Autumn Temperatures
Preliminary data indicates that the statewide mean autumn temperature of 57.8°F was 0.2°F above the
1981-2010 normal of 57.6°F (Figure 1). The near normal autumn temperatures followed four consecutive seasons with below normal temperatures across Delaware. Temperatures
have been quite variable across the State during the year (Figure 2), with seven of the first eleven months being below normal.
Autumn Precipitation
Near normal autumn temperatures were accompanied by slightly dry conditions across the state during the autumn season. The statewide
mean precipitation of 9.52 inches was 1.31 inches below the 1981-2010 normal of 10.83 inches (Figure 3). Monthly precipitation anomalies have varied between positive and negative during the year, but
no month has seen large departures from normal (Figure 4).
Statewide Spatial Averages
Data from the Delaware Environmental Observing System (DEOS) show that temperatures varied considerably across the State during the autumn season (Figure 5), with generally small positive or negative departures at most stations. The largest departures were found along the coastal areas of Sussex County where cool conditions were dominant.
Precipitation varied from as low as 7.51 inches along the Atlantic Coast to a high of 14.52 inches in western Chester County, PA. Even with this large variation, most stations in the region experienced slightly dry conditions during the season, with the greatest negative anomalies found along the Atlantic Coast and in northern Chester County, PA (Figure 6).