The best time to go to Merrimack, New Hampshire, is during the summer months, from June to August, or in the fall, from September to October.Summer in Merrimack offers pleasant weather, with average temperatures in the 70s Fahrenheit, making it ideal for outdoor activities. Families will appreciate the opportunity to visit attractions like the Anheuser-Busch Brewery (known for its Clydesdales) or explore the Grinell Wildlife Sanctuary. Many local farms also offer pick-your-own fruit experiences during this time.For couples or travelers who appreciate scenic beauty, the fall foliage season from September to October is spectacular. The rolling hills surrounding Merrimack transform into a vibrant display of red, orange, and gold.