Weather along the route is typical of Massachusetts and southern New Hampshire, with slightly warmer temperatures in the Connecticut River Valley versus the upland plateau to the east. Conditions on exposed hill tops and summits may be harsher during cold or stormy weather. Weather atop the exposed and isolated summit of Mount Monadnock can be much more severe than conditions below; high winds are common year round and winter storms on the summit can be life-threatening. Lightning is a hazard on exposed peaks and ledges during thunderstorms. High flooding is common during rainy periods on the portions of trail that dip into the Connecticut River Valley and the Westfield River Valley, sometimes obliterating the trail. The Westfield River can be forded only during dry periods, and even then not without risk. The Connecticut River is not fordable; the trail terminates where it meets it (one must walk or drive to the Northampton Route 9 bridge or arrange for boat passage to the opposite bank). Snow is common in the winter and may necessitate the use of cross country skis or snowshoes. Ice can form on exposed ledges and summits, making hiking dangerous without special equipment. Snow and ice tend to linger on Mount Monadnock well into the spring.