It has been signaled for several days now. I think of it this way.... today is just past mid fall (met) so probably some warmer stretches still to come. Those highs on the GFS, extrapolated out from the 2PM temps, would be over 10 degrees AN in the low and mid 70's. I remember sweating in my plastic Halloween costumes.
Some lucky lottery winners in Lanco with rain showers moving through.