October 2024 – Record Dry Conditions with Near Normal Temperatures

October Temperatures
Preliminary data indicates that the statewide average temperature in October was 59.0°F, which is 1.0o F above the 1991-2020 mean value of 58.0°F (Figure 1). October’s temperature was the 28th warmest since records began in 1895.

October Precipitation
Delaware’s statewide precipitation for October 2024 averaged 0.03 inches, 3.91 inches below the 1991-2020 mean of 3.94 inches (Figure 2). October 2024 was not only the driest October since observations began in 1895, but the driest month ever observed across Delaware. In addition, the two-month period (September and October) was the driest two-month period ever observed across the state!

Statewide Spatial Anomalies
Data from the Delaware Environmental Observing System (DEOS) show that temperature departures varied between small positive and negative values depending upon the exact location across the State (Figure 3). Precipitation anomalies were uniformly negative across the entire state, with most departures ranging between 3 and 4 inches below normal for the month (Figure 4).

National Anomalies
Temperatures were near or above normal across the entire United States in October (Figure 5). Some locations in the southwest portion of the country saw anomalies of up to 9°F. Precipitation was below normal across most of the country (Figure 6). Much of the eastern one-half of the United States saw precipitation deficits of between 2 and 4 inches. The 500 hPa height pattern for October showed an anomalous jet stream ridge across the entire United States (Figure 7) contributing to the temperature anomalies across the country.

Global Anomalies
October 2024 ranked as the second warmest October on record for the globe since 1850. Global temperatures were 1.32°C (2.38°F) above the 1901-2000 mean. Particular warmth was found across the United States and the Arctic (Figure 8).

Images