If you’re taking part in the Monument Avenue 10K tomorrow morning in Richmond, prepare to get wet—not rain wet, but humidity wet. The forecast calls for cloudy conditions between 8 and 10 a.m. with temperatures in the low 50s. The humidity levels, however, will be right around the 90-percent range for the start of the 8:30 a.m. event. That means runners should expect to perspire quite a bit, so they’ll need to hydrate accordingly before the race.