NOAA’s National Centers for Environmental Information (NCEI) and the University of Colorado Boulder’s Cooperative Institute for Research In Environmental Science (CIRES) have released the upgraded High Definition Geomagnetic Model (HDGM) for 2026.
A global, high-resolution model of Earth’s geomagnetic field, the HDGM provides magnetic field values (total field, dip, and declination) at any point above or below the Earth’s surface. The HDGM is updated annually to correctly model changes in the geomagnetic field.
The new model has a 20% increase in resolution for more accurate subsurface mapping. It can now “see” magnetic variations caused by the Earth’s crust down to about 19 kilometers (12 miles) of detail. For the oil and gas industry in particular, this means ultra-precise guidance for drilling complex, billion-dollar wellbores, making operations safer and more efficient.
For example:
Safer Drilling in the Northern Polar Region: The Northern Lights (Aurora Borealis) are beautiful, but the powerful electric currents that cause them (the auroral electrojet) can severely disrupt magnetic measurements, throwing off drill guidance in places like Alaska and the North Sea. The 2026 update includes real-time disturbance correction for these high-altitude regions, protecting operators from magnetic storms.
Accuracy Everywhere: The model is not just better near the poles. Updates to the ionospheric modeling mean better accuracy in low and mid-latitude regions around the world. Plus, the core field model has been updated with the very latest satellite data to ensure it remains precise through the end of 2026.
![The World Magnetic Model is a large-scale representation of Earth’s magnetic field. The blue and red lines indicate the positive and negative difference between where a compass points the compass direction and geographic North. Green lines indicate zero degrees of declination. [Image credit: NOAA]](https://www.guiceoffshore.com/wp-content/uploads/2026/02/IMAGE-nesdis_wmm_image_draft4-123115-967x716-landscape.jpg-300x222.webp)
“Imagine a giant, invisible force field protecting Earth—that’s our planet’s magnetic field,” explains NOAA’s National Centers for Environmental Information. It guides the compass, produces the dazzling aurora, and, critically, guides directional drillers deep beneath the surface. This field is complex and constantly changing, and we need precise models to navigate it.”
What is the HDGM?
Scientists measure the geomagnetic field in the air (satellites and aircrafts) and on land (ground observatories) because they capture different parts of the field—from the vast, stable core-generated field to smaller crustal variations—all crucial for understanding space weather, navigation, resource exploration, and Earth’s deep processes. Satellites offer broad global coverage, while ground stations and low-flying aircraft map localized, detailed magnetic anomalies in the crust, providing complementary data.
NOAA and CIRES scientists combine satellite and ground-based data with airborne and marine magnetic data, which are compiled into the Earth Magnetic Anomaly Grid (EMAG2). This combination allows scientists to create the HDGM, which provides highly accurate estimates of the Earth’s magnetic field and its fluctuations over time. Consequently, the HDGM is recognized as the most advanced model for tracking changes in the global magnetic field.
As the data center for NOAA’s marine trackline geophysical data, NCEI is in a unique position to continuously enhance the resolution of the crustal magnetic field. The HDGM 2026 release signifies a major advancement in both resolution and real-time capabilities.
NOAA/British Geological Survey Release 2025 World Magnetic Model Report
The NCEI, together with the British Geological Survey released a joint Technical Report for the 2025 World Magnetic Model (WMM 2025), which is the standard navigation model for the U.S. Department of Defense and the global public which provides critical global data for navigation systems on ships, aircraft, satellites, antennas and even handheld smartphones and GPS devices.
In terms of military applications, the WMM proves indispensable for undersea and aircraft navigation as well as parachute deployment, antenna tracking, iceberg drift determination, and many other activities. In the private sector, the model can be found in virtually every smartphone. The Federal Aviation Administration also uses it to rename airport runways so that they accurately reflect their magnetic heading to allow for greater clarity during landing procedures.
Updated in December 2025, the WMM provides accurate declination, which is the difference between true north and Earth’s magnetic north. The WMM is revised every five years to ensure that navigational instruments continue to provide correct readings as Earth’s magnetic field shifts over time.
“The WMM provides critical information about the Earth’s magnetic field, which is the foundation for safe and reliable navigation for military and civilian applications,” said Deke Arndt, Director of NOAA NCEI. “This model reflects NCEI’s commitment to transforming Earth system observations into scientific understanding and providing tools for the public good.”
For 2025, two versions of the model were updated and released. In addition to the WMM 2025 version, the release includes the first-ever WMM 2025 High Resolution model, which provides greater directional accuracy for heading systems that are able to support this higher-resolution version.
“Both the standard and high-resolution models provide crucial magnetic field data that enhance global positioning systems,” said Arnaud Chulliat, CIRES senior research scientist for NOAA NCEI. “Satellite GPS is an important tool for determining your location, but knowing your orientation– the direction you are facing–relies on Earth’s magnetic field.”
The report also assesses the performance of the newly developed World Magnetic Model High Resolution (WMMHR2025). Comparisons between the predictions of the two models and recent data collected from the European Space Agency (ESA)’s Swarm satellites indicate that WMM2025 and WMMHR2025 have proven in their first year of operation to be accurate models.
Most of our planet’s magnetism originates from the shifting of electrically charged molten metals in its outer core, the behavior of which is unpredictable. An example of the secular changes that these metals can cause is the slow drifting of Earth’s magnetic north pole towards Siberia, a process that has been occurring continuously for the past few decades. As the WMM is predictive in nature, it becomes less accurate over time and must be updated with the newest projections derived from more recently collected data. Updates are scheduled to occur every five years.
This year’s report contains discussions of the two magnetic poles and their drift speeds. Over the past year, the northern magnetic pole has been traveling at a much faster rate than the southern pole with their average drift speeds measuring 36 km/year and 9 km/year, respectively. The actual locations and drift speeds of the magnetic poles proved to be very close to those predicted by WMM2025 and WMMHR2025, lending further credence to the overall accuracy of the models.
The South Atlantic Anomaly Grows
Also described in the State of the Magnetic Field Report is the deepening of the South Atlantic Anomaly (SAA), an area spanning the South Atlantic Ocean and South America where the Earth’s magnetism is weakest. This area is known to cause radiation damage to satellites and problems with radio propagation, issues that are exacerbated by the SAA’s growth in size by eight percent over the past year. NCEI continues to monitor the situation closely.
A well-known limitation of the WMM is the tendency for its accuracy to drop during magnetic storms, of which there were 18 that were strong to severe between November 1, 2023 to October 31, 2025. These space weather events can cause disparities between actual magnetic declination and the estimated declination provided by the WMM that are temporarily greater than the model uncertainty, especially at high latitudes. Such disparities can potentially affect navigation that relies on WMM2025 and WMMHR2025’s declination estimates. This year’s report includes descriptions of the two largest storms in order to alert users to this limitation to the models. Although Solar Cycle 25 has already passed its peak, space weather activity is expected to remain elevated for the next few years before gradually declining toward the anticipated solar minimum around 2030. Fortunately, the models take space weather into account in their error estimates.
Regardless of these minor concerns, all data gathered for the annual report indicates that WMM2025 and WMMHR2025 have operated well below the margin of error stipulated by the U.S. Department of Defense. The models can thus continue to be relied on by all technology that implements them.
Learn more about the WMM and geomagnetic models from NOAA NCEI