Methodology and Additional Source Info: This data was measured by the National Aeronautics and Space Administration (NASA)'s Landsat 8 satellite's earth observations, measured from 2013-2020 during the summer months (June, July, and August). The data was compiled and mapped for Fairfax County through a partnership between the Fairfax County Office of Environmental and Energy Coordination (OEEC) and the NASA DEVELOP program as part of the "Resilient Fairfax" Climate Adaptation and Resilience Plan process.Description: This map layer shows the areas within Fairfax County that were recorded as hotter than 100 degrees Fahrenheit on average during the summer months (June, July, August) for the years 2013- 2020. The areas with temperatures recorded as above 100F are shown in red, with darker reds indicating higher temperatures. This layer differs from the "Daytime Average Summer Temperature" layer because this layer includes only those areas that were hotter than 100 degrees F. These areas are known as "urban heat islands." The "urban heat island effect" happens because surfaces like parking lots, roads, dense buildings, and other infrastructure absorb and retain heat. Because of the "urban heat island effect," real temperatures within these hot spots on any given day are often much hotter than other areas within the county.

Methodology and Additional Source Info: This data was measured by the National Aeronautics and Space Administration (NASA)'s Landsat 8 satellite's earth observations, measured from 2013-2020 during the summer months (June, July, and August). The data was compiled and mapped for Fairfax County through a partnership between the Fairfax County Office of Environmental and Energy Coordination (OEEC) and the NASA DEVELOP program as part of the "Resilient Fairfax" Climate Adaptation and Resilience Plan process.Description: This map layer shows the areas within Fairfax County that were recorded as hotter than 100 degrees Fahrenheit on average during the summer months (June, July, August) for the years 2013- 2020. The areas with temperatures recorded as above 100F are shown in red, with darker reds indicating higher temperatures. This layer differs from the "Daytime Average Summer Temperature" layer because this layer includes only those areas that were hotter than 100 degrees F. These areas are known as "urban heat islands." The "urban heat island effect" happens because surfaces like parking lots, roads, dense buildings, and other infrastructure absorb and retain heat. Because of the "urban heat island effect," real temperatures within these hot spots on any given day are often much hotter than other areas within the county.