Summer is over.
Snow fell over the weekend from Montana to Kansas, dropping about a half-foot in parts of Colorado and Nebraska, according to the National Weather Service. Upper Michigan also saw a little snow.
In Pennsylvania, temperatures hit the freezing mark this morning in the Pittsburgh area, and frost advisories were issued for many central counties for this morning and overnight Tuesday.
Sunday, Philadelphia had its coolest temperatures since April, with a low of 48 and a high of 54.
Tonight could be even chillier, dipping into the mid 40s, with highs in the upper 50s the next two days.