Is the urban heat island effect as evident in winter as in summer?
The urban heat island effect results when solar radiation heats up pavement and building surfaces in urban areas while this same energy is used for evaporation and transpiration in rural areas. At night, energy from Earth radiates more rapidly to space in rural locations, while building inhibits the same amount of heat loss in cities. Thus, the urban heat island tends to keep cities warmer, sometimes up to 10 to 15° F, both day and night than the surrounding countryside. We don’t think about life-threatening heat waves during the winter, but the urban heat island effect can still keep cities significantly warmer than surrounding areas. While the lower angle of the sun and shorter days reduce solar radiation everywhere in the winter, the concentration of heating sources in cities can still keep urban areas much warmer than rural locations. There’s plenty more about urban heat islands on this USA TODAY resource page.
