Spider-Man: Far From Home ended on a major cliffhanger, with the wall-crawler's secret identity outed to the world and Peter Parker framed for the murder of Quentin Beck/Mysterio. Originally, the plan was for the untitled sequel (Spider-Man 3 ) to be released in theaters next July, but COVID-19 changed everything, and it's now been pushed back to December 17th, 2021.
Had things remained on schedule, production would have kicked off back in the summer. Later, it was moved to the Fall, with some overlap with the Uncharted movie Tom Holland is filming.
Holland himself actually pointed to this being the plan, with word on the next Spider-Man movie wrapping up by February. Now, though, it seems something has changed based on a report from The Direct. They claim that production has been shifted to "Winter 2021," meaning that cameras should start rolling on the Sony Pictures/Marvel Studios movie in January or February.
It now seems likely that between this rumoured production start date and when Spider-Man 3 is set to be released, the web-slinger's next adventure will actually be set during the winter as well. However, you have to hope this delay isn't going to result in the movie slipping further down the release calendar (and into 2022).
Time will tell on that front, but this is at least a semi-positive update on plans for the threequel.