Preliminary data indicates that the statewide average temperature in October was 62.6°F, which was 5.5°F above the 1981-2010 normal of 57.1°F (Figure 1). October 2017 was the 2nd warmest October since 1895. Only October 2007 has been warmer.
Delaware’s statewide precipitation for October 2017 averaged 3.69 inches, 0.23 inches above the 1981-2010 mean (Figure 2), placing it just above normal for the month.
Statewide Spatial Averages
Data from the Delaware Environmental Observing System (DEOS) show that temperatures were above normal across the entire State with the largest positive temperature departures found across Chester County, PA and northern New Castle County, DE. (Figure 3). Precipitation departures varied according to location across the region (Figure 4), with no departures greater than two inches.