How does DC’s September weather stand out?

 

A September day on the grounds of the National Cathedral

This month has become DC’s first wetter than average September since 2021. It will also finish more than a degree warmer than average. However, that obscures how changeable this month’s weather has been in the nation’s capital. 

Ten of the first 13 days of September were warmer than average in Washington, D.C. That includes highs in the 90s on the first four days of the month. September hadn’t had such a hot start to September since 2015. Although not quite record-setting, DC’s high of 98° on September 1 was DC’s hottest September temperature since it was 99° on September 5, 2023.

As hot as much of the first half of September was, the DMV (DC, Maryland and Virginia) saw a major shift in the weather pattern during the second half of the month. Washingtonians experienced eight consecutive cooler than average days through September 28. Measurable rainfall occurred on five of those eight days.

The nation’s capital will finish September 2026 with 4.26” of rain, compared to DC’s average of 3.93”. The wettest day was September 3 with 1.25” at National Airport. Following DC’s wetter than average August (4.27”), this month has given Washingtonians the first instance of consecutive rainier than average months since May and June of 2025.

The most memorable weather event this month was the early season Nor’easter that brought two days of measurable rainfall to the DMV on September 26-27. That also coincided with a stretch of cooler than average temperatures (eight days). Impacts in the DMV weren’t as significant as areas north and east of the nation’s capital, but were still significant. This was a long-lasting event that had far reaching impacts up and down the East Coast of the United States. Nor’easters are relatively rare events in September so it made headlines for a variety of reasons.

A closer look at Category 5 hurricanes

 

Hurricane Milton, October 2024 (Source: NOAA)

This season will become the first since 2021 that no Category 5 Atlantic hurricanes will develop. In fact, this season could become the first of the satellite era that no hurricanes of any intensity develop. That underscores just how active the 2022 – 2025 seasons were in the tropical Atlantic.

Melissa (2025): Once it reached hurricane status on October 25, Melissa underwent a period of rapid intensification. It ultimately finished tied as the third strongest Atlantic hurricane on record based on its lowest minimum air pressure of 892 millibars (mb). The lower the air pressure the stronger the storm is. Standard sea level air pressure is 1013 mb. Melissa’s peak sustained winds of 190 mph tied it for highest ever in an Atlantic hurricane. Unfortunately, it became the strongest hurricane to ever make landfall in Jamaica.

Humberto (2025): The second Category 5 of last season occurred in September, again over the open Atlantic. Humberto’s peak sustained winds were 160 mph. Its minimum central air pressure was 918 mb.

Erin (2025): The first Category 5 storm of last season developed in August and reached peak intensity over the open Atlantic. Its highest sustained winds were 160 mph and it’s lowest minimum central air pressure was 913 mb. Fortunately, Erin didn’t have any direct impacts on the United States.

Milton (2024): The second Category 5 hurricane of the season, Milton was also the strongest hurricane of 2024 with peak winds of 180 mph and a minimum central air pressure of 895 mb. Milton weakened to a still major 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.

Beryl (2024): Hurricane Beryl reached peak intensity on July 2 as only the second Category 5 storm to develop in the Atlantic in July. It highest sustained winds were 165 mph and its lowest minimum central air pressure was 932 mb. Beryl was the earliest Category 5 Atlantic hurricane on record.

Lee (2023): This was the strongest hurricane of a very active Atlantic hurricane season. At peak intensity, Lee had sustained winds of 165 mph and a minimum central air pressure of 926 mb. Lee had no direct impacts on the United States.

Ian (2022): Ian was the strongest hurricane of the season and first Category 5 Atlantic hurricane since 2019. At peak intensity, Ian had sustained winds of 160 mph and a minimum central air pressure of 937 mb. Fortunately, it weakened slightly to Category 4 status before its landfall in southwestern Florida. Ian became the third costliest hurricane in US history, having caused $119.6 billion in damages according to NOAA (2024 dollars).

A closer look at the Atlantic’s quietest hurricane seasons

 

Hurricane Chris, August 1994 (Source: NOAA)

The 2026 Atlantic hurricane season has already set a new record for latest in the season without a hurricane. The old record for delayed first hurricane was September 11. A little more than two months are left before the season ends on November 30.

Since September is the peak of the Atlantic hurricane season, tropical activity declines in October and November as conditions become less favorable for development. That said, this season could become the first in more than a hundred years without a single Atlantic hurricane. It’s estimated that no hurricanes developed during the 1907 and 1914 Atlantic hurricane seasons. However, those seasons occurred long before the satellite era began in the 1960s, so it’s possible a hurricane developed over the open ocean away from land or a nearby ship to detect it. 

What makes this season so potentially historic is that every hurricane season since the 1960s has featured at least one Atlantic hurricane. It remains possible that a hurricane will develop somewhere in the Atlantic before the end of the season. However, with only six short-lived tropical storms so far this season, the 2026 Atlantic hurricane season is well-positioned to finish as one of the quietest on record. Here are some of the other very quiet seasons since the 1980s.

1994: A total of only seven tropical storms developed this season with three that became hurricanes, but no major ones. What also stands out about this season is that two of the three hurricanes developed in November. The final month of the season, November is normally very quiet in the tropics.

1987: Another calm season with seven tropical storms, of which three became hurricanes. None made landfall in the United States. The strongest storm of the season was Category 3 Hurricane Emily.

1983: Similar to 2026, this season occurred during another very strong episode of El Nino and saw only four tropical storms with three hurricanes and one major hurricane. The major hurricane was “Alicia.” A Category 3 storm, Alicia developed off the Texas Gulf Coast where it made landfall. A “major” hurricane is defined as a Category 3 or greater on the Saffir-Simpson Hurricane Wind Scale with sustained winds of at least 111 mph around the storm’s center.

1982: Only six tropical storms developed during this season as well. Two intensified into hurricanes for lowest seasonal total of Atlantic hurricanes in the satellite era. The strongest storm was Hurricane Debby that reached Category 4 intensity over the north Atlantic Ocean.