Julison - There is a good "brainiac" but quick and dirty explanation about the effects of temperature on chemical and other physical reactions.
The basic rule is that there is a dynamic increase in effectiveness when temperature increases. The bottom line is that depending on the composition of the compound warmer is better because the compound is reacting with the metal.
Also, the metal will be much colder than the outside air or hotter than the outside air depending on conditions and that is a consideration. In cold weather your AS will be even colder on the surface than the air temperature.
If you do it in the winter is sounds like you might work harder or not get optimum results, but anything is possible.
Look at the site. Its interesting.