The Weather Effect

When the temperature is hot, you’re also hot. But a dry heat feels completely different than a damp heat. Humidity has a huge impact on our utility bills, because when we feel hotter, we feel more uncomfortable. So what do we do? We turn the thermostat to a colder setting. While rainfall can cool things off, it adds humidity. How long the rain lasts and what time of day it comes will also impact how long your air conditioner runs to meet the thermostat settings.

The most common weather indicators are temperature, degree-days and rainfall:

  • Temperature: An easy way to describe the impact of temperature is using the number of days over 90°F in the summer or under 40°F in the winter. The more days we experience these extreme temperatures, the more it will cost to run heating or cooling equipment.
  • Degree-days: A degree-day is the difference between the average daily temperature and 65°F (that nice temperature when no heating or cooling is necessary). The resulting number is called a degree-day. The greater the difference, either above or below 65°F, the greater the heating or cooling requirements and the longer it will take to bring temperatures to our thermostat settings.
  • Rainfall: In Northeast Florida, we receive about 55 inches of rainfall in an average year. This chart shows how humidity affects our comfort when heat and humidity both rise. 
How Temperature and Humidity Combine To Make It Feel Hotter

As you can see on the chart above, as humidity goes up, our perception of how hot it is outside goes up. Check it out: On the left, find the 95°F air temperature, as you move right across the chart (indicating a rise in the humidity) the temperature you feel or "apparent temperature" rises. For example, when air temperature is 95°F and relative humidity is 40 percent, the outside temperature feels like it is 101°F. That’s hot!