Air quality in Cochise County, AZ

Includes Sierra Vista and Douglas · EPA monitor readings, 2021 to 2025 · 125,000 people

A few bad days a yearMostly ozone
Bad-air days a year
5
days with an AQI over 100

About 1 day in 79. In the early 2000s it was about 4 a year. Cochise County has the 6th most bad-air days of the 13 Arizona counties with monitors.

<1day unhealthy for everyoneAQI over 150, a year
45AQI on a typical dayGood: fine for everyone
May to Julworst monthsOzone on hot afternoons
328worst day since 2016Jan 8, 2025, dust
How to read the AQIThe EPA's air score runs from 0 to 500. Higher is worse. Over 100 counts as a bad-air day.
Typical day 45 (Good)Worst day 328 (Hazardous)
Good0 to 50Moderate51 to 100Sensitive groups101 to 150Unhealthy151 to 200Very unhealthy201 to 300Hazardous301 to 500

When bad air happens in Cochise County

Average bad-air days in each month, from 10 years of daily readings since 2016. Most fall in May, June and July.

Jan0.3
Feb0.1
Mar0
Apr0.4
May0.6
Jun0.5
Jul0.7
Aug0.2
Sep0
Oct0.1
Nov0
Dec0
012JanFebMarAprMayJunJulAugSepOctNovDecOZONE SEASON012JFMAMJJASONDOZONE
Fine particles (smoke, soot)Dust (coarse particles)Ozone (smog)Bars stack in that order, from the bottom.
See the numbers by month
Average bad-air days a year in each month in Cochise County, from 10 years of daily readings
MonthOzoneFine particlesDustAll
January000.30.3
February000.10.1
March0000
April0.200.20.4
May0.500.10.6
June0.400.10.5
July0.600.10.7
August0.2000.2
September0000
October000.10.1
November0000
December0000

The worst day since 2016 was January 8, 2025: AQI 328, from dust and coarse particles.

What causes it

The pollutant that pushed the AQI over 100 on each of the 29 bad-air days since 2016.

66%ozone
66%Ozone: smog that forms in sunlight on hot days
34%Dust: coarse particles blown up by wind

Most bad days here are ozone days: smog that builds on hot, sunny afternoons.

CDC estimates by month, 2001 to 2022

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.

January: 0.1 smoky days a yearJFMarch: 0.0 ozone days a yearMApril: 0.2 ozone days a yearAMay: 0.8 ozone days a yearMJune: 0.8 ozone days a yearJJuly: 0.5 ozone days a yearJAugust: 0.2 ozone days a yearASONDbad daysby month
See the numbers by month
CDC estimated bad-air days a year in each month in Cochise County, 2001 to 2022
MonthFine particlesOzone
January0.10
February00
March00
April00.2
May00.8
June00.8
July00.5
August00.2
September00
October00
November00
December00

What helps in Cochise County

Most bad days here are ozone, which builds on hot afternoons. Timing helps most; filters don't remove ozone.

Move workouts to the morning

Ozone peaks on hot, sunny afternoons. Mornings are usually cleaner.

Ozone guide →

Check tomorrow's forecast

AirNow posts an air quality forecast by ZIP code, usually the day before.

AirNow →

Keep one room clean on smoky days

Shut the windows and run an air purifier sized for the room.

Choosing a purifier →

For today's reading and tomorrow's forecast, check AirNow by ZIP code. Its fire and smoke map adds smoke plumes.

Purifiers with a verified smoke rating

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.

Bedroom or small room

Levoit Vital 100S-P

143 smoke CADR

Everyday
up to 222 sq ft
Heavy smoke
up to 143 sq ft
Filters
about $40 a year

The cheapest unit we found with a verified smoke rating. Enough for a bedroom clean room.

$119.99 at Levoit
Best value for smoke

Levoit Vital 200S-P

250 smoke CADR

Everyday
up to 388 sq ft
Heavy smoke
up to 250 sq ft
Filters
about $50 a year

The most verified smoke cleaning per dollar of any qualifying model: 75% more than the 100S-P for $50 more.

$169.99 at Levoit
Living room or open floor

Levoit Core 600S-P

391 smoke CADR

Everyday
up to 606 sq ft
Heavy smoke
up to 391 sq ft
Filters
$60 to $120 a year

For a big room or a small apartment. Buy the LAP-C601S-WUS version, which CARB lists as mechanical.

$299.99 at Levoit

Why 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

Every year since 2000

Bad-air days each year. The striped part is days unhealthy for everyone, over AQI 150. The worst recent year was 2024, with 13 bad-air days.

0510152000200520102015202013202540510152000201020201320254
Unhealthy for sensitive groups (101 to 150)Unhealthy or worse (over 150)
See the numbers by year
Bad-air days each year in Cochise County
YearBad-air daysOver 150
200060
200100
200250
200370
200430
200540
200690
200710
200830
200910
201040
2011110
201290
201370
201450
201500
201620
201720
201800
201900
202020
202120
202210
202330
2024132
202542

Cochise County and its neighbors

Bad-air days a year, 2021 to 2025. Arizona counties with monitors averaged about 67 bad-air days a year, weighted by population.

Pima County11
Cochise County5
Santa Cruz County3

Nearest counties with a full report: Maricopa County, AZ (100 bad-air days a year), Pinal County, AZ (48 bad-air days a year).

Questions people ask about air in Cochise County

How often is the air bad in Cochise County?

From 2021 to 2025, monitors in Cochise County recorded about 5 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 2024, with 13 bad-air days.

What causes bad air in Cochise County?

Most bad days here are ozone days: smog that builds on hot, sunny afternoons. Bad days cluster in May, June and July.

Where can I see today's air quality in Cochise County?

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 Cochise County is about 45, which is good, fine for everyone. Check it most in May, June and July, when bad days here cluster.

About these numbers

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 Cochise County almost no high-particle days and about 1 high-ozone day 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.