The moment a wildfire starts near you, you'll get an instant alert and simple tips to reduce your smoke exposure.
30xSmaller than a human hair
Fine enough to reach deep into the lungs. A MERV 13 is built to capture it.
It Doesn't Stay Local
Smoke rides the wind far downwind — you can get smoky air with no fire nearby.
Simple steps to reduce indoor exposure.
During smoke events, the EPA recommends upgrading to a MERV 13 filter — or the highest-rated filter your system can handle — to help reduce the fine particles smoke brings indoors. MERV 13 is the level most home HVAC systems can run while still capturing PM2.5, the fine particulate that makes up the bulk of wildfire smoke.
Over 70,000 wildfires burn in the U.S. every year.
Wildfire smoke can travel 1,000+ miles, affecting states that aren't even near the blaze.
Exposure to wildfire smoke can worsen asthma, trigger heart issues, and lead to ER visits.
Indoor air can hold more fine particles during wildfire events unless it's properly filtered.
The EPA advises using MERV 13 filters or portable HEPA air cleaners during wildfire smoke events.
Use the live wildfire smoke tracker and upgrade your air filters today to protect your lungs and your home.
Shop Filters For Smoke Protection
Author: Michelle Wan | filterbuy.com/author/michelle-wan/
Reviewed by: David Clark, Licensed HVAC Technician
Published: July 28, 2026
Updated: July 28, 2026
The map above is live. It shows where fires are burning near Irvine, where smoke is drifting, and what the air reads at monitors nearest your ZIP code. Read the dot closest to your house before the nearest flame icon.
What most maps will not tell you: in Irvine, the wind is a better early warning than the map. When Santa Ana winds reverse the usual onshore flow, smoke moves down the canyon corridors faster than monitors report it. By the time the sensor near Portola Springs turns orange, it is already in your hallway. Filterbuy publishes this page and a licensed HVAC technician reviews it, so it also covers the air inside your house.
The live map shows active fire locations, drifting smoke plumes, and current PM2.5 air quality near you. Irvine’s smoke usually arrives from the northeast, out of Santiago and Silverado canyons. When the map turns orange or worse, close the house, switch the thermostat fan to "On," and put a MERV 13 filter in the slot.
A red flag warning plus a canyon fire northeast of you is the trigger to close up, not the AQI number.
The U.S. EPA recommends a MERV 13 or higher HVAC filter during smoky periods, and most residential systems can take one if it is replaced often.
This page is not an evacuation alert. Orders come from the Orange County Fire Authority and CAL FIRE.
Read the map in three passes: fire icons, then plume shading, then the colored dots. Gray or brown overlays are modeled plumes drifting on current winds. Circles are regulatory monitors, squares are neighborhood sensors. The dot nearest your house matters more than the distance to the nearest fire icon.
That is the point we correct most often. On the right, wind a fire in Riverside County hazes Northwood while the canyons east of Irvine stay clear.
Sources: AirNow (EPA and USFS), South Coast AQMD, Orange County Fire Authority. Filterbuy does not issue evacuation orders.
Orange County has no single public evacuation-zone map. Alerts arrive three ways: OCFA Active Incidents for real-time fire information, AlertOC for county calls and texts (register in advance), and the Watch Duty app. OCFA Ready, Set, Go covers what to do next.
The AQI measures outdoor air. Indoors, you get a softer version of the same number, depending on how tight the house is and what filter is running. Use it as your trigger, not your indoor result.
AQI describes outdoor air. Indoor levels depend on how tight the house is and what filter is running. Source: U.S. EPA Air Quality Index.
Irvine’s smoke comes from the northeast. Portola Springs, Orchard Hills, and Northwood sit downhill from the Santa Ana Mountains and the Cleveland National Forest. Fires that start there arrive here.
The Silverado Fire began east of Irvine on October 26, 2020, burned roughly 13,400 acres, and forced more than 90,000 Irvine and Lake Forest residents to evacuate. The Bond Fire burned about 7,375 acres in Silverado Canyon six weeks later. Santa Ana winds drove both.
Five steps, in order. The first two cost nothing and do most of the work: sealing the house keeps smoke out, and the fan pushes what got in through a filter.
Close the envelope. Shut windows and doors, and close the fresh-air intake if you have one.
Switch the thermostat fan from "Auto" to "On." On "Auto," the blower runs only when heating or cooling, which in mild Irvine weather can be minutes an hour.
Put a Filterbuy MERV 13 filter in the slot. See our guide to MERV ratings if you are unsure what the scale means.
Add a portable HEPA cleaner to one bedroom. See the EPA on a cleaner air room and the CARB list for ozone-free units.
Check the filter every two weeks during active smoke, not on the calendar. Replace it when the media darkens.
MERV 13 is the answer for most Irvine homes. Wildfire smoke is mostly PM2.5, and MERV 13 is the highest efficiency a typical residential blower can handle. EPA guidance indicates a high-efficiency filter with the fan running continuously may cut indoor PM2.5 by about 50 percent, against roughly 24 percent for a low-efficiency filter (Fisk and Chan, 2017).
