Air Temperature
Temperature of the air measured approximately eight feet above the ground.

Dew Point
Temperature at which the air is fully saturated with moisture.

Relative Humidity
Measure of the amount of moisture present in the atmosphere, expressed as a percentage.

Average Wind Speed
Average wind speed within a one minute period, expressed in miles per hour.

Wind Gust
Maximum wind speed within a one minute period, expressed in miles per hour.

Average Wind Direction
Average wind direction within a one minute period, expressed as the direction the wind is blowing from.

Precipitation
Precipitation in the atmosphere (not the roadway surface). Expressed as "Yes" (presence of some type of precipitation), "None" (precipitation is not occurring), or an indication of the specific type of precipitation expressed in inches per hour.

Location
Physical location of the sensor.

Surface Temperature
Measurement of the temperature of the roadway or bridge surface.

Sub Surface Temperature
Temperature approximately 18" below the roadway surface.