Preliminary data indicates that the statewide average temperature in October was 56.1° F, which is 1.9° F below the 1991-2020 mean value of 58.0° F (Figure 1). October 2022 was the coolest we have experienced since October 2003 and was 7.0° F cooler than last October.
Delaware’s statewide precipitation for October 2022 averaged 4.16 inches, 0.22 inches above the 1991-2020 mean (Figure 2). This month’s precipitation value placed it the top one-third compared to October values since 1895.
Statewide Spatial Anomalies
Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were uniformly negative across the state (Figure 3) with some stations seeing negative anomalies topping 3.0° F. Precipitation observations were above normal in all areas except southwestern Sussex County. Slaughter Beach, DE recorded precipitation 6.6 inches above normal for the month (Figure 4).
Temperatures were above normal across most of the northwestern United States, with the largest positive anomalies found in Washington and Oregon. Only the Appalachians and parts of the southeast U.S. saw temperatures below normal. In general, dry conditions prevailed across much of the eastern half of the United States, except for the coastal Mid-Atlantic, and parts of New England. The Pacific Coast of the country also saw below normal precipitation values. The 500 hPa height pattern for October shows a jet stream trough over the eastern United States and a ridge over the northwest portion of the country contributing to the temperature anomalies across those regions (Figure 7).