When air quality in your area reaches unhealthy levels, we'll send you a quick alert, along with expert tips on how to reduce your exposure.
The Air Quality Index (AQI) measures how polluted the air is and how it may affect your health.
0–50 (Good): Air quality is satisfactory.
51–100 (Moderate): Acceptable, but some pollutants may pose minor concerns.
101–150 (Unhealthy for Sensitive Groups)
151–200 (Unhealthy)
201–300 (Very Unhealthy)
301+ (Hazardous)
Still okay for most, but if you have asthma or allergies, take it easy and avoid long outdoor workouts.
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By Michelle Wan, Brand Manager & Air Quality Writer · Reviewed by David Clark, Licensed HVAC Technician · Published: July 6, 2026 · Updated: July 6, 2026
You step outside in Anaheim, glance toward the San Gabriel foothills, and the horizon looks hazy. Before you send the kids to the park or head out for a run, one number tells you what you're breathing. That number is the Air Quality Index, and across Orange County it can change hour by hour, spiking when wildfire smoke drifts in.
Most of what floats through your air stays invisible, which makes it easy to take for granted. The live map below shows Anaheim's AQI right now, and the sections that follow turn that number into clear steps for your family.
The live map above shows Anaheim's current AQI, updated through the day from South Coast AQMD and EPA AirNow monitors. Anaheim usually sits in the Good to Moderate range, from 0 to 100, though summer ozone and wildfire smoke can push it higher. When the reading is at or below 100, most people can go about their day. When it climbs above 100, sensitive groups should ease up outdoors and run a MERV 13 filter indoors.
The AQI runs from 0 to 500. A reading at or below 100 is generally satisfactory, and above 100 the air turns unhealthy first for sensitive groups, then for everyone.
South Coast AQMD monitors and regulates Anaheim's air as the air district for all of Orange County, working alongside EPA AirNow.
PM2.5, the fine particle in wildfire smoke, is the pollutant most likely to spike Anaheim's AQI during fire season.
Ground-level ozone peaks on hot, sunny afternoons, so Anaheim's AQI is often higher at midday than first thing in the morning.
On days above 100, a MERV 13 filter captures far more fine smoke particles than a standard MERV 8 and helps protect the air inside your home.
The AQI turns pollutant concentrations into one number on a scale of 0 to 500, with six color-coded categories. A value of 100 lines up with the national health standard for a pollutant, so anything at or below 100 is generally satisfactory. As the number rises past 100, the health concern grows, first for sensitive groups and then for the whole population. If you want the fuller picture, our guide to what the AQI is and how it's measured walks through the scale and the pollutants behind it.
The table below pairs each AQI band with what it means for your day in Anaheim and the filter setting that keeps your indoor air ahead of the outdoor conditions.
Source: AQI ranges and health guidance follow U.S. EPA AirNow categories.
Anaheim sits in the South Coast Air Basin, where coastal mountains trap pollution against the shore and hold it in place on calm days. Traffic on freeways like the I-5 and the SR-91 feeds nitrogen oxides into the air, and summer sunlight cooks those emissions into ground-level ozone. During fire season, smoke from regional wildfires drifts in and sends PM2.5 climbing, sometimes for days at a time. A marine layer and temperature inversions can cap the basin and keep all of it near the ground. Nearby cities see the same pattern, which is why our Long Beach air quality page often tracks close to Anaheim's readings.
Read today's number against the table above. At or below 100, outdoor plans are fine for most people. Between 101 and 150, children, older adults, and anyone with asthma or heart disease should shorten hard outdoor efforts. Above 150, everyone should cut back, and above 200 the safest choice is to stay inside. For a closer look at the thresholds that matter most, our guide to which AQI levels are unsafe for sensitive groups shows who should adjust plans and when.
