9lb pork butt 30° to 175° in 5 1/2hrs in a MES @ 225°?

Is this possible: MES set at 225° (its on front porch and its 30° out), TWO 9 lb pork butts from frig to smoker, one with MB factory probe, one with Weber probe and after only 5 1/2 hrs MB prob says 194° and weber probe says 174°.  I was expecting a longer cooking time, say like 10 hrs., to get to around that temp.