Meridian, Idaho Air Quality
Meridian air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now
Meridian, ID · Air quality right now
The air quality index in Meridian, ID is 148 (Unhealthy for Sensitive Groups) right now — a concern for sensitive groups.
Is it safe to be outside in Meridian today?
Use caution — Unhealthy for Sensitive Groups (AQI 148)
Sensitive groups — asthma, heart conditions, kids, older adults — should limit prolonged exertion.Main pollutant: PM2.5
Pollutants right now
- PM2.538 µg/m³Main pollutantfine particles — smoke, exhaust, soot
- PM1040 µg/m³coarse particles — dust, pollen, ash
- Ozone113 µg/m³smog — builds on hot, sunny days
- NO₂3.3 µg/m³nitrogen dioxide — traffic, combustion
ExerciseSensitive groups should shorten or move workouts indoors; others are fine.
Wildfire smoke & fire weather in Meridian
Smoke checkFine-particle (PM2.5) level right now: 38 µg/m³ Unhealthy for Sensitive Groups on the EPA PM2.5 scale. PM2.5-based; smoke is one possible source — traffic, industry, and dust raise the same number.
Wildfire smoke shows up in air-quality data as fine-particle (PM2.5) pollution — it’s the number that climbs when smoke moves in. A Fire Weather Watch from the National Weather Service means critical fire-weather conditions — dry fuels, low humidity, gusty wind — are possible in the next day or two; a Red Flag Warning means they’re happening or imminent. On smoky days, EPA and AirNow guidance is to limit time outdoors, keep windows closed, run filtration if you have it, and wear an N95 if you must be outside. See where smoke and storms sit right now on the live weather map.
Cleaner-air gear
- Levoit Core 300S True-HEPA Air Purifier
A true-HEPA purifier captures the PM2.5 that drives most bad-air days — wildfire smoke, traffic, smog. Run it in the room you sleep or work in; the air you breathe for hours matters most.
- 3M Aura N95 Respirator Masks (20-pack)
A well-fitted N95 filters the fine particles cloth and surgical masks miss — the right protection for going outdoors on a smoky or Unhealthy-AQI day.
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How to read Meridian’s air quality
Air quality is reported as the EPA Air Quality Index (AQI), a 0–500 scale set by whichever pollutant is worst at the moment — where an AQI under 100 is a safe day for outdoor activity in Meridian and above 100 people with asthma, heart conditions, the very young, and older adults should start to scale back.
For the full six-category scale — every band, its color, and the pollutants behind the number — see the AQI scale guide.
Air quality over time in Meridian
Across the EPA’s county records from 2020 to 2025, Meridian’s cleanest year was 2025 (median AQI 42) and its most polluted was 2022 (median AQI 48); the typical (median) day has trended cleaner since 2020.
| Year | Median AQI | Good | Moderate | USG | Unhealthy+ | Main pollutant |
|---|---|---|---|---|---|---|
| 2020 | 44 | 242 | 106 | 11 | 7 | PM2.5 |
| 2021 | 46 | 223 | 124 | 15 | 3 | Ozone |
| 2022 | 48 | 196 | 162 | 6 | 1 | Ozone |
| 2023 | 44 | 251 | 111 | 3 | 0 | Ozone |
| 2024 | 44 | 230 | 101 | 28 | 7 | Ozone |
| 2025 | 42 | 270 | 95 | 0 | 0 | Ozone |
“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 2020–2025.
Frequently asked
- Why is the air quality bad in Meridian today?
- Poor air quality in Meridian is usually driven by one dominant pollutant — most often fine particle pollution (PM2.5) from wildfire smoke, vehicle exhaust, or industry, or ground-level ozone (smog) that builds on hot, sunny, stagnant days. The AQI at the top of this page names which pollutant is highest right now; that pollutant is what's making the air "bad," and weather — heat, calm wind, or smoke blown in from elsewhere — is usually why it spikes on a given day.
- Is it safe to exercise outside in Meridian right now?
- It depends on the AQI. Below 100 (Good or Moderate) it's generally fine to run or work out outdoors. From 101–150 (Unhealthy for Sensitive Groups), people with asthma, heart conditions, kids, and older adults should shorten or move workouts indoors. At 151+ (Unhealthy) everyone should cut back on hard outdoor exertion, because exercise makes you breathe more polluted air deeper into your lungs. The live verdict at the top of this page gives the go/no-go for Meridian right now.
- What's the main pollutant in Meridian's air?
- The two pollutants that most often drive Meridian's AQI are fine particulate matter (PM2.5) and ground-level ozone. PM2.5 tends to dominate in winter, near traffic and industry, and during wildfire smoke events; ozone tends to dominate on hot, sunny summer afternoons. This page identifies the dominant pollutant live — it's the one whose sub-index matches the overall AQI — so you can see which is the problem today rather than guessing by season.
More for Meridian
See the full Meridian, ID weather forecast — hour-by-hour outlook, NOAA radar, satellite, and air quality.