This is a very good site for seeing old weather forecasts
https://www.youtube.com/user/treffynnon19/videos
A lot of old national news reports have been uploaded along with forecasts at the end of the news.
Here's an example, New Year's Day 1985
https://www.youtube.com/watch?v=XE4K7ZBSg2g
MANCHESTER SUMMER INDEX for 2021: 238
Timelapses, old weather forecasts and natural phenomena videos can be seen on this site
http://www.youtube.com/channel/UCgrSD1BwFz2feWDTydhpEhQ/playlists