The power of hourly weather data: Observed air temperature climate trends for pragmatic decision-making
Fig 5
Changes in (top) the number of hours below 0 °C (32 °F) and (bottom) number of hours above 30 °C (86 °F) from 1978 to 2023 for 340 airports across the CONUS and southern Canada.
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. Statistically significant trends in units of hours per decade are shown in colored circles. Warming trends are denoted in shades of red and orange for both maps. Insignificant 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). Stations with insufficient threshold hours passed all filtering procedures but have a median of < 10 threshold hours each year for the corresponding metric across the 46-year period. Basemap and country boundaries were plotted using the Mapping Toolbox for MATLAB [48]. The public domain base layer shapefiles are from Natural Earth.