The Atlantic Hurricane Season Doesn't Start Until June. Recent History Has Proved Otherwise.

The Atlantic hurricane season begins in June, but recent years have shown storms don’t necessarily wait until the first of the month.

Last year, we almost had the season’s first tropical storm a week before Memorial Day.

A small area of low pressure produced 40- to 60-mph wind gusts along the northern Gulf Coast.

We've had a string of storms before June. From 2015 through 2021, at least one named storm formed in the Atlantic Basin prior to June in each of those seven years. You can see their tracks plotted on the map below.

And on May 11, the National Hurricane Center announced their post-analysis revealed a subtropical storm formed off the U.S. East Coast this past January. So, technically, the 2023 hurricane season has already had its first storm.

Some of those preseason storms were impactful. While some of these storms were short-lived and far from land, at least 20 deaths and about 200 million dollars in damage can be attributed to May storms since 2012, according to the World Meteorological Organization.

In 2016, Tropical Storm Bonnie soaked the coast of the Carolinas in late May. That was preceded by eastern Atlantic Hurricane Alex, only the second known January Atlantic hurricane. Alex eventually made landfall in the Azores as a tropical storm.

In 2012, Tropical Storm Beryl almost reached hurricane strength before landfall on Memorial Day weekend in northeast Florida.

Here’s how the hurricane season’s start and end were selected. Officially, the Atlantic hurricane season runs from June 1 through Nov. 30. That time frame encompasses 96% of all Atlantic tropical storms and hurricanes, according to NOAA's Hurricane Research Division.

In 1935, the season was set from June 15 through November 15 to match up with a special telegraph line connecting the various centers of the U.S. Weather Bureau, according to NOAA-HRD. In 1964 and 1965, those start and end dates were adjusted to June 1 through November 30. They've been the same ever since.

Here’s what the National Hurricane Center is doing now. No changes have yet been made to the official start, or end, dates of hurricane season.

"​In 2021, the National Weather Service assembled a team to determine quantitative thresholds for adding or removing dates from the official Atlantic hurricane season, along with an examination of the potential ramifications of moving the beginning of hurricane season to May 15," said Maria Torres, a meteorologist and communications and public affairs office at the National Hurricane Center in an email to weather.com.

Torres said the team found moving the start date two weeks earlier would add only 1 percent of activity. She also noted the rarity of May storms to become hurricanes, the last of which occurred in 1970 (Hurricane Alma).

However, beginning in 2021, the National Hurricane Center moved up the date at which they begin issuing their Atlantic tropical weather outlooks to May 15 to cover these potential preseason storms. These outlooks issued four times each day show areas where tropical development is possible over the next seven days.

Preseason storms can’t predict the season. We examined all hurricane seasons in the satellite era – from 1966 through 2022 – parsing out whether or not they produced at least one storm before June 1.

As you might expect, the 17 seasons with at least one pre-June 1 named storm ended up with an average of three to four more storms for the season than the 39 seasons without a preseason storm.

However, the number of hurricanes and major hurricanes (Category 3 or stronger) were virtually the same in seasons that started early compared to those that did not. This is because the overwhelming majority of both hurricanes and major hurricanes occur in the peak months of August through October.

So there's little useful information we can take away from the presence or lack of a pre-June 1 storm for the hurricane season.

Now is a good time to develop or refresh your hurricane plan well before the season's first hurricane.

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