This could be
because of the urban heat island effect, which causes temperatures in the city to rise as much 10 °C compared with those in the surrounding areas.
The reality is that the social, environmental and economic costs
of urban heat islands add up to a bill that is too high for humanity to pay.
Scientists include older urban sites not because they are
ignorant of urban heat island effects, but because continuing to include them improves the accuracy of our identification of temperature trends.
In addition to reducing city temperatures more during a heat wave, the researchers also found that cool roofs can decrease the intensity
of the urban heat island effect more during extreme conditions.
Indeed, they found the
magnitude of the urban heat island effect decreased toward the start of the fall harvest season, when vegetation is removed from farm fields, leaves fall from trees, and plants become less active.
New York City Nights 15 Degrees Warmer Than Surrounding Areas Illustrating the amplifying effect
of the urban heat island on recent heatwaves, according to data collected by CCNY's New York City Meteorological Network, during the first July heatwave overnight temperatures were 10 - 15 °F higher in Manhattan than on Long Island or in western New Jersey, just a few miles away.
Urban morphology — the patterns of a city's physical configuration and the process of its development — has long been associated with the
formation of urban heat islands.
The more detailed
understanding of urban heat islands provided by the study can help health professionals and others target efforts to protect people and infrastructure from heat - related problems, according to project co-leads Tracy Twine and Peter Snyder, associate professors in the College of Food, Agricultural and Natural Resource Sciences.
However, temperature is officially measured at just a few locations in most cities, so awareness of the extent and
variability of urban heat island effects was limited,» said lead author Brian Smoliak.
The other effect that may exist here (but I am less certain of the science, commenters can help me out) is that by saying «your hometown» we put the bet into the
domain of urban heat islands and temperature station siting issues.
There are also extensive green roof systems — offering a mix of benefits including boosting biodiversity, reducing the
risk of the urban heat island effect causing an overheating risk, and assisting with stormwater attenuation, and each house is fitted with rainwater harvesters, significantly reducing any exposure to water charges.
I never challenged the
reality of urban heat islands, and merely assert that the station selection has largely succeeded in avoiding locations with increasing urban effects.
I like the way that temperatures need to be adjusted upwards to counter-act the
loss of the Urban Heat Islands since towns have shrunk so much recently.
The City's Department of Environment also commissioned a City Hall Rooftop Garden pilot project as
part of the Urban Heat Island Initiative with the US Environmental Protection Agency.