What is the range of temperature for the royal palm tree?

The Royal palm is native to the Everglades of south Florida. Royal Palms are found planted through out the Middle East, where summer temperatures can reach 55 degree C and humidity levels up to 95% - although many of them suffer from fungal infections in these circumstances if the stem is damaged in any way. Lower temperature range I can't help with, except to say that they are able to tolerate temperatures down to about 13 or 14 degrees C