For those going today: Capital Weather Gang's NatCast has 'Hot in the sun, pretty nice in the shade. Not a bad way to send the Nats into the all-star break, and near .500 to boot' with <10% chance of rain.
(It's days like this that make one grateful for those water vendors along Half street. My favourite is the one normally first along the row as one comes out of the Metro station, closest to 'Das Bullpen' - he's got $1 half-litre bottles as well as the $2 ones generally on offer.)
Still Metro trackwork going on on the Blue, Red and Yellow lines including Yellow line trains running at 24min intervals - budget time accordingly.