No weather information in Yosemite Notification Center

Solution 1:

I had the same problem and this fixed it:

1. Open Notification Center
2. Click the grey Edit button at the very bottom
3. Click the red minus icon (-) next to Today to remove it
4. Click the green plus icon (+) next to Today Summary to add it back

Once I added it back, the weather summary popped up.

Solution 2:

1. Try to switch off and on again the weather-location mode.
2. Disable and enable again "Today" item in your notifications.
3. Restart your system.

It helps to me.

Solution 3:

Check that you have allowed weather to access your current location.

In System Preference -> Security & Privacy -> Privacy tab -> Location Services