Yes, snow can cancel flights. Extreme weather conditions, especially those that include snow, make navigation and landing unsafe. Airports may close due to the severe weather and roads may be blocked with snow and ice, making it difficult for crews and passengers to make it to the airport. Runways and taxiways can also become dangerous to maneuver when coated in ice and snow. Ultimately, it is up to the airline and/or airport to decide if a flight is canceled due to weather conditions.