It's finally spring: The snow is disappearing, the Charles is no longer frozen, and you can actually wear shorts outside without fear of frostbite. Celebrate the 50—and dare we say 60—degree weather with a jog outdoors, unencumbered by layers of cold gear and fleece. To get started, here are some running routes, all of which begin at the Curious George Store in Harvard Square:

Porter Square, 2 miles: Run up Mass. Ave. away from the river, make a stop at Shaw's, run back.

Eliot Bridge, 2.4 miles: Run down JFK St., turn right at the river, run along Memorial Drive, cross Eliot Bridge, run back and cross the JFK Bridge.

Inman Square loop, 3.4 miles: Jog to Annenberg, continue on Cambridge St., turn right on Webster Ave., turn right on Mass. Ave., run back to the Square. Resist the urge to stop at Toscanini's.

B.U. Bridge, 4.4 miles: Start down JFK St., cross the JFK Bridge, turn left and run along Memorial Drive, cross Storrow Dr., cross the B.U. Bridge, turn left and run back to the Square along Memorial Drive.

Fresh Pond, 5.6 miles: Run up Mass. Ave., turn left onto Garden St., continue onto Concord Ave., run a lap around Fresh Pond, run back.