Spotted in D.C.: The year’s first premature flip-flop wearer. (Kohl's)

But there’s one indicator of spring that’s even more reliable than science: According to chatty journalists, the first premature flip-flop sighting of the season happened this morning. It’s as sure a sign as any that warmer temps are on the way.

On the off chance you need ideas for ways to spend this gorgeous day, we’ve compiled a list of activities and related news, starting with the secret life of food trucks:

View Photo Gallery: The District’s once-small food truck community is now a veritable fleet of mobile kitchens. Here’s a look at some of the freshest and flashiest of Washington’s four-wheeled lunch vendors, where you can often grab lunch for $10 or less.

(Obligatory cherry blossom photo) (Astrid Riecken for The Washington Post)

• Washington is only a few days away from the earliest-ever peak bloom time for its famed cherry blossoms. If you haven’t heard, the Capital Weather Gang made its predictions for the year’s bloom dates Monday. We could be seeing the pink flowers as early as Sunday.

• Are you sneezing more than usual this year? Yeah, us too. “The mild winter has resulted in very high pollen levels in February and early March, when they’re typically very low or negligible,” Derek Johnson, medical director of the Fairfax Allergy, Asthma and Sinus Clinic, told The Post’s Carolyn Butler.

Tell us: How will you spend it?