Prepare for all types of weather when you visit North Dakota. The trail is open for use all year, but at various times of the year, the trail may be impassable due to snow, ice, high water, and mud. Please don't use the trail when wet! Doing so can cause permanent damage to the trail. Users of the Maah Daah Hey Trail system share the same space with horseback riders, hikers, and bicyclists. Shared-use trails are successful when users cooperate and abide by the rules.
Some of the best months of the year to visit are mid-June through September. May and early June are the greenest months but can be rainy which leads to off-days.
You can check the NDAWN weather sites that provide weather data from automated weather stations located near these towns closest to the MDH: Beach, Dickinson, Watford City. Other towns to check are Grassy Butte, Medora and Theodore Roosevelt National Park.