Wildfire smoke from Alberta is moving back into Montana. A weak cold front is about to cross the border, and there’s just enough of a northwest flow to transport smoke into the state tonight. Air quality will likely drop to at least “Moderate” with a few locations “Unhealthy for Sensitive Groups”. People with respiratory issues and heart disease should avoid exerting themselves outside. Enough of a west wind will develop on Tuesday to improve air quality slowly through the day.