What September during past powerful El Niños looked like
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We looked at past El Niños on their way to 'super status' to find out what September may offer in the U.S. and tropics.

Jonathan Erdman
ByJonathan Erdman
August 28, 2026Updated: August 28, 2026, 2:24 pm EDTPublished: August 26, 2026, 8:00 pm EDT

How a strengthening El Niño typically shapes September weather

September in the U.S. might take on some weather themes seen during past intensifying El Niños, including impacts on temperatures, rainfall and what's typically the Atlantic hurricane season's peak month.

As we've hit on since last spring, this still-strengthening El Niño could be a record-setter by later this year. While it's not the only impact on weather, it will probably exert a significant influence in September.

So what could this mean for you?

We examined the six previous El Niños since 1950 that eventually reached "super" status. While that doesn't mean it may hold true this September, here's what those past Septembers have looked like.

Who could be hot

As the map below shows, taking the six past super El Niños together:

  • The Southern and Central Plains into the Northeast tend to be warmer than average.
  • Much of the western and northwestern U.S. tends to be cooler than average.

However, during the last bullish El Niño in 2015, America had its second hottest September in 121 years, according to NOAA.

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Nine states — Colorado, Connecticut, Maine, Michigan, Minnesota, New Mexico, Rhode Island, Utah, Wisconsin — had their hottest September in 2015.

September temperatures in super El Niño years

This map shows the departure from average September temperatures in the U.S. during six prior El Niños that eventually reached super status.

(NOAA/PSL)

Who could be wet or dry

Similarly, for September precipitation during those past six eventual super El Niños:

  • Much of the East and South trends drier than average.
  • Much of Midwest and West tends to be wetter than average.
September precipitation in super El Niño years

This map shows the departure from average September precipitation in the U.S. during six prior El Niños that eventually reached super status.

(NOAA/PSL)

The combination of a hotter, drier September could make the Plains drought worse this year.

That's exactly what happened in the last bullish El Niño 11 years ago. A hot, dry September both spread and worsened the drought from Texas to Mississippi, as the animation below shows.

Drought worsening during 2015 El Niño

This animation shows the Drought Monitor analysis in late August, then early October 2015. The arrows denote the parts of the Southern Plains and lower Mississippi Valley where drought conditions spread and worsened after September 2015.

(USDA/NDMC/NOAA)

Hurricane season squashing?

September is typically the peak month of the Atlantic hurricane season.

But it typically takes a haircut during stronger El Niños.

The six past Septembers during eventual super El Niños averaged about half the named storms. Each of those six past Septembers had only one Atlantic hurricane form, 1 to 2 fewer than usual.

September El Niño Atlantic hurricane season

The mean number of storms, hurricanes and Category 3 or stronger hurricanes that occurred during six previous soon-to-be super El Niño Atlantic hurricane seasons compared to the 1991-2020 September average.

(Data: NOAA/NHC)

Then there are the tracks.

Except for a flirting with the East Coast from 1972's Hurricane Dawn, all other September hurricanes during what would become super El Niños stayed well out in the Atlantic.

But there was one exception.

Joaquin first became a tropical storm, then hurricane in September 2015, then stalled and clobbered over the central Bahamas in early October, leaving catastrophic damage in its wake.

September Atlantic hurricane season tracks during future super El Niños since 1950

This map shows tracks of all September Atlantic Basin storms and hurricanes that formed during what would eventually become super El Niños. A few of the notable storms, including those close to the U.S. are labeled.

(Data: NOAA/NHC)

As with investments, the past doesn't guarantee this September will look exactly like that.

But it does offer an interesting look at what could happen.

Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him on Bluesky, X (formerly Twitter) and Facebook.

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