The best time to visit Portsmouth is during the summer months, from June to August, when the weather is warm and ideal for outdoor activities.During this period, the average daily temperatures range from the mid-60s to the low 80s Fahrenheit, making it pleasant for exploring the city's historic streets, dining al fresco, and enjoying the waterfront. You'll find a full schedule of events and festivals, like Market Square Day, which draws many visitors. The ferry services to the Isles of Shoals are also fully operational, offering scenic day trips.Another excellent time to visit is in the fall, from September to October, when the foliage is at its peak. The cooler, crisp air, with temperatures typically in the 50s and 60s, creates a picturesque setting for walks through the historic neighborhoods. While some seasonal attractions might begin to wind down, many local businesses remain open, and the crowds are generally smaller than in the summer. This time of year is particularly appealing for couples looking for a quieter, scenic getaway.