The power of hourly weather data: Observed air temperature climate trends for pragmatic decision-making
Fig 6
Changes in (top) the number of heating degree hours and (bottom) cooling degree hours from 1978 to 2023 for 340 airports across the CONUS and southern Canada.
Statistically significant regression trends are colored by magnitude in terms of degree hours per decade. Dashed gray lines at 37 °N and 98 °W separate geographic quadrants representing the northeast, northwest, southeast, and southwest regions of the CONUS and southern Canada study area. Stations without significant trends are divided into categories of high variability (residual standard deviation ≥ median residual standard deviation) or low variability (residual standard deviation < median residual standard deviation). Basemap and country boundaries as in Fig 5.