The summer heat that’s baked much of Iowa during the past few months could mean the colorful signs of autumn will arrive early this year. Iowa State University forestry professor Paul Wray says a few trees are beginning to show signs of fall’s arrival in yellow, gold, brown, orange and red.Cottonwoods are already showing some color. Oaks may see an improved color due to the dry weather, while the maples may be more dull. Since Labor Day is now behind us and the nighttime temperatures are already dipping into the 50s, Wray says people will soon be planning their weekends around leaf-watching trips.Hot, dry conditions can put foliage under stress, which could lead trees to shut down as soon as possible in preparation for winter. Wray says the many types of trees behave differently.Professor Wray says the fall color show should be “average” in Iowa, with dull and bright spots of color scattered around the region. There is a hotline Iowans can call for fall color updates: (515) 233-4110.