Indoor air follows outdoor air within hours, so the number on the map is also a signal for what to do inside. Close your windows during peak pollution and run your HVAC fan so air keeps cycling through the filter. Fit the highest-efficiency filter your system accepts. A MERV 13 filter captures the fine smoke particles a lighter filter misses. On heavy smoke days, add a portable HEPA unit in the room where your family spends the most time. When smoke forces you outdoors, our guide to N95 masks during wildfire smoke explains what actually helps.
Use the comparison below to match a filter to the air you expect.
MERV is the Minimum Efficiency Reporting Value, the industry scale for how much a filter captures. Higher numbers trap smaller particles.
After manufacturing filters for over a decade and serving more than two million households, we've seen how fast indoor air follows outdoor air. When Anaheim's AQI climbs, the families who stay comfortable are the ones who close the windows and put a high-efficiency filter to work.
David Heacock, Founder and CEO of Filterbuy
You can't protect your family from what you can't see, and most of what floats through Anaheim's air is invisible. These are the sources our air-obsessed team trusts to make it visible. Every one is a government agency or national health authority, so you're getting the straight story from the people who measure this for a living.
The EPA built the AQI so you don't need a science degree to read the air. Its team walks you through the six color bands and why 100 is the number that changes your plans in EPA AirNow's AQI Basics guide.
South Coast AQMD runs the monitors that measure the air over all of Orange County, so its data is as close to your block as it gets. Pull up the current numbers for your area on South Coast AQMD's live monitoring page.
Ever wonder how a raw pollutant reading turns into “keep the kids inside today”? The EPA shows you the reasoning behind the color-coded advice in its guide to communicating air quality.
PM2.5 is sneaky because it's small enough to reach your lungs and even your bloodstream. California's own air board spells out those health effects for Californians in CARB's particulate matter and health overview.
Children, older adults, and anyone with asthma or heart trouble feel bad air first. The CDC tells you who's most vulnerable and the simple moves that lower their exposure in its air pollutants guide.
A single number on the map connects to a worldwide health story. The World Health Organization ties outdoor air pollution to millions of premature deaths a year, and you'll find that context in its ambient air pollution fact sheet.
When you want the health facts without the jargon, a patient-advocacy voice helps. The American Lung Association breaks down particle pollution and what it does to your lungs on its particle pollution page.
We've shipped Filterbuy filters into California homes through every recent fire season, and we've watched how fast outdoor air becomes indoor air. These three federal numbers match what we see on the ground.
The stat that matters most never shows up on the map. It's the one sitting in your filter slot. After years of breaking these studies down for Filterbuy homeowners, I see the same split every smoke season. The families who stay comfortable read a rising AQI as a cue to protect the air indoors, well before they think about canceling the run.
Michelle Wan, Brand Manager and Air Quality Writer, Filterbuy
A 10 microgram-per-cubic-meter rise in wildfire PM2.5 was linked to as much as a 10% jump in respiratory hospitalizations.
The same rise in PM2.5 from other sources: up to about 1.3%.
What most people miss: it's the same amount of pollution behaving very differently depending on where it came from. Air-quality rules treat all PM2.5 alike, so this is the rare case where knowing the source changes what you do. When it's smoke, Filterbuy treats it as a MERV 13 day, every time.
Source: Aguilera et al., 2021, Nature Communications.
2024 totals: 64,897 wildfires and close to 8.9 million acres burned nationwide.
That ran above both the five-year and ten-year averages.
What we see in Anaheim: PM2.5 climbs on days when the nearest fire is a state away, and late summer through fall is when Filterbuy fields the most questions from local homeowners. Distance is no guarantee, so we tell families to stock spare filters ahead of the season.
Source: National Interagency Fire Center Wildland Fire Statistics.
Anaheim's population: 346,824 people.
Share under age 18: about 23.5%.
Why this one hits home: kids' developing lungs feel bad air first, and they're who we picture when we build a filter. A climbing number here means a lot of young lungs across a city that sits entirely under one air district.
Source: U.S. Census Bureau, Anaheim QuickFacts.
