" I will need something logical, as my child is very smart, it cannot be, "well, certain areas are cold and certain areas are hot""
How is that not logical? Weather is what happens day-to-day, while Climate is on the spans of decades or centuries. Also, it s Global Warming , not United States Warming .
And if you look at the recent temperature data for the last week compared to averages for those dates, you ll see that what is happening is that North America is colder than average, but *the entire rest of the world* is warmer. We currently are experiencing a temporary shift in the jet stream that is blasting pretty much all of that cold Arctic air at North America. Which would be like having a house where you had one room with a window into the rest of the house and put a room AC unit in it. It will cool off that one room, but heat up the rest of the house.