Diurnal Variation of Relative Humidity

  • Q: Given that the amount of moisture at a particular location is contant during a 24 hour day, (i.e., the mixing ratio is constant) then what will the diurnal variation of RH look like?

  • Q: Why does this happen??

  • Q: When is the best time to water your lawn to minimize evaporation?  


  • Q: Why do your lips seem so dry in winter?  


  • Q: On a given day in winter, is the RH larger in a house or outside?  


  • Q: Is the evaporation rate greater inside the house or outside? 



1.  Suppose the dew point of cold outside air is the same as the dew point of warm air indoors. If the door is opened, and cold air replaces some of the warm inside air, would the new relative humidity indoors be (a) lower than before, (b) higher than before, or (c) the same as before? Explain your answer with the aid of a diagram