Wrong region for weather after ITV News on Saturday evening?

[Fluffy Bunny Feet]

Does anyone happen to know why some regions seem to treat the weather differently - e.g. Anglia and I think Tyne Tees tend to have the weather as an entirely separate thing, very specifically after the news has ended, whereas most other regions seem to incorporate the weather as part of the news, before the final sign-off?

It's simply an historic thing.
For example, Yorkshire's Calendar weather was combined then seperate for a number of years until the new MD (pre Granada merger/takeover) wanted the weather team to be part of the 'family'. It fell into local programming anyway so made sense I guess plus sponsorship added to the budget.