Local gardeners hoping for a few more tomatoes or zucchinis should plan to cover their crops this weekend, with a cold plunge on the way.

Temperatures across Western Montana are forecast to drop into the 20s and 30s beginning Sunday night, according to the National Weather Service in Missoula. Widespread frost and freezing conditions are expected through Tuesday morning.

The Weather Service said the shift signals the end of the growing season for the region. Gardeners are advised to cover or harvest any remaining sensitive vegetables or flowers and bring potted plants indoors. It’s also a good time to winterize homes and blow out irrigation systems.

Daytime highs are expected to reach only into the 50s.

Mountain areas are likely to see their first snowfall of the season. Locations in Glacier National Park and along the Continental Divide above 7,000 feet have an 80% chance of at least 2 inches of snow, with a 50% chance of 6 inches or more. Snow levels could drop to 5,000 feet in some areas.

Gusty winds of up to 25 mph are also expected, creating raw conditions for backcountry hunters and hikers.

“In general, people in most mountain locations above 6,000 feet should prepare for winter-like conditions, including in the Bitterroot, Sapphire, Anaconda-Pintler, Flint Creek, Swan, Mission and Rattlesnake ranges,” the weather service said in its Thursday forecast.