Smoke forecast
Where the smoke over Philadelphia was, and where the model sends it next. Scrub back 12 hours or forward 48. Every hour shown is a model estimate, not a measurement.
The scale is anchored to visibility, because that is the one reading you can take yourself without trusting a model. Distances are approximate.
From Belmont Plateau the Center City skyline is sharp about four miles southeast, and the towers read individually against a clean sky.
The skyline still reads from Belmont Plateau but has gone flat, and the buildings behind Comcast have lost their separation.
From the Art Museum steps the Comcast towers hold a mile and a half off, while City Hall and the buildings around it soften.
From the Camden waterfront the near Center City towers hold across the river, a mile out, while the tops start to disappear.
The crown of the Comcast Technology Center goes. From the Schuylkill banks you can lose Center City entirely.
Philadelphia takes Canadian smoke on the same northerly flow that brings it to New York and Boston, arriving from Quebec and Ontario after a day or more in transit. The city's own summer haze from humidity and ozone is a separate thing, which is why hazy days here are not automatically smoke days and the source matters.
June 2023 is the local marker, when Quebec smoke pushed Philadelphia into the worst air quality category and the skyline went orange-brown for parts of two days.
Most hazy summer days in Philadelphia are humidity, not smoke. Mid-Atlantic moisture scatters light the same way fine particles do, which flattens the skyline and softens the horizon on a perfectly clean air day. The tell is colour and smell: humid haze stays white or blue-grey and smells like nothing. Smoke goes yellow-brown at the horizon and you can smell it before you can see it.
The verdict at the top of this page answers that for Philadelphia specifically, and in this city it is worth reading against your own eyes rather than instead of them. Most hazy summer days here are Mid-Atlantic humidity rather than smoke, so the verdict can read All clear on an afternoon when the skyline has genuinely flattened. The section above on what is not smoke gives you the tell. Everything shown is a model estimate rather than a measurement at your address.
That is the headline answer above: the clear time, the first stretch of at least six straight hours below the Hazy threshold. It is a smoke clear time and nothing else. Humid haze runs on its own schedule and a muggy Philadelphia afternoon can stay soft for a week regardless of what this page says, because moisture scatters light the same way fine particles do without being fine particles.
The question splits in two here more than on most pages. If the horizon is white or blue-grey and smells like nothing, that is humidity and ozone, and it is a local Mid-Atlantic summer problem. If the horizon is yellow-brown and you could smell it before you saw it, that is Quebec or Ontario smoke on northerly flow after a day or more in transit, which is what June 2023 was, when the skyline went orange-brown for parts of two days.
Quebec and Ontario, on the same northerly flow that brings it to New York and Boston, arriving after a day or more aloft. New York usually sits under it first, and on northwesterly setups Pittsburgh gets it earlier still and holds it in the river valleys, and both are linked below. Run the timeline backward on the map and the smoke path is visible, which is the fastest way to separate a smoke day from a humid one.
The five-day strip above gives the day-by-day read and the timeline covers forty-eight hours hour by hour. If the current haze is humidity rather than smoke, this page is the wrong instrument for the question and a plain weather forecast is the right one. The strip will happily show clean air behind a sky that stays soft. Smoke forecasts are sharpest one to two days out and the page shows the spread.
Belmont Plateau is the far vantage: about four miles to Center City, with the towers reading individually against a clean sky. When the buildings behind Comcast lose their separation, something is in the air. Then the Comcast towers from the Art Museum steps, then the crown of the Comcast Technology Center. But check colour at every step: white or blue-grey is water, yellow-brown at the horizon is smoke.
Where Philadelphia's smoke usually shows up first, and the places that share its air.
The Quebec plumes that reach Philadelphia arrive on the same northerly flow that crosses the New York metro first.
On northwesterly setups the Ontario smoke crosses the state and sits in the Pittsburgh river valleys before it reaches the Delaware.
Most smoke in the eastern half of the continent is Canadian, and it is old by the time it arrives.
Smokeshow is for informational and educational purposes only. It is not health, medical, or safety advice. Forecasts are model estimates and can be wrong, sometimes by a lot. Descriptions of what you might smell, see, or feel are generalizations, not predictions about your body. For decisions about your health, outdoor activity, or air quality safety, rely on official sources like AirNow.gov, the National Weather Service, and your local health authorities, and talk to a medical professional about your own situation.