Humidity is a measure of the amount of water vapor in the air. It is influenced by a variety of factors, including temperature, precipitation, and potential evapotranspiration (PET).
Cities with less precipitation and less PET, such as Syracuse, may still experience high levels of humidity because the air in these areas may have a higher water vapor content relative to its temperature. This can occur because the air in these areas may be more stagnant, meaning that any moisture in the air may not be carried away by wind or other atmospheric processes. Additionally, cooler temperatures in these areas may lead to higher relative humidity, as cooler air is able to hold less moisture than warmer air.
In contrast, cities with greater amounts of both precipitation and PET, such as Miami, may have lower relative humidity because the air in these areas may be more efficiently moved or replaced by air with lower moisture content. Additionally, higher temperatures in these areas may allow the air to hold more moisture, which can help to prevent the relative humidity from becoming too high.
Therefore, while precipitation and PET can influence humidity levels in a given area, they are not the only factors that determine relative humidity. Factors such as temperature, wind patterns, and atmospheric stability can also play a role in determining the humidity of a particular area.