AQI Basics for Movers: Air Quality at Your New Address

The AQI — the EPA's Air Quality Index — runs from 0 to 500, and the line that matters for moving day is 150: above it, the air is unhealthy for everyone, not just sensitive groups, and a move means six-plus hours of heavy exertion in it. You can check the current and forecast AQI for any US ZIP code at airnow.gov, and it's worth learning your new region's bad-air season before you unpack.

The scale has six color bands: 0–50 is Good (green); 51–100 Moderate (yellow); 101–150 Unhealthy for Sensitive Groups (orange); 151–200 Unhealthy (red); 201–300 Very Unhealthy (purple); and 301+ Hazardous (maroon). The index converts measured pollutant concentrations onto one common scale, and whichever pollutant is worst that day sets the number you see.

In practice two pollutants drive almost every bad-air day. PM2.5 is particulate matter under 2.5 microns — smoke, exhaust, fine dust — small enough to travel deep into the lungs; wildfire smoke is overwhelmingly a PM2.5 event. Ground-level ozone forms when sunlight cooks vehicle and industrial emissions, which makes it a hot-summer-afternoon problem. The distinction matters for what you do: ozone stays largely outdoors and drops off indoors, while smoke infiltrates buildings and follows you inside.

Bad-air seasons are regional, which matters if your move crosses the country. Western wildfire smoke runs roughly mid-summer through fall, varying a lot year to year — and smoke travels continental distances; in June 2023, Canadian wildfire smoke pushed New York City to some of its worst readings on record. Valley cities like Salt Lake City and Fairbanks get winter inversions that trap PM2.5 for days, and hot metros like Phoenix, Denver, and Los Angeles get summer ozone. Move from Boston to Boise and your bad-air season shifts from basically never to August.

Know where the number comes from, because it shapes how much to trust it. AQI readings come from regulatory monitoring stations, and the nearest one may be miles from your address — the reading describes your airshed, not your block. During smoke events, the AirNow Fire and Smoke Map layers in low-cost sensors for finer-grained, street-level texture. AirNow also distinguishes the NowCast (conditions right now) from the next-day forecast; for planning a move, the forecast is the one you want.

The moving-day playbook scales with the number. Heavy exertion means you're breathing far more air per hour than at rest, so the thresholds bite earlier than they would on a normal day. At 101–150, build in breaks and keep anyone with asthma or heart conditions on indoor duty. At 151+, get N95 respirators — they actually filter PM2.5, which loose cloth and surgical masks largely don't — shift the heavy lifting to morning, keep the house and truck closed up between loads, and run vehicle ventilation on recirculate. And remember that box dust and disturbed attic insulation add their own particles regardless of what's outside.

Once you're in the new home, the first-week checklist is short. Check the HVAC filter and upgrade to MERV 13 if the system supports it — MERV is a filter efficiency rating, and higher numbers capture finer particles, including smoke. Sign up for AirNow's email alerts for the new ZIP. If you've landed in a smoke-prone region, buy a portable HEPA purifier for the bedroom and a stash of N95s before the season starts, not during it, when supplies tend to run short.

If you're still choosing where to live, historical context helps more than a single reading: AirNow and EPA's AirData publish past conditions, and one smoky week doesn't define a year. LocateFlow's New Home Dossier includes EPA air quality context for a new address alongside its FEMA and NWS layers — area-level data, so treat it as a description of the region's air, not your specific street.

First, check the AQI forecast at airnow.gov for moving day at both addresses. Second, above 100, schedule the heavy lifting early and plan breaks; above 150, use N95s and shorten outdoor exposure. Third, on arrival, check the HVAC filter and upgrade to MERV 13 where the system allows. Fourth, sign up for air quality alerts for the new ZIP code. Fifth, learn the local bad-air season and stock purifier filters and masks before it begins.