Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
iOS 6 Evasi0n Jailbreak Disables Weather.app
Todays release of the untethered iOS 6.1 Jailbreak has went with out many problems considering it has already been download 270,000+ times with in only 4 hours of release.
It has been pointed out that once you Jailbreak your device with evasion your Weather.app will not open. You can still view the weather widget in notification centre but if you want an in depth forecast there is plenty of other free weather applications available for free in the App store until the bug is fixed in the coming days.
If you have any problems please be sure to let us know via the comments below or email us Tips@MacReviews.com
Pod2g has recently commented on the weather app bug and said:
We are currently investigating the weather app problem. A fix will popup on cydia when the problem is understood.