Six storms were active in the Atlantic and Eastern Pacific basins, "which appears to have tied a record number of combined storms at once in those two areas," TWC said.
The storms were Humberto, Imelda, Jerry, Kiko, Lorena and Mario.
Humberto and Kiko were whirling in the Atlantic and Eastern Pacific. Imelda and Jerry were in the Atlantic basin while Mario and Lorena swirled in the Eastern Pacific.
"Anyone want a tropical storm? They are forming like roaches out there!" said Erin Blake, a scientist with the National Hurricane Center. "6 at once in both basins combined is thought to tie a modern NHC record , with two other disturbances adding the cherries on top of a crazy busy day!"
Blake added on Twitter that this combined number of active storms in both basins is believed to tie a modern record from September 1992.
According to the National Oceanic and Atmospheric Administration, September is a peak month for storm activity in both basins.
There have been as many as five active Atlantic tropical cyclones at once, which happened in September 1971, the National Hurricane Center said.
In addition, "there were five simultaneous named storms of at least tropical storm strength in the Eastern Pacific Basin east of the international date line" in August 1974, Phil Klotzbach, a tropical scientist at Colorado State University, told weather.com in 2015.