I took a train to DC on Monday. I hadn't visited the National Gallery of Art in a VERY, long time. We got there a bit early and so walked about the building looking mostly for shade. There was a cool oasis with a fountain on the southside of the building right next to the long staircase leading to what used to be a main entrance. We spent 10-15 minutes enjoying the relatively cool air in the shade with the mist from the fountain. We then walked to the north side of the building and across the street to the Mellon Fountain which is actually still a part of the National Gallery. The image below is from that fountain looking towards the gallery. The temperature was in the mid nineties with the humidity very close to that same number. Finally our ticket time arrived and we entered the cool, quiet building.
Mellon FountainNational Gallery of Art Mellon Fountain