MacBookPro temperature inconsistency
In OSX you can also try many applications, one might give you the GPU or Motherboard temp instead of the CPU temp.

OSX temperature apps:

atMonitor or
smcFanControl

OSX might also take more resources than Windows. To minimize running apps, clear your startup items under Users in System Preferences, or check your Activity Monitor which shows your CPU% and Threads for each application, this way you can close apps that are using too much resources.