Two limits:
No pleated filter removes smoke gases or odors. For lingering smell, you need carbon media: Odor Eliminator filters.
Some older systems cannot handle MERV 13. If yours predates about 2000, check the manual. MERV 11 in a system that breathes well beats MERV 13 in one that is choking. Our wildfire smoke filter guide covers how to check.
We have built filters in the USA since 2013, so our view of a smoke event is the used filter that comes out afterward. Filterbuy makes 600+ sizes plus custom cuts; auto-delivery keeps spares on hand.
Three things work even when the HVAC is not yours. Most smoke guides assume a reachable filter slot, but Census American Community Survey estimates put Irvine’s renter-occupied share at roughly 55 percent.
Build one clean room instead of a clean house. A portable HEPA cleaner in the bedroom protects the eight hours you cannot avoid breathing.
Seal the entry door and the sleeve around any window or wall AC unit, which leaks more than the windows in newer Irvine construction, and close its fresh-air lever.
Ask your property manager when the return filter was last changed and what size it takes. If the return is reachable, you may be able to upgrade it yourself.
Filterbuy makes HVAC filters, not portable air cleaners, so on the first point we are pointing you somewhere we do not sell.
Wait until the map returns to green and holds for a full day. Indoor air recovers more slowly, because particles that got in must be filtered out, not blown away.
Do not reopen at night because it is cooler. Overnight inversions settle smoke back toward ground level, which is why evening readings climb after an afternoon that looked like recovery.
Change the filter after the event, not during it. A smoke-loaded filter works, but it is finished.
By the time someone calls us about smoke smell indoors, their filter has usually been loading for a day already. In Irvine, the wind tells you before the map does, and that gap is the entire window you get to close up the house.
David Clark, Licensed HVAC Technician, Filterbuy HVAC Solutions
Ordered the way smoke reaches Irvine: wind, fire, air, then your house.
Red flag warnings. The earliest signal, issued by NWS San Diego for Inland Orange County. forecast.weather.gov
CAL FIRE Incidents. Every California wildfire 10 acres or larger, with containment. fire.ca.gov/incidents
OCFA Active Incidents. Local authority for the canyons northeast of Irvine and evacuation orders. ocfa.org
AirNow Fire and Smoke Map. Built for smoke events: fires, plumes, and hourly PM2.5. fire.airnow.gov
South Coast AQMD. AQI at 1,218 locations, so you see your neighborhood, not a county average. aqmd.gov
EPA cleaner air room guide. How to seal and filter one room. epa.gov
CARB certified air cleaners. Purifiers tested to emit little or no ozone. ww2.arb.ca.gov
~50% — indoor PM2.5 reduction with a high-efficiency filter and the fan running continuously
~24% — the same setup with a typical low-efficiency filter
Source: U.S. EPA, Strategies to Reduce Exposure Indoors, citing Fisk and Chan (2017)
South Coast AQMD reports AQI at 1,218 separate locations across its jurisdiction
Source: South Coast AQMD, Current Air Quality Data
44% of Americans live in counties with failing grades for ozone or particle pollution
Check the AQI nearest you on the live map. At 101 to 150, people with asthma, heart or lung conditions, children, and older adults should limit outdoor exertion. At 151 and above, everyone should.
Indoor air lags outdoor air. EPA reports indoor PM2.5 typically runs 55 to 60 percent of outdoor levels with windows closed, ranging 30 to 100 percent across homes. Particles already inside must be filtered out, not blown away.
Only if they seal. EPA advises that an N95 reduces fine-particle exposure when it fits snugly with no gaps, and that dust masks and bandanas do not. They come in no children’s sizes, and children under 2 should not wear one.
No. CARB guidance is explicit that swamp coolers and whole-house fans should not run during wildfire smoke. Both pull unfiltered outdoor air into the house.
No. EPA advises against candles, incense, and gas, propane, or wood-burning stoves and fireplaces during a smoke event. Skip frying and broiling, and do not vacuum without a HEPA filter.
Irvine homeowners who stay ahead of smoke season have the filter in the slot before the map turns orange. Find your size and get a MERV 13 shipped factory-direct from Filterbuy, free, before the next Santa Ana.
Written by Michelle Wan, Brand Manager and Air Quality Writer at Filterbuy, covering AQI and wildfire smoke.
Reviewed for technical accuracy by David Clark, Licensed HVAC Technician and owner of Filterbuy HVAC Solutions, with 10+ years of field experience. David checked the claims on MERV ratings, airflow, and filter compatibility.
AQI: The EPA’s color-coded 0 to 500 air quality scale. Higher numbers mean greater health concern.
PM2.5: Fine particulate matter 2.5 microns or smaller, the primary pollutant in wildfire smoke.
Santa Ana winds: Hot, dry offshore winds flowing from the interior deserts toward the coast, most common October through December, and the main driver of Orange County wildfires.
South Coast AQMD: The air pollution agency responsible for Orange County, including Irvine.
Filterbuy: An American manufacturer producing pleated HVAC filters in the United States since 2013, in 600+ sizes plus custom cuts, shipped factory-direct.
Subscribe to wildfire smoke alerts for Irvine, CA, to get a heads-up before the next event reaches your area.
