Question about PTP820 radio outdoor temperature spec

Following is what defined in PTP820C, PTP820S and RFU-C specification:

Environmental Specifications: ‐33°C to +55°C (‐45°C to +60°C extended)

it is refers to the ambient temperature, basically it means the  air temperature around the radio. It is not the "feel like" temperature, it has nothing to do with humidity or wind. 

Here is the right way to measure the ambient temperature:

Keep the thermometer out of direct sunlight

- Don't place your thermometer too low near the ground or too high above it

- Place the thermometer in an open, well ventilated area

- Keep the thermometer covered

- Place it over a natural (grassy or dirt) surface

Following link provide a detailed explaination