DC’s volatile October weather

 

An October day at the farm

October is a transitional weather month as average daily temperatures and the amount of daylight each decrease throughout the month. That’s not to say there aren’t very warm October days in the nation’s capital, much like early winter’s chill can also occur.

Given the decreasing daily amount of sunlight and lowering sun angle as October wears on, it gets harder for very warm weather to occur. That said, there’s been no shortage of unusually warm October weather in recent years. For example, DC’s hottest October temperature on record of 98° occurred on October 2, 2019. To add to that, Halloween’s high temperature of 83° in 2024 was the warmest October 31 in the nation’s capital since 1950.

DC has averaged between three and four October days with highs in the 80s over the last 30 years. This month has already featured five days with highs in the 80s. Although 90-degree October heat is less common with only one such occurrence roughly once every four years, DC residents experienced 90-degree heat on October 14 (90°). That also set a new record for latest in the calendar year that 90-degree heat has occurred.

October lows in the 30s also occur on occasion in the nation’s capital. Such chilly temperatures, however, have been less common in recent decades. Washington, D.C. has averaged only between one and two October days with lows in the 30s over the last 30 years, with the most recent on October 19, 2022 (38°), according to NOAA data. 

There hasn’t been an October temperature at or below freezing in the nation’s capital since 1992. That can be attributed in part to a warming climate, as revealed in NOAA’s updated climate averages for the period of 1991-2020. The relatively warm decade of the 2010s replaced the cooler 1980s for this update. Also, there’s a more pronounced urban heat island effect now than in past decades due to increased urbanization and automobile traffic. Six of DC’s 15 warmest October’s have occurred in just the last decade.

DC’s warmest October’s (Source: NOAA)

1. 67.1° - 2007
2. 66.3° - 2021
3. 65.2° - 1984
4. 64.9° - 2017
5. 64.7° - 1971
6. 64.5° - 1947
7. 64.4° - 1941
8. 64.1° - 2019
9. 63.4° - 1949
10. 63.3° - 1943
11. 63.2° - 1975, 1919
13. 63.1° - 2023, 2016
15. 63.0° - 2024, 1879

Destructive October hurricanes

 

Wilma makes landfall in Florida, October 2005 (Source: NOAA)

Although the tropics tend to get quieter as October wears on, it can still be an active month in parts of the tropical Atlantic. The last two October’s have produced devastating hurricanes, while Isaias also developed earlier this month.

Melissa: Last October saw the third Category 5 hurricane of the 2025 season. Melissa was the final named storm of the season and broke a slew of records. It ranks as one of the strongest hurricanes on record in the Atlantic Ocean Basin and was the most intense hurricane to ever make landfall in Jamaica. At peak intensity, Melissa had sustained winds of 190 mph and a minimum central air pressure of 892 millibars (mb). By comparison, standard sea level air pressure is approximately 1013 mb. The lower the air pressure, the stronger the storm is.

Milton: The second Category 5 hurricane of the 2024 season, Milton had peak winds of 180 mph and a minimum central air pressure of 895 mb. Fortunately, Milton weakened to a still powerful Category 3 storm when it made landfall on the west coast of Florida on October 9. It was an exceptionally destructive storm that caused $34.3 billion in damages (2024 dollars), according to NOAA, along with 32 fatalities. Milton’s lowest pressure of 895 mb tied it with 2005’s Hurricane Rita as the fourth strongest Atlantic hurricane on record.

Michael (2018): Hurricane Michael became only the fourth Category 5 hurricane to make landfall in the United States and first since 1992. It also remains one of the few hurricanes that intensified up until its landfall. Michael reached peak intensity as it made landfall along the Florida panhandle with sustained winds of 160 mph and a minimum central air pressure of 919 mb. That part of Florida had seen several Category 3 hurricanes, but never a Category 4 or 5 storm. Michael caused $31.2 billion in U.S. damages (2024 dollars) and claimed 16 lives during the storm, according to NOAA.

Wilma (2005):  Before impacting the United States, Wilma became the strongest Atlantic hurricane on record with a minimum central air pressure of 882 mb. Its sustained winds reached 185 mph, making it a Category 5 hurricane. Fortunately, Wilma weakened significantly before it reached southwest Florida where it made landfall on October 24 as a Category 3 storm. It caused $30 billion in damages (2024 dollars) and five fatalities.

Mitch (1998): Mitch was upgraded to hurricane status on October 24 in the western Caribbean Sea. Due to favorable environmental conditions, Mitch quickly intensified into a Category 5 storm. At peak intensity, Hurricane Mitch had sustained winds of 180 mph and a minimum air pressure of 905 mb. Although Mitch weakened before impacting Central America, it caused devastating flooding in Nicaragua and Honduras. NOAA’s estimated death toll for Hurricane Mitch was approximately 11,000. 

Weather Quiz

 

Hurricane Milton, October 2024 (Source: NOAA)

What October hurricane gave Washington, D.C. its highest wind gust on record ?

A.  Milton


B.  Sandy


C.  Hazel


D.  Isaias