Can you tell me how the average relative humidity in the summer months in Raleigh North Carolina, compares to the average relative humidity in the summer months on Long Island, New York?

MIKE MOSS SAYS:     Mike,     Using comparative climatology tables from the National Climatic Data Center for the two regions, here are the figures I came up with:

For Raleigh, average summertime Relative Humidity is 88% at 7 am, 57% at 1 pm

For Long Island (based on Islip observations), summer RH is 74% at 7 am, 55% at 1 pm

Note it is useful to include both morning and afternoon readings, since RH is dependent on both the temperature and the amount of water vapor in the air, and thus tends to maximize around sunrise and reach a minimum in the afternoon.