One (not so) fine day 65 million years ago...

The day when the asteroid hit!
Late Cretaceous climate, showing cold at only one pole. Ocean circulation and weather patterns would have been substantially different from those of today.

Land temperatures near the Equator are warmer than corresponding sea temperatures.

The asteroid hit is shown consistent with the angled trench in the Chicxulub crater.
LEFT A little movie I cooked up in RayDream Studio 5. It is the climate map above placed on a sphere with appropriate axial tilt and a touch of 3D for character.

Mapping a Mercator projection back onto a sphere restores distorted relations such as the one cold pole. Mars has one pole much colder than the other (and is minus oceans), and has oscillating weather patterns different from Earth (although it has seasons).

Mars data and models coming soon!