Mean of the AirTemperatureData[ ]?

Questions
, ,
1

Why:

AirTemperatureData["LESA", DateObject[{2020, 1}], Mean]

and

AirTemperatureData["LESA", {DateObject[{2020, 1, 1}], 
DateObject[{2020, 1, 31}]}, Mean]

give different outputs?

Thank you

Guillermo

2

Try…

AirTemperatureData["LESA", {DateObject[{2020, 1, 1}], 
  DateObject[{2020, 2, 1}]}, Mean]