The best time to visit Monticello, Minnesota, is during the summer months, from June to August, or in the early fall, during September and October.Summer in Monticello offers the warmest weather, with average temperatures in the 70s Fahrenheit, making it ideal for outdoor activities. The Mississippi River is a focal point during this time, with opportunities for boating, fishing, and enjoying the riverfront parks. Families will appreciate the chance to explore the local parks and recreation areas, such as Lake Maria State Park, which offers hiking and wildlife viewing.Early fall provides comfortable temperatures, typically in the 50s and 60s Fahrenheit, along with the scenic beauty of changing leaves. This season is great for couples seeking a peaceful getaway and picturesque drives through the countryside.