Do your windows get frost on the insides? If so it's probably the cheap windows. Single pane windows have terrible insulation and let out a lot of heat. Your landlord will never pay to replace them though because nice windows are expensive.

On the other hand, if your windows aren't doing that, it could be that the seal around the window is bad. Use weatherproof tape on the seams.

Coincidentally, I was watching an episode of Andor, the star wars TV show, so I ran to my window hoping that some cool star wars ships had actually appeared over my place. Sadly it was not to be.