The best time to go to Grantham, New Hampshire, depends on whether you prefer winter sports or warmer weather activities.For those looking for winter sports, the period from December to March is ideal. This is when the area typically receives reliable snowfall, making it superb for skiing, snowboarding, and snowshoeing. The nearby mountains offer excellent slopes, and many accommodations provide easy access to winter recreation.If you prefer warmer weather and outdoor adventures, the summer months from June to September are wonderful. During this time, the weather is pleasant for hiking, golfing, and exploring the natural beauty of the region.