Preliminary data indicates that the statewide average temperature in November was 52.1o F, which is 4.5o F above the 1981-2010 mean value of 47.6o F (Figure 1). November 2020 was the 2nd warmest November since observations began in 1895. Only November of 1985 has been warmer.
Delaware’s statewide precipitation for November 2020 averaged 5.77 inches, 2.37 inches above the 1981-2010 mean (Figure 2). This placed this month’s precipitation total as the 8th highest of all months since 1895.
Statewide Spatial Anomalies
Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were positive at all stations, with the largest anomalies found across Kent and New Castle Counties reaching to approximately 6o F at some stations (Figure 3). Precipitation was above normal throughout the State, with departures of greater than four inches common across many areas (Figure 4).
Temperatures were above normal across nearly the entire United States, with the largest temperature anomalies (5o F – 10o F) found across the north-central portion of the country (Figure 5). Precipitation anomalies varied greatly across the country with particularly heavy rainfall along the Atlantic coast from Florida to Delaware (Figure 6). The 500 hPa height pattern for November shows a jet stream ridge covering the eastern two-thirds of the United States (Figure 7). The placement of the jet stream north of its normal position is responsible for the warm temperatures seen across the country.
- November 2019 – Cold and Dry Across Delaware (2019)
- November 2018: Record Precipitation and Cold Conditions Across Delaware (2018)
- November Climate Conditions – Dry with Near Normal Temperatures Across Delaware (2017)
- Very Warm, and Moist Conditions Characterize the 2016 Autumn Season Across Delaware (2016)