Quick answer: The worst has passed. After New York City's air quality index topped 230 — "Very Unhealthy," its highest reading in three years — on Thursday night, a weak front and weekend rain have pushed the Canadian wildfire smoke back to the south. NYC readings fell into the Moderate range on Friday and Saturday (dropping near an AQI of 68 at one point), and thunderstorms moving through today are scrubbing more of the fine particles from the air. It is not fully over: roughly 850 fires are still burning in Canada, most in Ontario, so a lighter round of haze could drift back early next week. But for most of the Northeast, this smoke event is winding down.
This is the July 18 follow-up to our Northeast air quality tracker. Readings still move hour to hour, so check AirNow.gov for your exact location. Here's where things stand and what to do with the tail end of a smoke event.
Where the air stands today
Thursday night was the peak. NYC's AQI climbed past 230 — deep in the "Very Unhealthy" band and the city's worst air in three years — while Chicago and parts of the Upper Midwest touched "Hazardous." Then the pattern broke. A weak front nudged the smoke south, and by Friday morning the metro area had eased from "Unhealthy" toward "Moderate," with one NYC monitor reading an AQI of 68. Saturday's showers and thunderstorms are doing the heavy lifting today, washing PM2.5 out of the air the way only rain can. If you want the health context behind those numbers, we broke it down in what an AQI of 171 actually means for your body.
One note for the weekend: the same storms that clear the smoke bring their own risk — the NYC area is under a threat for strong storms this weekend. Clearer air, but keep an eye on the sky.
Did the smoke actually clear, or just move?
Both. Rain removes particles from the air directly, and the shift in the weather pattern is steering the plume away from the eastern Northeast. That's the good news. The honest caveat: the fires that caused this haven't stopped. As of this week roughly 850 wildfires were still active across Canada, more than 180 of them in Ontario and over a hundred rated out of control. As long as they burn, the wind decides where the smoke goes. Forecasters see a chance of a lighter smoke round drifting back into the Midwest and Northeast early next week — nothing like Thursday's peak, but worth watching.
What this week taught us
Smoke events now arrive fast and without much warning. The people who rode this one out most comfortably had two things ready before the haze rolled in: a good filter already in the furnace, and a spare on the shelf. When the AQI jumped overnight, they set the thermostat fan to "On" and let the system clean the house — no scramble, no sold-out shelves. That's the whole lesson. You can't control the outdoor number, but a MERV 13 filter running on a continuous fan quietly pulls the majority of PM2.5 out of every room your system serves.
What to do as it clears
- Check the filter you ran all week. Heavy smoke loads a filter fast. If you had a 1-inch filter working through the peak, it may be dirtier than a normal month — a clogged filter chokes airflow, so look at it and swap if it's loaded. See air filters vs wildfire smoke.
- Keep the fan running a little longer. Even as the outdoor number drops, running the HVAC fan on "On" for another day clears the particles that settled inside during the event.
- Air out once it's genuinely clear. When AirNow shows Good/Moderate and the rain has passed, opening windows briefly helps flush any lingering indoor smoke smell. A carbon filter handles the odor that particle filters can't.
- Restock now, not during the next alert. The calm between events is the time to put a spare filter on the shelf. Shipping is the same on 1, 2 or 3 packs, so it costs nothing extra to keep one in reserve.
Keep on hand for the next one
For whole-home smoke defense, MERV 13 is the floor; MERV 14–16 pulls ahead in the fine-particle band if your system can handle the airflow. Our Maximum Protection collection carries MERV 13 through 16, including carbon-layer options for smoke and odor. Not sure of your size? The filter finder takes three clicks. Stocking one spare now means the next smoke day is a filter change, not an emergency.
Frequently asked questions
Is the wildfire smoke over the Northeast gone? For most areas, the worst has cleared — NYC and much of the Northeast are back in the Moderate range after Thursday's "Very Unhealthy" peak, and weekend rain is scrubbing the air. Because the Canadian fires are still burning, a lighter round of haze could return early next week, so keep checking AirNow.
Can I open my windows again? Once AirNow shows Good or Moderate at your location and the rain has moved through, yes — a brief airing-out helps clear any indoor smoke smell. If the number climbs again, close up and run the fan with a MERV 13 filter.
Should I change my filter after a smoke event? Check it. A filter that worked through heavy smoke can load up in days rather than weeks, and a clogged filter restricts airflow. If it looks gray and loaded, swap it.
What should I keep on hand for the next one? A spare MERV 13 (or higher) filter in your size, so a sudden air quality alert means a five-minute filter change instead of a run to a sold-out store.
This is general information, not medical advice — if you have a heart or lung condition and your symptoms linger after the air clears, contact your doctor or local health guidance. Ironside makes American-made air filters in every standard size, MERV 6 to 16, shipped flat-rate nationwide — the same shipping on 1, 2 or 3 packs. Find your size and breathe better.