This old garden favorite was grown at the childhood home of Thomas Jefferson, who also grew it at Monticello
'Snaps' actually prefer cooler temperatures to thrive, and their 'high' seasons are typically Spring, early June cooler days, and Fall. Optimal temps for these beauties is between 70 - 80 degrees F. They can withstand light frosts.
Once it starts to get hotter, snapdragons slow down their flowering unless moved to a cooler, more shady spot away from direct sunlight.
Snaps come in hundreds of varieties in almost every color and size, and can easily be grown from seed (but nursery grown packs are a good way to go so that you get the most out of their flowering while it's still relatively cool).
Here's an excellent article detailing everything you need to know about growing these wonderful flowers.
Snapdragons make showy 'thrillers' (tall plants) in container gardens.