September is often the best month for backpacking, with dry, comfortable days, cool nights, and few bugs. Black flies, or mayflies, emerge by late April or early May and pester hikers until late June or early July, while mosquitoes come out in late spring and dissipate by late summer. Fall foliage colors peak anywhere from mid-September to early October. Winter sets in at higher elevations by mid-November. Summer high temps typically range from the 60s to the 80s, and lows vary from the 50s to below freezing.
Days can be humid in the forests and windy above treeline.
Snow may fall in any month at higher elevations. July and August see occasional thunderstorms, but July through September are the driest months. Timberline begins roughly where trees are less than 8 feet tall and is often indicated by trailside signs. Stay on the trail in the alpine zones to avoid damaging fragile vegetation. A WMNF parking pass is required at all WMNF trailheads, which are marked by signs.