Most repairs can be done in winter as long as there is no risk to the roofers from heavy rain or icy conditions. Roof installations can also be carried out in winter although the temperature can limit this on certain roof types. As an example, the best temperature to install an asphalt shingle roof is between 40 and 85 degrees. If a shingle roof is installed below these temperatures the shingles can become brittle and be more prone to breaking and cracking.