August 2023 – Warm with Below Normal Precipitation Across Delaware

August Temperatures

Preliminary data indicates that the statewide average temperature in August was 75.9^o F, which is 0.4^o F above the 1991-2020 mean value of 75.5^o F (Figure 1).  August 2023 saw temperatures that were in the top one-third of values since observations began in 1895.

August Precipitation

Delaware’s statewide precipitation for August 2023 averaged only 2.63 inches, 2.06 inches below the 1991-2020 mean of 4.69 inches (Figure 2).  This month’s statewide precipitation total was the 27^th driest August since observations began in 1895.

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were mixed across the state, but generally small at most stations (Figure 3).  Precipitation was uniformly below normal across the entire state, with many locations seeing negative anomalies of greater than two inches (Figure 4).

National Anomalies

Temperatures were generally below normal across the southern tier and Pacific Coast of the United States, with positive anomalies of up to 7^o F in east Texas and Louisiana.  Much of the Great Lakes and New England experienced below normal temperatures (Figure 5).   Negative precipitation departures were found across the Gulf Coast states and the Mid-Atlantic region.  Positive precipitation anomalies were found scattered throughout the nation, mostly associated with convective precipitation events (Figure 6). The 500 hPa height pattern for August shows a weak jet stream trough covering the western United States  and a jet stream ridge covering eastern Canada and the eastern portion of the U.S. (Figure 7).

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