In the days following Hurricane Harvey's devastating impact on the city of Houston and southeastern Texas in August 2017, many Facebook and Twitter users shared what appeared to be a curious pattern:
It's not clear what exactly these dates refer to, but they appear to be presented as the dates each hurricane made landfall in the United States. The Big Wobble web site specifically made this claim in a 31 August 2017 article with the headline: "Signs and wonders! Katrina, Gustav, Isaac and Harvey all made landfall on the 29th of August."
A 29 August 2017 Facebook post by Nola McKinley containing the meme was shared almost 400,000 times within two days.
The meme does not accurately state the date of first United States landfall for three of the four hurricanes it mentions. Depending on which time zone you use, the fourth date is also inaccurate.
There are a number of other issues with the viral spread of this meme, including: a U.S.-centric focus on the damage done by hurricanes in the United States, while ignoring the devastation they often first cause in the Caribbean; and a spurious search for numerical patterns in the midst of tragedy.
Here are the key dates leading up to landfall for each of the four hurricanes listed in the meme. All dates refer to events timed according to UTC (Coordinated Universal Time), which is four hours ahead of Eastern time, five ahead of Central time, seven ahead of Pacific time:
Katrina, 2005 (Source: National Hurricane Center)
- 23 August - Formed as a tropical depression over the Bahamas
- 24 August - Became Tropical Storm Katrina over the Bahamas
- 25 August - Reached hurricane status
- 25 August - Made landfall in Florida as a Category 1 hurricane (10.30pm UTC, 6.30pm EST)
- 26 August - Weakened to a Tropical Storm and moved over the Gulf of Mexico, quickly regained hurricane status
- 27 August - Strengthened to a Category 3 hurricane
- 28 August - Strengthened to a Category 5 hurricane
- 29 August - Weakened to a Category 3 hurricane, made second United States landfall near Buras, Louisiana (11.10am UTC, 7.10am EST)
Gustav, 2008 (Source: National Hurricane Center)
- 25 August - Formed as a tropical depression over the Caribbean, 95 miles north of the Netherland Antilles
- 25 August - Became a tropical storm
- 26 August - Strengthened to a hurricane, made landfall in Haiti (6pm UTC, 2pm EST)
- 27 August - Weakened to a tropical storm
- 28 August - Moved over Jamaica as a tropical storm
- 29 August - Strengthened to a hurricane
- 30 August - Strengthened to a hurricane, moved over the Cayman Islands as a Category 2 hurricane
- 30 August - Strengthened to a Category 4 hurricane, made landfall in Cuba (6pm UTC, 2pm EST)
- 31 August - Weakened over the Gulf of Mexico
- 1 September - made landfall near Cocodrie, Louisiana as a Category 2 hurricane (3pm UTC, 11am EST)
Isaac, 2012 (Source: National Hurricane Center)
- 21 August - Formed as a tropical depression over the Caribbean, 625 nautical miles east of the Lower Antilles, strengthened to a tropical storm
- 22/23 August - Moved over the Leeward Islands, between Guadeloupe and Dominica, and over the Virgin Islands
- 25 August - Made landfall in Haiti as a tropical storm (6am UTC, 2am EST)
- 25 August - Made landfall in Cuba (3pm UTC, 11am EST)
- 27 August - Moved over the Gulf of Mexico
- 28 August - Strengthened to a hurricane over the Gulf of Mexico
- 28/29 August - Made landfall at Southwest Pass on the mouth of the Mississippi River, Louisiana (12am UTC 29 August, 8pm EST 28 August)
- 29 August - Moved back over water before making second landfall near Port Fourchon, Louisiana (8am UTC, 4am EST)
- 17 August - Low pressure disturbance in the Caribbean (3pm UTC, 11am EST)
- 17 August - Strengthened to a tropical storm, 250 miles east of Barbados (9pm UTC, 5pm EST)
- 19 August - Weakened to a tropical depression (9pm UTC, 5pm EST)
- 23/24 August - Strengthened to a tropical storm (4am UTC, 12am EST, 11pm Central 23 August)
- 24 August - Strengthened to a Category 1 hurricane (5pm UTC, 1pm EST)
- 25 August - Strengthened to a Category 2 hurricane (5am UTC, 1am EST)
- 25 August - Strengthened to a Category 3 hurricane (7pm UTC, 3pm EST)
- 25 August - Strengthened to a Category 4 hurricane (11pm UTC, 7pm EST)
- 25/26 August - Made landfall on the coast of Texas at San Jose island, just east of Rockport as a Category 4 hurricane (3am UTC 26 August, 11pm EST 25 August)
- 26 August - Made second landfall at Copano Bay, Texas as a Category 3 hurricane (6am UTC, 2am EST)
- 30 August - Made third landfall near Cameron, Louisiana as a Tropical Storm (9am UTC, 5am EST)
So if we're looking at the first United States landfall of these four hurricanes, here's how the meme should look:
If we follow Coordinated Universal Time (UTC), only one of these four hurricanes made its first United States landfall on 29 August (Isaac in 2012).
However, if we follow Eastern time, Isaac's landfall happened on 28 August, and Harvey's first landfall happened on 25 August. Either way, none of these four hurricanes shared a United States landfall date with any of the others, undermining the premise of the viral meme.
Hurricanes are not one-off events that take place on a single date. They are phenomena that evolve, develop, strengthen and weaken, moving over and making landfall at various geographic locations over the course of days and weeks. That makes it easy to cherry pick dates to form a "pattern."
The search for patterns
It's not clear whether those posting and sharing the "8/29" meme are simply pointing out a curious coincidence (even though, as we've shown, the dates are wrong), or suggesting that there is some conspiracy (supernatural or man-made) behind them.
Let's imagine all these hurricanes did make their first United States landfall on 29 August. What would that mean?
Firstly, it would not necessarily be particularly strange. Late August and early September is peak hurricane season in the Atlantic. While all four highlighted hurricanes did not make their first U.S. landfall on the same date, they did each occur within the same eight-day period, between 25 August and 1 September.
Secondly, it would not be an example of government geoengineering or climate engineering. Conspiracy theorists have already claimed that Hurricane Harvey is "the latest example of covert weather warfare being waged on completely unsuspecting populations...orchestrated and manipulated by an ever more desperate and aggressive global power structure."
And some have claimed that the "8/29" date pattern in the meme is a clear sign of sinister government orchestration. Setting aside the fact that the dates are wrong, it is unclear why the U.S. government would choose to schedule the United States landfall of four hurricanes for the same calendar date across 12 years, or how this would even be possible. If the supposed purpose of climate engineering is to wage "weather warfare" against "unsuspecting populations," why would the purported conspirators continuously choose the same date?
There is a pattern behind the dates of these four hurricanes - they all made their first United States landfall within an eight-day period, in different years. But this has a very simple and boring explanation: 25 August-1 September is part of peak hurricane season in the Atlantic.
Any interpretation of hurricane dates that goes beyond this is entirely spurious, requiring as it does ludicrous government conspiracy theories or supernatural predetermination. However, the desire to find numerical patterns and explanations in the midst of terrible human tragedy, such as that brought by Hurricane Harvey, is a very understandable one.
We saw similar spurious memes about the dates of terrorist attacks in the aftermath of the 22nd May 2017 suicide bombing at an arena in Manchester, England. Faced with the horror of dozens of children being slaughtered at a pop concert, many found comfort or distraction in pointing out a supposed pattern of terrorist attacks on the 22nd day of various months. In reality, a terrorist attack is no more likely to happen on the 22nd than any other day of the month.