Geomagnetic Storms Today: Live Forecast and K-index Levels (July 2026)
NOW: Kp 2 — Quiet ↑MAX: 2.2 ↓MIN: 1
NOW: Kp 2 — Quiet ↑MAX: 2.2 ↓MIN: 1
Geomagnetic storms today and current K-index levels — up-to-date data from NOAA, NASA, and other official space weather sources. This live geomagnetic storm forecast — also commonly searched as a magnetic storm forecast — and geomagnetic activity tracker is updated in real time.
What Is a Geomagnetic Storm
A geomagnetic storm — often called a magnetic storm in everyday language, and occasionally nicknamed a "geostorm" — is a disturbance of Earth's magnetic field. It happens when a coronal mass ejection (CME), a cloud of plasma ejected by the Sun, or a fast stream of solar wind reaches our planet. A solar flare arrives in 8 minutes; a geomagnetic storm today is usually the result of a slower, delayed event, since a CME typically takes 1–3 days to reach Earth after the eruption.
Because scientists can track the eruption on the Sun and estimate its speed and direction, they can issue a warning 1–3 days before the storm arrives — geomagnetic storms, unlike flares, can be forecast in advance. A magnetic storm today isn't always tied to a solar flare: a CME can occur without a major flare, and a powerful solar flare may have no ejection at all.
What Causes Geomagnetic Storms?
The primary triggers of geomagnetic storms are fascinating phenomena that originate from our Sun's dynamic activity. These powerful disturbances can be traced to several specific solar events:
- Coronal Mass Ejections (CMEs) - massive bursts of solar wind and magnetic fields released from the Sun's corona, carrying billions of tons of solar material into space at speeds reaching millions of miles per hour
- Solar flares - intense bursts of radiation from the Sun's surface that release enormous amounts of energy across the electromagnetic spectrum, from radio waves to X-rays and gamma rays
- High-speed solar wind streams emanating from coronal holes - these are regions in the Sun's atmosphere where magnetic field lines open into space, allowing solar wind to escape at particularly high velocities
Geomagnetic Storm Classification and Strength
NOAA classifies geomagnetic storms on the G-scale, from G1 to G5. Each level reflects an increasing strength of impact on Earth's magnetosphere:
- G1 (minor) — small fluctuations in power grids; auroras visible only at high latitudes near the poles
- G2 (moderate) — possible localized power supply issues; auroras shift closer to mid-high latitudes
- G3 (strong) — disruptions to satellite operation and navigation; auroras visible at mid-latitudes
- G4 (severe) — significant stress on power systems, possible outages; auroras visible far from the poles
- G5 (extreme) — an extremely rare event; risk of widespread power grid outages, transformer damage, and satellite disruptions. Example: the 1859 Carrington Event
Storm intensity is also reflected by the K-index (0–9) — the higher the value, the stronger the geomagnetic disturbance at that moment, and the more useful it is for reading a geomagnetic storm calendar of recent and upcoming activity at a glance.
G3-and-above storms, in addition to their effects on technology, may also have a possible effect on human wellbeing: on the days of such storms, weather-sensitive people often report headaches and migraines, blood pressure spikes, and sleep issues — while others, conversely, report a boost of energy and strength, increased creativity and inspiration.
The nature and intensity of the reaction is individual and depends on the strength of the specific storm. Understanding a storm's level helps you interpret the geomagnetic activity forecast more precisely and gauge how strong its effect on Earth will be.
Established Effects of Geomagnetic Storms on Earth
- Auroras. The stronger the storm, the farther from the poles the aurora can be seen — during G4–G5 events it's sometimes visible even at mid-latitudes.
- Power grids. Geomagnetically induced currents place extra stress on transformers and power lines, in rare cases leading to outages.
- Satellites and the ISS. The atmosphere expands during strong storms, increasing drag on low-orbit satellites and shortening their lifespan; operators adjust orbits and equipment modes accordingly.
- GPS and navigation. Satellite navigation accuracy can degrade noticeably during strong storms.
- Radio communication. Shortwave radio, especially in polar regions, can be disrupted for the duration of a storm.
Magnetic Storm Calendar
The magnetic storm calendar above displays live K-index readings as a continuously updating graph. It shows today's geomagnetic storm activity alongside recent history and any upcoming activity in one view, whether you're tracking storms for their technological impact or for their possible effect on your own wellbeing.
Protection and Preparation
Organizations and individuals can prepare for geomagnetic storms by:
- Monitoring space weather forecasts and alerts.
- Implementing backup systems for critical infrastructure.
- Following recommended safety protocols during severe storms.
- Having alternative communication methods ready.
