Want to reseed in the winter?
There are a handful of options, all affected by temperature and irrigation.
You can try dormant seeding, which occurs when the tempurature has cooled and the ground has endured some frost. The seeds wont germinate now but it will germinate in the spring time
You need to consider whether the tepmperature will rise again and allow the seed to partially germinate. If that happens, the seed will die once the temperaturre drops.
Replacing small patches of lawn with sod is also an option during the colder months. You can do sod in the winter if you can get it.