- Northern Idaho (e.g., Coeur d'Alene, Sandpoint): Second half of October
- Central Idaho (e.g., Boise, Idaho Falls): Late October to early November
- Southern Idaho (e.g., Twin Falls, Pocatello): Late November to early December
However, it's essential to note that weather patterns can be unpredictable, and the actual start of snowfall can vary from year to year. For the most up-to-date information, it's recommended to check local weather forecasts.