As a Ham Radio operator I see the same thing and have for years.. I also watch an internet show called 'Ham Nation' (you can google for it.
Skip to the part where Doctor T. Skove talks about space weather (Solar activity) and you will have your explanation.
SUN spots. Coronal holes and solar winds and Coronal Mass Ejections. We have had a very active summer.. Now Dr. T mostly talks about "Low bands" (1.5 to 30 MHZ) not TV bands (56 MHZ to microwave) but she also mentions GPS (microwave) and "Space Weather" (Oh her web page is spaceweatherwoman.com) affects all of this.
I see that all the time.. Lots of technical stuff (Which I am still learning) left out of this post.. Lots and lots of it.
