If you're waiting for rain think again. You're going to have to water the petunias without mother nature's help.  My hubby's been watering our flowers and tomatoes early every morning to insure everything doesn't dry up.   I spent the last few months buying lavender plants basically i know they can stand the heat and don''t need much tender loving care but the rest of my  garden is another story so a little water has to be distributed to those poor little plants that are sitting in the heat all day.  The same with you and your kids .  Bring plenty of water to hydrate the kids if you're planning another day trip or sending the kids to day camp.   These are the lazy hazy crazy hot days of July!!!!!!!!!