The underlying aeronautical Terminal Aerodrome Forecast (TAF) standard, which is what is used by our WeatherForecast function, unfortunately does not currently provide temperature and dewpoint information for any airports that I am aware of.
The National Weather Service explains: “The international TAF also contains forecast temperature, icing, and turbulence. These three elements are not included in National Weather Service (NWS) prepared TAFs. The U.S. has no requirement to forecast temperatures in an aerodrome forecast”
However, I’m not currently aware of any airports that actually include temperature/dewpoint in their TAF. The closest that I can find after a very cursory search through our data is some Australian airports seem to include some values that look like temperatures and barometric pressures in the “RMK” (remarks) section of their TAFs:
YKII 130049Z 1301/1314
28010KT 9999 -SHRA SCT015 BKN020
BECMG 1309/1311 01008KT 9999 NSW FEW015
T 14 15 14 13 Q 1021 1019 1019 1021
If the airports you are interested in provide that optional extended information, then you should be able to parse it out of the WeatherForecast function by looking at the “raw_forecast” element that we return.