It should show up as long as location is on for weather.
I have both background app refresh and location services turned on for weather. Any other ideas/fixes?
Weather is not showing up for me either in GM. Granted, the "Weather by TWC" is there... weird.
It's definitely an option in Yosemite's Notification Center - I wonder if it was just a huge oversight on their part.
Try opening the weather app. Sometimes it takes a while, but if location for weather is turned on and today view is in NC, it should show up.
On a side note, they FINALLY fixed the bug I was having with "conditions with low visibility" being added to every weather forecast.