 158 (Unhealthy).
- ✓Coarse dust (PM10) drove 6 of the 10 worst days.
- ✓2022 accounts for 4 of the 10 worst days.
Frequently asked questions
What was the worst air quality day in Las Vegas?▾
September 8, 2022: the Las Vegas-Henderson-Paradise, NV area's daily AQI hit 480 (Hazardous), driven by coarse dust (PM10). That is the highest of 2,557 monitored days in 2019–2025.
What was the best air quality day in Las Vegas?▾
December 31, 2019, with a daily AQI of 10 (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 Las Vegas's worst air quality day in 2025?▾
July 18, 2025, AQI 138 (Unhealthy for Sensitive Groups), set by fine particulate matter (PM2.5), in wildfire smoke season.
Which pollutant causes Las Vegas's worst air days?▾
Coarse dust (PM10) set the AQI on 6 of the 10 worst days; fine particulate matter (PM2.5) on 4. The tables above list the defining pollutant for every day.
Las Vegas's 10 worst air quality days, 2019–2025
Highest daily AQI recorded for the Las Vegas-Henderson-Paradise, NV area (EPA AQS). The daily AQI is the highest reading from any monitor in the area that day.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2022 page) | 480 | Hazardous | PM10 — coarse dust (PM10) |
| 2 | (2022 page) | 351 | Hazardous | PM10 — coarse dust (PM10) |
| 3 | (2022 page) | 260 | Very Unhealthy | PM10 — coarse dust (PM10) |
| 4 | (2023 page) | 197 | Unhealthy | PM10 — coarse dust (PM10) |
| 5 | (2022 page) | 197 | Unhealthy | PM10 — coarse dust (PM10) |
| 6 | (2021 page) | 183 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 7 | (2020 page) | 174 | Unhealthy | PM10 — coarse dust (PM10) |
| 8 | (2024 page) | 170 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 9 | (2020 page) | 160 | Unhealthy | PM2.5 — fine particulate matter (PM2.5) |
| 10 | (2020 page) | 158 | Unhealthy | PM2.5 — fine particulate matter (PM2.5) |
Worst day of each year in Las Vegas
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 | 122 | Unhealthy for Sensitive Groups | O3 — ground-level ozone, in peak ozone season | |
| 2020 | 174 | Unhealthy | PM10 — coarse dust (PM10) | |
| 2021 | 183 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2022 | 480 | Hazardous | PM10 — coarse dust (PM10) | |
| 2023 | 197 | Unhealthy | PM10 — coarse dust (PM10) | |
| 2024 | 170 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2025 | 138 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
Las Vegas's 10 best air quality days, 2019–2025
Lowest daily AQI recorded for the Las Vegas-Henderson-Paradise, NV area. Ties are listed most recent first.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2019 page) | 10 | Good | CO — carbon monoxide |
| 2 | (2023 page) | 31 | Good | O3 — ground-level ozone |
| 3 | (2024 page) | 33 | Good | O3 — ground-level ozone |
| 4 | (2021 page) | 33 | Good | O3 — ground-level ozone |
| 5 | (2024 page) | 34 | Good | PM2.5 — fine particulate matter (PM2.5) |
| 6 | (2020 page) | 34 | Good | O3 — ground-level ozone |
| 7 | (2020 page) | 34 | Good | O3 — ground-level ozone |
| 8 | (2019 page) | 34 | Good | O3 — ground-level ozone |
| 9 | (2025 page) | 35 | Good | O3 — ground-level ozone |
| 10 | (2024 page) | 35 | Good | O3 — ground-level ozone |
Right now in Las Vegas
The latest EPA AirNow observation puts Las Vegas's AQI at 31 (O3). The days above are historical records, not today's reading.
View current Las Vegas air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Las Vegas-Henderson-Paradise, NV), 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.