Guadelupe Mountains National Park
Sam Houston National Forest and Caddo Lake State Park
Reason: At this time of the year there is less rain, cooler weather, fewer insects and less poison ivy.
Seminole Canyon State Park, Lake Amistad and Judge Roy Bean Museum
Reason: The Rock Art Rendezvous Festival only happens once a year during this month. Also there is cooler weather and less crowds.
Yuca plant in bloom
Guadelupe Mountains National Park and Monohans Sandhills State Park
Reason: The weather is more temperate and the flora are just starting to bloom.
Enchanted Rock State Park and LBJ State Park
Reason: Beat the summer crowds and enjoy the temperate weather. See cactus in bloom.
Mustang Island State Park and Padre Island National Seashore
Reason: The weather is starting to heat up, so it's a great time to hit the beach.
Pedernales Falls State Park
Reason: You should expect hot weather, but there are plenty of shade trees and water holes available to cool off.
Davis Mountain State Park, Fort Davis National Historic Site, McDonald Observatory, Balmorhea State Park
Reason: The town of Fort Davis puts on a truly Americana Fourth of July celebration. The weather may be hot, but you can cool off in the spring fed pool at Balmorhea.
Colorado Bend State Park, Inks Lake State Park and Longhorn Caverns State Park
Reason: During the heat of the summer it helps to be close to cool water or cool caves.
Devil's River State Natural Area
Reason: It may be warm, but you'll be surrounded by pristine water.
Caprock Canyon State Park and Palo Duro Canyon State Park
Reason: The soft light of fall blends well with the colors of the canyon.
Lost Maples State Park, Garner State Park and Bandera
Reason: Time it right and you'll have the chance to observe the fall foliage. On any given Saturday in Bandera you will likely encounter some real cowboys walking around Main Street.
Emory Peak in Big Bend National Park
Big Bend Ranch State Park and Big Bend National Park
Reason: Not too hot, not too cold, just about ideal weather and fewer people.
That's my list. What's your favorite area to explore in Texas?