The only snowlike substance you'll find at Walt Disney World this winter is pixie dust. Make your kids' year and head to Orlando, Florida, where seven of the world's top theme parks—Magic Kingdom, Epcot, Disney's Hollywood Studios and Animal Kingdom, along with a number of water parks—vie for the family's glee. With average winter temperatures in the 70s, who knows, a balloon ride might even be in order (800/972-3304; visitorlando.com).
Visit Orlando 
As the nation's fourth-largest city, Houston is a family-friendly winter-vacation hot spot. With daytime temps in the 60s, Houstonians have to work at cooling off, which they do at an indoor ice rink at the Houston Galleria. For an out-of-this-world experience, rocket through Space Center Houston's flight simulators and moon rock display. Of course, for Midwesterners, a daytrip to the beaches of Galveston may be the only otherworldly trip you crave (800/4-HOUSTON or 713/437-5200 visithoustontexas.com).
Time stands still in Natchez, Mississippi a charming town on the Mississippi River. Here, visitors ride in horse-drawn carriages, tour homes straight out of Gone with the Wind and visit the reconstructed Grand Village of the Natchez Indians. If you and your kids have a taste for the history and flavors of the Deep South, Natchez will sate the whole family (800/647-6724; visitnatchez.org).
Winter is whale-watching season in Maui, Hawaii, and Lahaina Harbor—once the center of whaling in the Aloha State—is home to a variety of tours and even a whaling museum. When you've had your fill of humpbacks, "lei" back and relax at the Old Lahaina Luau, considered one of the most authentic around. With daytime temps in the 80s and nights in the mid-60s, winter doesn't get much better than this (800/525-6284; gohawaii.com/maui).
While the tourists are busy talking about the Alamo and navigating the River Walk, the locals and visitors-in-the-know are taking advantage of the countless family activities San Antonio has to offer. Check out the San Antonio Children's Museum, San Antonio Zoo, the Plaza Wax Museum, Dinosaur-Quest, miniature golf and parks galore. As a complement to its rich history, San Antonio is a magical playground for kids of today (800/447-3372; visitsanantonio.com).
As you land at Phoenix Sky Harbor International Airport, prepare to see something we Midwesterners often forget exists in the winter: The sun, which shines here more than 300 days a year. With high temperatures in the mid-60s and even 70s, your only stress in Phoenix will be narrowing the activities. Zoo or the Desert Botanical Garden? Hike or hot-air balloon ride? Steak or tacos? Oh, decisions, decisions (877/CALL-PHX or 877/225-5749; visitphoenix.com).