Chuck Jensen wrote:

>>"A venture (sic) would affect it the same but in the opposite direction.
A low
  pressure area will have a lower temp than ambient (which is why
  carburetors ice up at 50F.">>

Not really. The temperature drop in a carb venturi is primarily due to the
vaporization (atomization?) of the fuel - generally in the range of around
60 dF. While there may be some small second order effects from the pressure
drop of the air but it would be overwhelmed by the effects from the fuel.

Dan Schaefer