Residential electric bills follow uniform patterns from year to year. When a bill is higher than usual, naturally it arouses your curiosity. The cost of electricity in the home varies with seasonal use. In most homes, more electricity is used during summer and winter than in fall and spring. Summer means increased use of electricity for air conditioners, fans, refrigerators, freezers, dehumidifiers and washers and dryers. In the winter, higher bills are commonly a result of hot water heating, home heating, additional cooking, lighting and home entertainment. The water coming into the water heater in the winter is colder so requires more electricity to bring it up to the desired temperature. And even where oil or gas is used to heat the home, electricity is needed to operate the pump and fan motors on the furnace. Nights are longer in the winter, requiring use of lights about twice as long as in the summer. Also, most families spend longer hours watching television. Any one of these reasons isn't too important by itself, but together they help explain why so many people find their electric bills higher in summer and winter than in spring and fall.