Pavement Temperatures and Effects: Introduction
When it comes to snow and ice control, pavement temperature matters more than air temperature. It tells us whether snow will melt on its own or if a deicer is needed — and which products will actually work. By paying attention to pavement temperatures, we can avoid using salt when it isn’t necessary or useful and use the correct deicer when needed. As a property manager or owner, you can provide your staff with a way to measure and use pavement temperature and make sure your contractors are using pavement temperature in their snow and ice operations decisions.
Air Temperature
When you think about winter temperature, you probably think about air temperature. Air temperature, as reported professionally, is typically measured five to six feet off the ground. Air temperature is primarily controlled by the sun, or solar radiation, with warmer air rising and cool air sinking. Air and pavement temperatures can differ by as much as 20 degrees Fahrenheit (°F) either higher or lower.
Pavement Temperature
Pavement temperature can be measured either within the pavement itself or at the surface. The pavement temperature can vary from the air temperature due to a variety of factors including weather, freeze and thaw cycles, shade, and pavement material. Because we remove snow on pavements and apply deicers to surfaces, it is important to understand that the pavement temperature of parking lots and sidewalks may be quite different than the air temperature at any given time.
The photo to the left shows a higher surface/pavement temperature than air temperature on a roadway. The photo to the left was taken at about 8 a.m. on a partially ice-covered asphalt driveway after an overnight snowfall and shows a lower pavement temperature than air temperature. The air temperature was 40°F and pavement temperature was 24.9°F.