Keep one room clean on smoky days
Shut the windows and run an air purifier sized for the room.
Choosing a purifier →Includes Bishop · EPA monitor readings, 2021 to 2025 · 19,000 people
For today's air and tomorrow's forecast, check AirNow by ZIP code.
About 1 day in 13. That's down from about 67 a year in the early 2000s. Inyo County has the 11th most bad-air days of the 52 California counties with monitors.
Average bad-air days in each month, from 10 years of daily readings since 2016. Most fall in August, September and October.
| Month | Ozone | Fine particles | Dust | All |
|---|---|---|---|---|
| January | 0 | 0.3 | 0.8 | 1.1 |
| February | 0 | 0.1 | 1.7 | 1.8 |
| March | 0 | 0 | 2.6 | 2.6 |
| April | 0.2 | 0.1 | 1.8 | 2.1 |
| May | 0.9 | 0 | 0.5 | 1.4 |
| June | 1.5 | 0.1 | 0.5 | 2.1 |
| July | 2.1 | 0.7 | 0.2 | 3.0 |
| August | 0.9 | 2.7 | 0 | 3.6 |
| September | 0.1 | 3.6 | 0.8 | 4.5 |
| October | 0 | 1.9 | 1.8 | 3.7 |
| November | 0 | 0 | 1.5 | 1.5 |
| December | 0 | 0.6 | 1.1 | 1.7 |
The worst day since 2016 was April 7, 2017: AQI 2234, past the top of the scale at 500, from dust and coarse particles.
The pollutant that pushed the AQI over 100 on each of the 291 bad-air days since 2016.
Bad days here come from both blowing dust and fine particles such as smoke.
The CDC's model counts bad-air days at the county's worst spot, from monitors and satellites. Particles (brown) fill the inside of the ring and ozone (blue) the outside.
| Month | Fine particles | Ozone |
|---|---|---|
| January | 0 | 0 |
| February | 0 | 0 |
| March | 0 | 0 |
| April | 0 | 0.4 |
| May | 0 | 2.9 |
| June | 0 | 5.2 |
| July | 0.1 | 4.3 |
| August | 1.1 | 4.2 |
| September | 1.2 | 1.3 |
| October | 0.8 | 0.2 |
| November | 0.1 | 0 |
| December | 0.1 | 0 |
Bad days here come from dust and fine particles. Filtering the air at home helps with both.
Shut the windows and run an air purifier sized for the room.
Choosing a purifier →Use MERV 13 if your system can take it, and run the fan on smoky days.
Furnace filters →Dust days come with wind. When the forecast calls for high wind or the Weather Service posts a dust warning, plan to stay in.
AirNow →For today's reading and tomorrow's forecast, check AirNow by ZIP code. Its fire and smoke map adds smoke plumes.
Parents: what schools do at each AQI level, and how to plan for smoke and ozone days.
For a clean room on smoky days. Each has a smoke CADR tested by AHAM's independent program and is certified by California as a mechanical cleaner, so it makes no ozone.
143 smoke CADR
The cheapest unit we found with a verified smoke rating. Enough for a bedroom clean room.
$119.99 at Levoit250 smoke CADR
The most verified smoke cleaning per dollar of any qualifying model: 75% more than the 100S-P for $50 more.
$169.99 at Levoit391 smoke CADR
For a big room or a small apartment. Buy the LAP-C601S-WUS version, which CARB lists as mechanical.
$299.99 at LevoitWhy all 3 are Levoit: of the models we checked that pass both tests, these give the most verified smoke cleaning per dollar at each room size. Medify's MA-25 and MA-40 also pass but cost more for the same cleaning.
Ratings from the AHAM Verifide directory and CARB's certified list. Prices from Levoit's site, checked November 7, 2026; they change. We don't earn anything from these links. How to pick a purifier
Bad-air days each year. The striped part is days unhealthy for everyone, over AQI 150. The worst recent year was 2021, with 42 bad-air days.
| Year | Bad-air days | Over 150 |
|---|---|---|
| 2000 | 59 | 27 |
| 2001 | 72 | 40 |
| 2002 | 80 | 41 |
| 2003 | 66 | 24 |
| 2004 | 60 | 25 |
| 2005 | 70 | 24 |
| 2006 | 66 | 19 |
| 2007 | 49 | 11 |
| 2008 | 35 | 13 |
| 2009 | 22 | 17 |
| 2010 | 31 | 18 |
| 2011 | 46 | 13 |
| 2012 | 29 | 14 |
| 2013 | 21 | 11 |
| 2014 | 15 | 9 |
| 2015 | 21 | 9 |
| 2016 | 23 | 8 |
| 2017 | 25 | 9 |
| 2018 | 37 | 11 |
| 2019 | 12 | 6 |
| 2020 | 55 | 32 |
| 2021 | 42 | 18 |
| 2022 | 31 | 13 |
| 2023 | 23 | 10 |
| 2024 | 30 | 13 |
| 2025 | 13 | 4 |
Bad-air days a year, 2021 to 2025. California counties with monitors averaged about 53 bad-air days a year, weighted by population.
From 2021 to 2025, monitors in Inyo County recorded about 28 bad-air days a year with an AQI above 100, which is unhealthy for sensitive groups or worse. The worst year in that stretch was 2021, with 42 bad-air days.
Bad days here come from both blowing dust and fine particles such as smoke. Bad days cluster in August, September and October.
AirNow, run by the EPA and its partners, shows the current AQI and tomorrow's forecast for your ZIP code. Its fire and smoke map adds smoke plumes. On a typical day the AQI in Inyo County is about 59, which is moderate, fine for most people. Check it most in August, September and October, when bad days here cluster.
Day counts come from the EPA's county air quality summaries, which take the worst reading across a county's monitors each day. Monitors here reported on about 365 days a year from 2021 to 2025. A county is large, and your street can be cleaner or worse. CDC's model, which estimates every county from monitors and satellites, gives the worst spot in Inyo County about 14 high-particle days and about 5 high-ozone days a year from 2018 to 2022.
Sources: EPA AirData county AQI summaries (2000 to 2025) and daily county AQI (2016 to 2025); CDC Environmental Public Health Tracking Network modeled PM2.5 and ozone (2001 to 2022). Updated November 8, 2026.