Austin in July is a 6 AM city. The temperature at sunrise sits in the high seventies; by 10 it is in the nineties; by 2 it is whatever the radio says and the wind smells like asphalt. The locals adjust. The trails fill up before work. The South Congress shops post hours that lean late. The good walking is all in the first three hours of light.
The picks below are graded for that window. South Congress itself is fully exposed once the sun clears the buildings around 9, but before that the east-facing storefronts shade the west sidewalk almost the whole way from the bridge to Annie. The Lady Bird Lake trail under the cypresses on the south bank stays cool a little longer. The Stay Cool router will push these later in the spring; in July it pins them to 7.