Understanding and tracking geomagnetic storms is crucial for maintaining our technological infrastructure and protecting sensitive systems from potential damage.
Possible Effects of Geomagnetic Storms on Health and Wellbeing
Starting with the work of A.L. Chizhevsky in the 1930s (heliobiology), a large body of observations has accumulated: a number of statistical studies find a link between geomagnetic activity levels and the frequency of heart attacks, blood pressure spikes, sleep disturbances, and changes in wellbeing among weather-sensitive people. Proposed mechanisms include effects on melatonin and cortisol production, blood viscosity, and cryptochrome proteins that are sensitive to magnetic fields.
That's why we describe this as a possible effect: if you notice your wellbeing changing on days of geomagnetic storms, tracking that alongside the forecast is reasonable and safe. But this is an observation of correlation, not a diagnosis or medical advice.
Scientific Publications
- Myocardial infarct and geomagnetic disturbances: analysis of data on morbidity and mortality — https://pubmed.ncbi.nlm.nih.gov/9783069/
- Gaisenok et al. (2025). The Influence of Geomagnetic Storms on the Risks of Developing Myocardial Infarction, Acute Coronary Syndrome, and Stroke: Systematic Review and Meta-analysis. — https://pubmed.ncbi.nlm.nih.gov/40256184/
- Effect of Simulated Geomagnetic Activity on Myocardial Ischemia/Reperfusion Injury in Rats — https://pubmed.ncbi.nlm.nih.gov/31364342/
- Geomagnetic pulsations and myocardial infarctions — https://pubmed.ncbi.nlm.nih.gov/16821424/
- Exploring the Potential Observations Between Geomagnetic Activity and Cardiovascular Events: A Scoping Review — https://pmc.ncbi.nlm.nih.gov/articles/PMC12822803/
- The effect of geomagnetic activity on cardiovascular parameters — https://pubmed.ncbi.nlm.nih.gov/12653177/
- Geomagnetic disturbances reduce heart rate variability in the Normative Aging Study — https://pubmed.ncbi.nlm.nih.gov/35644403
- Synchronization of Human Autonomic Nervous System Rhythms with Geomagnetic Activity in Human Subjects — https://pubmed.ncbi.nlm.nih.gov/28703754/
- Exploring the relationship between geomagnetic activity and human heart rate variability — https://pubmed.ncbi.nlm.nih.gov/32306151/
- Long-Term Study of Heart Rate Variability Responses to Changes in the Solar and Geomagnetic Environment — https://pubmed.ncbi.nlm.nih.gov/29422633/
Live Geomagnetic Storm and K-index Forecast
Geomagnetic Storms: Full Archive
Une tempête géomagnétique peut-elle être prévue à l'avance ?
Oui. Contrairement à une éruption solaire, une tempête géomagnétique peut être prévue 1 à 3 jours à l'avance — une fois qu'une éjection de plasma (CME) est détectée sur le Soleil, les spécialistes estiment sa vitesse et sa trajectoire.
Une tempête géomagnétique et une éruption solaire sont-elles la même chose ?
Non. Une éruption est un rayonnement qui arrive en 8 minutes. Une tempête géomagnétique est la réaction de la magnétosphère terrestre à une éjection de masse coronale (CME) qui arrive 1 à 3 jours plus tard.
Qu'est-ce que l'indice K ?
L'indice K est une échelle de 0 à 9 qui reflète l'intensité des perturbations géomagnétiques à un moment donné. Des valeurs de 5 et plus correspondent au déclenchement d'une tempête (G1 ou plus forte).
À quelle fréquence les tempêtes géomagnétiques se produisent-elles ?
La fréquence et la force des tempêtes sont directement liées à la phase du cycle solaire de 11 ans : les tempêtes fortes (G3 et plus) se produisent beaucoup plus souvent pendant le maximum solaire et la phase déclinante du cycle.
Où puis-je consulter les prévisions de tempête géomagnétique d'aujourd'hui ?
Une prévision actualisée de la tempête géomagnétique et la lecture de l'indice K sont disponibles dans l'application MeteoAgent et sont mises à jour en temps réel à partir des données du NOAA SWPC et de la NASA.
Une forte tempête géomagnétique est-elle attendue aujourd'hui ?
Cela dépend de l'activité solaire actuelle — consultez l'indice K en direct et les prévisions de tempête ci-dessus pour les tempêtes géomagnétiques d'aujourd'hui, car les tempêtes fortes (G3+) ne se produisent que lorsqu'une CME ou un flux de vent solaire à grande vitesse atteint activement la Terre.
D'où proviennent les données de MeteoAgent ?
Agrégées en temps réel à partir du NOAA SWPC, de la NASA et d'autres sources officielles de surveillance de la météo spatiale.