Aerial thermal images of a ground surface may be captured using a thermal image sensor. The images may be contrasted, georeferenced, orthorectified, and/or stitched together to form a complete thermal image. The complete thermal image may include a plurality of pixels with display values corresponding to temperatures of the ground. Local temperature sensors may measure the temperature at locations on the ground. Based on display values for pixels corresponding to the locations on the ground and the temperature measurements, a curve mapping display values to temperature measurements may be calculated. Temperatures may be calculated for pixels for which the temperature was not previously known. Users may select a temperature range of interest, and pixels with temperature values within the temperature range of interest may be distinctively marked. The pixels may be marked with different colors based on where their temperature value falls within the temperature range of interest.