1996 Plymouth Voyager Cold weather Starting

I am having problems with my starter not consistanly engaging when the engin is cold and the outside temp is below freezing. I have a new battery and starter relay, and can hear the "click" of the solenoide when the ignition is turned. After several tries, the starter does roll and the car does start. When the temp is above freezing, there doesn't seem to be any problems. Any ideas as to what may be the cause?