Air quality warnings are in effect, stretching from Windsor through London east to Toronto. “Some of the poorest air quality in the world right now in and around the GTA,” said meteorologist Julie Atchison. “Smoke from fires in northwestern Ontario continuing to blow towards southern Ontario. So yesterday areas like Barrie, Muskoka, Peterborough had very poor air quality. That’s now sinking southward as we take a look at the air quality readings.” In and around the greater Toronto area, there is extreme high risk above 10, London still in the moderate risk category, but in Grand Bend air quality is now poor, towards Tiverton, extreme risk. “Anyone with breathing issues, the very young and elderly also severely affected when the air quality drops like this, temperatures across the region on the very warm side. We’re still under the heat warning, but likely that smoke will start to keep a lot of those temperatures at bay through the afternoon,” Atchison added. Warmth holds overnight anywhere between 18 and 22 degrees with smoke in the forecast for Thursday as well. “The forecast high 30 degrees. I will be surprised if we make it to 30 degrees, especially as that smoke starts to settle in,” said Atchison. Here’s a full look at the forecast Wednesday: Mainly cloudy. 30 per cent chance of showers this afternoon with risk of a thunderstorm. Widespread smoke. Wind northwest 20 km/h. High 31. Humidex 40. UV index 9 or very high. Wednesday evening: Partly cloudy. 30 per cent chance of showers early this evening with risk of a thunderstorm. Widespread smoke. Wind northwest 20 km/h becoming light this evening. Low 20. Thursday: Widespread smoke. Wind becoming northwest 20 km/h near noon. High 30. Humidex 33. UV index 9 or very high. Friday: A mix of sun and cloud with 30 percent chance of showers. High 29. Saturday: Cloudy with 60 per cent chance of showers. High 29. Sunday: A mix of sun and cloud. High 27.