How can I weather proof my windows

May sound insane but moistened bubble wrap. Through the season it may turn loose but just a spritz if water and you're back in business. a few years back we had a brutal winter. My double panes weren't doing a good enough job so I saw where bubble wrap will put that necessary dead air space and it worked.

They sell weather striping and window kits you use use with a blow dryer and these are very ez to put up. Comes with two side tape you put around the frame, then you pull the tape strip off each section as you place the clear film on, once all section are on that when you usebthe hair dryer.

I found a very reasonably priced large quantity (bag of 20 for $16.00 earlier this year)of folded Mylar in 54" X 84" pieces. I double taped 2 pieces for my sliding glass door, and glued one end of the Mylar over a light weight curtain rod to create a Mylar hem to hang the Mylar over regular windows. It reflects the sun away during the summer, and adds some insulation during the winter. Only drawback for me was that it does darken the rooms. You can see out during the day, but others can see in during the night if the windows are not also covered with privacy curtains. Be careful unfolding and cutting the Mylar because it is pretty delicate to use.