Officials warned young children and those with respiratory illnesses to take precautions. For weeks, smoke from Canadian wildfires has been drifting across the border.

New York City, Long Island and the Hudson Valley will all experience air quality within the 101-150 range on the air quality index Sunday, the state’s Department of Environmental Conservation forecasted—meaning the air could contain fine particles and could be “unhealthy for sensitive groups.”

Isolated thunderstorms are in the forecast for Sunday, followed by increasing heat and humidity Monday and Tuesday, according to the National Weather Service. Additionally, the state has issued an air quality advisory for Sunday until midnight for Long Island, as well as New York City and all the way through the upper Hudson Valley.