Put together, they point to a simple, local playbook we follow:
Start with the daily AQI. Smoke that hazes Anaheim's sky often begins a state away, so the number warns you before your eyes do.
Treat smoke days differently from smoggy ones. When fine particles come from fire, step up to MERV 13. On ordinary haze days, your usual filter handles it.
Protect the youngest first. With nearly a quarter of the city under 18, a climbing number is your cue to move kids' hardest play indoors until it settles.
Air Quality Index (AQI). A 0 to 500 scale from the EPA that reports how clean or polluted the air is and what it means for health.
PM2.5. Fine particles under 2.5 micrometers wide, small enough to reach deep into the lungs. They are the main pollutant in wildfire smoke.
PM10. Coarser inhalable particles up to 10 micrometers, such as dust and pollen.
Ground-Level Ozone. A gas formed when sunlight reacts with vehicle and industrial emissions. It peaks on hot, sunny afternoons.
MERV. The Minimum Efficiency Reporting Value, an industry scale for how much a filter captures. Higher numbers trap smaller particles.
HEPA. A High-Efficiency Particulate Air standard for filters that capture at least 99.97 percent of fine particles, used in portable air cleaners.
Sensitive Groups. People at higher risk from pollution, including children, older adults, and those with asthma, heart disease, or lung disease.
South Coast AQMD. The South Coast Air Quality Management District, the agency that monitors and regulates air for all of Orange County, including Anaheim.
For the mechanics of the physical media that traps these particles, see the reference article on the air filter.
Checking Anaheim's AQI takes a few seconds, and it changes how you plan a day well before you feel a scratchy throat. The habit that matters most is pairing that outdoor number with an indoor move. When the map turns orange, you close the windows and let a good filter do quiet work in the background. That is how a family stays comfortable through smoke season without hiding from Southern California life.
To see how the rest of the state is doing, our statewide California air quality map tracks every major city in one place.
Bookmark this page and check the live map before outdoor plans, especially on hot afternoons and during fire season.
Sign up for South Coast AQMD air quality alerts so you know before conditions turn.
Fit the right filter for the season. A MERV 11 filter handles everyday air, and you can step up when smoke arrives.
Seal obvious gaps around windows and doors so less outdoor air sneaks in on bad days.
A: Check the live map at the top of this page. If the AQI is at or below 100, the air is generally fine for most people. Above 100, sensitive groups should take it easier outdoors, and above 150 everyone should cut back.
A: Any AQI at or below 50 is Good, which means little to no health risk. Readings from 51 to 100 are Moderate and still acceptable for most people, though unusually sensitive individuals may notice symptoms.
A: The live map reports Anaheim's current PM2.5 alongside the overall AQI. PM2.5 is the fine particle that spikes during wildfire smoke, and it often drives the AQI on the worst air days.
A: If the AQI is at or below 100, outdoor exercise is fine for most people. Between 101 and 150, sensitive groups should shorten hard efforts. Above 150, move your workout indoors.
A: South Coast AQMD runs the monitoring network for all of Orange County, and its data feeds into EPA AirNow. Both are the authoritative sources behind the readings you see here.
A: A MERV 13 filter captures the fine PM2.5 particles in smoke far better than a standard MERV 8. On heavy smoke days, pair it with a portable HEPA unit in your main living space.
A: Haze in Anaheim is usually fine particle pollution (PM2.5). It often comes from wildfire smoke that traveled in from fires elsewhere in California, or from summer ozone and marine-layer conditions that trap pollutants in the basin. Check the live map above for the current reading.
A: Anaheim's air usually sits in the Good to Moderate range, but it can climb into unhealthy territory during wildfire smoke events and hot, high-ozone summer afternoons. The live map shows where today falls.
Anaheim's air will keep shifting with the seasons. Your indoor air does not have to. Match your system with a filter built to handle smoke and fine particles, and keep your family comfortable no matter what the map says.
