Your heating system will have the largest impact on your energy bill this winter.
The greater the difference between the outdoor and indoor temperature, the harder your heating system must work to keep your apartment at a comfortable temperature. For example, it costs more to keep your apartment temperature at 65°F on a day when the outdoor temperature is 20°F, compared to a day when the outdoor temperature is 35°F.
Below is a graph of average outdoor temperatures in Columbus, Ohio over the past three months. As you can see, the trend line shows that outdoor temperatures have been gradually decreasing since September. This means that your heating system is working harder to keep your apartment at a comfortable temperature. If you notice an increase in your energy bill during the winter months, it is most likely due to your heating system working harder to combat the colder outdoor temperatures.