Cities across the Northern Hemisphere are preparing for the upcoming summer months, which are expected to be warmer and drier than average. The European Center for Medium-Range Weather Forecasts warns about temperatures rising above the norm in central and southern Europe this summer. Similarly, the forecast for the Unites States predicts hotter weather and below-average rainfall likely to fuel a megadrought. This poses threats for citizens, especially in larger cities, where heat-absorbing asphalt and waste heat generated by energy use create a “heat-island” effect. It translates to temperatures being up to 10°F (5.6°C) warmer in cities compared to the surrounding natural areas.