Preliminary data indicates that the statewide average temperature in July was 81.0o F, which is 4.4o F above the 1981-2010 mean value of 76.6o F (Figure 1). July 2020 was the warmest July since observations began in 1895, and it is the warmest of any month on record since 1895 for Delaware.
Delaware’s statewide precipitation for July 2020 averaged 6.42 inches, 2.28 inches above the 1981-2010 mean (Figure 2). The July 2020 precipitation amount was the 17th wettest since 1895, placing this month in the wettest one-third of all Julys since the start of observations.
Statewide Spatial Anomalies
Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were above normal throughout the State (Figure 3). Precipitation was likewise above normal at nearly all locations (Figure 4).
Temperatures were above normal across most of the eastern one-third of the country, while below normal temperatures were found in both the northwest United States and along the Pacific coast (Figure 5). Precipitation varied greatly across the country as is common when convective rainfall dominates during the summer months (Figure 6). The 500 hPa height pattern for July showed a ridge dominating the eastern portion of North America leading to generally warm weather across that region (Figure 7).