It’s actually been way overdue. About 70,000 years.
“(The poles also weakened temporarily and rapidly about 41,000 years ago)”....but didn’t flip.
Is Earth’s Magnetic Field Flipping Soon?
https://www.space.com/43173-earth-magnetic-field-flips-when.html
“The chief cause of the movement comes from the Earth’s liquid-iron outer core, which is also called the “core field.” Smaller factors also affect the movement. Those influences include magnetic minerals in the crust and upper mantle (especially for local magnetic fields) and electric currents created by seawater moving through an “ambient magnetic field,” according to the 2015 report of the WMM.
“One of the reasons we can update the map is that the European Space Agency launched a set of highly accurate magnetic-field satellites in 2013,” said Beggan, referring to Swarm.
What’s more, the core field appears to be weakening — which may be a sign that the planet’s magnetic field will flip. To better understand how that would happen, here’s how the core field works, according to Ronald Merrill, an emeritus professor of Earth and space sciences at the University of Washington, who spoke to Space.com’s sister site Live Science.
One easy way to imagine the field is to think of a bar magnet that runs through Earth’s center and has a north pole and a south pole, said Merrill, who was not involved in the new WMM research. That magnet is strong, representing roughly 75 percent of the intensity of Earth’s magnetic field at the surface.
Of course, a bar magnet is not a perfect representation — it’s actually electric currents that generate the Earth’s magnetic field — but the model makes it easier to imagine what’s happening to Earth, Merrill added. Specifically, the “bar magnet” is not only moving, but also getting weaker, by roughly 7 percent every 100 years.
As for the other 25 percent of the magnetic field, Merrill said that’s generated from another field, which you can picture as another moving bar magnet. Here’s an interesting bit: As the central bar magnet loses intensity, this second, weaker magnetic field generates more influence on Earth’s global magnetism. “And that’s what’s causing this field to move in the direction [of Siberia],” Merrill told Live Science.”
“Earth’s north and south poles periodically swap locations, with the last flip happening about 780,000 years ago. (The poles also weakened temporarily and rapidly about 41,000 years ago, Beggan added, but never underwent a full flip.)) A 2018 study in the journal Proceedings of the National Academy of Sciences suggested that Earth’s magnetic field got weaker before the big changeover.”
I don’t think that 780,000 years ago for the last flip is correct per my memory from previous articles, but its been a few years since I read about this and my old memory is not as good as it once was.