Latitude vs. Humidity

Though we might expect the planet to be equally humid on either side of the equator, this chart indicates the Northern Hemisphere tends to be more humid. The Northern Hemisphere has a greater distribution of Earth's land mass, while Earth's oceans are more widely distributed across the Southern Hemisphere. This paper concludes that this causes a higher rate of greenhouse trapping, resulting in warmer temperatures for both land and oceans. Because humidity is higher in areas close to warmer water (think of the U.S.'s east coast vs. west coast'), it is understandable that the Northern Hemisphere would experience an overall higher rate of humidity.