Q&A of the Day – Where Does 2025’s Persistent Saharan Dust Rank?
Each day I feature a listener question sent by one of these methods.
Email: brianmudd@iheartmedia.com
Social: @brianmuddradio
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Today’s entry: Submitted by Joel Malkin. He inquired as to where 2025’s persistent Saharan dust plume’s rank historically.
Bottom Line: While several weeks remain in this year’s hurricane season, it’s safe to say that with only nine named storms and four hurricanes to date, about half of what the preseason forecasts predicted, this year’s hurricane season will turn out to be far less active than the above average projections. It’s also safe to say that a significant reason why that will be the case is the impact of Saharan dust. The ultimate hurricane repellant has been persistent throughout this year’s hurricane season. So much so that current dust projections show that Saharan dust will not only continue through the month of October, but also into November – the last month of hurricane season.
As I’ve covered somewhat extensively in recent years the Saharan Air Layer, which generally moves between 5,000 and 15,000 feet above sea level, contains an average of 50% less moisture and produces ever-so-slightly cooler ocean temperatures. The dust reflects some sunlight and reflects small amounts of solar radiation which can lead to slightly cooler ocean temperatures than otherwise would be when the dust is present.
Most notably, recent studies have shown that Saharan dust has become the single biggest factor in whether tropical formation takes place and how much rain is concentrated in storms that do form. With that info as the backdrop let’s dive into the research about how unusual this year’s Saharan dust pattern has been.
It’s not necessarily unusual for Saharan dust plumes to continue to kick up into the month of October. The normal window for the trans-Atlantic Saharan dust season is May through October. What is unusual is for Saharan dust to continue to make its way across the entire Atlantic.
Typically, Saharan dust plumes crossing the mid-Atlantic end in late July or early August leading to what are typically the four most active weeks of hurricane season – the last two weeks of August and first two weeks of September. Not only is Saharan dust still making its way across the Atlantic into the Caribbean, it appears likely to continue into November.
When researching the Saharan Air Layer there are a couple of important timelines. There isn’t measurable information to compare prior to the advent of the satellite age in 1966. Additionally advances in satellite tracking for Saharan dust specifically, were achieved in 2000. So historical comparisons are all based on dates from 1966 through 2025 – with the best data that’s been available over the past 25 years. Here’s what we know.
These are the years that included trans-Atlantic Saharan dust activity as late as November:
- 2021, 2020, 2016, 2008, 2006, 1983, 1972
So should Saharan dust continue across the Atlantic in November as is now expected it will become just the 8th year out of the past 59 to have experienced that much activity. However, for even greater context about where this season could land, here’s another factor to consider. Whether Saharan dust makes its way into the Gulf.
As we’ve seen in recent years, our greatest hurricane threats haven’t come from the Atlantic but rather from the Gulf. There are many factors that have played into why that’s been the case but one of them was the lack of Saharan dust. Commonly the Saharan dust that had made its way across the Atlantic didn’t continue into the Gulf. That’s been different this year. Most of the plumes (an average of two per week), have made their way not only across the Atlantic into the Caribbean but also into the Gulf of America. That’s far rarer.
Only twice do we have documented late season Saharan dust plumes having reached the Gulf – 2021 and 2008. That means 2025 is on pace to have one of three longest Saharan dust seasons in recorded history. Also of note, in 2008 there were 16 named storms and 8 hurricanes, and in 2021 there were 21 named storms and 7 hurricanes. We're on pace for far fewer storms and hurricanes than either of those years, meaning that it’s possible when all is said and done that this could be the most Saharan dust influenced hurricane season on record. Time will tell, but what’s certain is that what’s happened already has been historically unusual and what’s expected to continue from here is extremely rare.