I’ve been using the default Apple Weather app since getting my iPhone earlier this year. It’s been fine but over the last few days it seems to be less accurate in general.
I’m in Ireland if that matters.
Edit: Updated the title to include iOS specifically
OP I noticed and sent a message to a friend about this the other day. Weather on the iOS Weather app said it would be sunny but it was 100% overcast all day. I thought something is or was off with the app too.