If we can believe the weatherperson it appears we will leave the rain behind and move into some sun with temperatures in the mid 70's. In Seattle, the mid 70's will be comfortable and tolerable. If the needle inches over the 80 degree mark things start to get very uncomfortable for some folks. Many have issues with heat at that point. It has to be in the 90's before I become effected by the heat. If it is damp heat like here in Seattle I can tolerate mid 90's but I can go higher if in a dryer climate.
I have been investigating the weather history for many of the places we want to travel over the coming years. NOAA is a great source of information and data that indicates that the temperatures at the surface have risen significantly over the past few years. Snow now melts faster in the North Hemisphere and we have higher Carbon Dioxide ppm than any time in our history. Tapping the local weather prognosticators from around the country and you can pretty much put together a plan that will keep you out of bad weather.....well almost. Mother Nature doesn't like to be fooled.
My prayers are with those suffering in Oklahoma.