Well-designed LEDs perform well under typical ambient temperatures.  All Sunlite products are rated to operate well between -30°C and 40°C (-22°F and 104°F).  LEDs are very sensitive to heat, and although the LEDs will still perform well under their rated operating conditions, each 20°C increase in temperature will typically drop the life span by 10,000 hours.  The AC to DC driver for the LED is also heat sensitive, and each 10°C increase in temperature will typically cut the lifetime of the driver in half.  Unlike fluorescent lights, LEDs are generally not affected by cold temperatures and actually work more efficiently in a cold environment because the cold helps with removal of heat.