DC's early November warmth

An early November day in suburban Washington, D.C.

The nation’s capital has averaged one 80-degree November day roughly every five years dating back to the mid-1990s. Washingtonians already had one 80-degree day on November 1, when the high was 83°. That’s what makes today’s highs near 80° and tomorrow’s highs in the low 80s all the more unusual for the nation’s capital.

Although the nation’s capital had an 80-degree November temperature as recently as 2022 prior to last Friday, there haven’t been two 80-degree November days since 2003. Five of the last seven November’s have also been cooler than average in the nation’s capital so any 80-degree warmth this late in the season has felt especially warm.

While the recent trend has been for November to be a cooler than average month in the nation’s capital, eight of DC’s 15 warmest November’s have occurred just since 2000. NOAA’s current weather averages (for temperatures and precipitation) are updated every decade and the current averages reflect the 30-year period of 1991-2020.

That means with the exception of 2022, all eight of DC’s very warm November’s since 2000 were taken into account in NOAA’s updated statistics. Some of that can be attributed to the urban heat island effect, but the overall trend has been for warmer than average temperatures compared to NOAA’s previous 30-year period of 1981-2010.

A warmer and drier than average November doesn’t correlate to a warmer and drier than average winter the same way a colder and wetter than average November doesn’t foreshadow a snowier than average winter. This fall has been warmer and drier than average in the nation’s capital and NOAA’s November outlook is for more of the same.

Not only are more above average temperatures in store for the nation’s capital this week, but drier than average conditions will also continue as my colleagues and I on the WUSA9 Weather Team aren’t expecting any beneficial rainfall over the next 7 – 10 days. 

DC’s Warmest Novembers (Source: National Weather Service)

1. 54.8° (2001)
2. 54.4° (1979, 1975)
3. 54.3° (2020, 1985)
4. 54.0° (1931)
5. 53.7° (2015)
6. 53.3° (1994)
7. 53.1° (2003, 1999)
8. 52.6° (2022, 2016)
9. 52.4° (2011)
10. 52.2° (2009, 1978)
11. 52.0° (1990)
12. 51.8° (1982, 1977, 1946)

DC’s dry start to November

 

October 2024 finished as a warmer and drier than average month in the nation’s capital for a second consecutive year. The nation’s capital experienced its warmest Halloween since 1950 with a high temperature of 83°. Last month’s 1.48” of rain at National Airport is notable for occurring entirely on the first two days of the month.

October’s warm conclusion continued on November 1 with a high of 83° in the nation’s capital.  However, cooler, more seasonal weather has arrived this weekend with highs closer to average in the 60s. Normally, D.C. residents see falling temperatures throughout the month with average daily/high low temperatures ranging from 64°/46° on November 1 to 53°/38° on November 30, according to NOAA. 

D.C.’s warmest November temperature on record of 86° occurred on November 1, 1974. Meanwhile, D.C.’s coldest November temperature of 11° was on November 30, 1929. Five of the last seven November’s have been cooler than average in the nation’s capital. However, November’s outlook from NOAA’s Climate Prediction Center is for above average temperatures and near to below average rainfall in the D.C. Metro Area.

D.C. residents have seen a fair amount of dry November weather over the last 20 years. There were two notable exceptions with November 2018 that finished as D.C.’s wettest on record with 7.57”. November 2020 also finished as D.C.’s sixth wettest (6.14”). November rainfall average in Washington, D.C. is 2.91”, according to NOAA.

Longtime Washingtonians may recall the record-setting Veteran’s Day 1987 snowfall when 11.5” accumulated. That remains D.C.’s largest November snowfall on record. There has only been one instance of accumulating November snowfall in the nation’s capital over the last two decades. A daily snowfall record of 1.4” occurred at National Airport on November 15, 2018. Although the 2018-2019 winter season was the last to be snowier than average in the nation’s capital, November snowfall isn’t a reliable predictor of what the upcoming winter season will be like.

Since there’s been so little November snowfall in recent years, NOAA’s average November snowfall total for Washington, D.C. decreased from 0.5” to 0.1” in 2021 when the climate averages were updated.

Weather Quiz

 

Near record-warmth for Halloween 2024!

True or False.

Despite today’s September-like warmth in the low 80s, six of the last 10 Halloween’s have been cooler than average in the nation’s capital. 

A frightful or delightful Halloween?

 

October 2024 will finish as a warmer and drier than average month in the nation’s capital for a second consecutive year. DC residents will also experience one of the warmest Halloweens in recent memory, if not all-time, with highs around 80°.

The nation’s capital will see at least five days of 80-degree warmth this month, thanks to highs near 80° both today and tomorrow. That’s above the average of between three and four such days (for the 30-year period of 1994 – 2023). But, it’s less than the eight such days that occurred in both 2021 and 2023.

Despite the warm days, this month has also featured some cooler than average weather. Although lows downtown fell to 44° on the coolest mornings of October 17 and October 28, Dulles Airport had a low of 31° on October 28 giving it its first October temperature at or below freezing since October 30, 2022 (31°). Meanwhile, BWI Airport had a low of 32° on October 17 and 31° on October 28. Prior to this month, BWI had not seen October temperatures at or below freezing since 2018. Meanwhile, it has not been at or below freezing at National Airport during the month of October since 1992.

Measurable rainfall hasn’t occurred in the nation’s capital since October 2. Consequently, this month will finish with only 1.48” of rain. That’s well below DC’s monthly average of 3.66”, making this the fourth consecutive drier than average October. The warm and dry weather on Halloween should please trick-or-treaters.

Whether or not DC’s October 31 record high of 85° is approached (1950), this will be one of DC’s warmest Halloween’s on record. DC’s warmest Halloween over the last 30 years occurred in 2019 with a high of 77°. By comparison, last Halloween was chilly with a high/low of only 55°/41°. DC’s average high/low in the nation’s capital on October 31 is 64°/46°.