X1.0 Solar Flare: G3 Geomagnetic Storm Could Bring Northern Lights to Europe and the U.S.

A powerful eruption on the Sun has put space weather back in the spotlight. Active Region 4455 produced a series of strong solar flares on June 3, including an X1.0 flare that triggered an R3 radio blackout on the sunlit side of Earth. NOAA‘s Space Weather Prediction Center is now watching multiple coronal mass ejections that may interact with Earth on June 4–5, with G3 geomagnetic storm levels possible.

What happened on the Sun?

On June 3, Active Region 4455 became the dominant source of solar activity. The region produced several strong flares in a short period, including M-class events and then a stronger X1.0 solar flare. X-class flares are the most powerful category of solar flares, and even a low-end X-class event can create noticeable effects in Earth’s ionosphere.

The X1.0 flare peaked at 11:28 UTC on June 3. The event began at 11:19 UTC and ended at 11:35 UTC. It produced an R3 — Strong radio blackout — on the sunlit side of Earth. R3 events can cause wide-area degradation or blackout of high-frequency radio communication for about an hour, especially near the sub-solar region at the time of the flare.

The flare itself reached Earth almost immediately as electromagnetic radiation. The larger concern now is the coronal mass ejection activity associated with the flare sequence. CMEs are clouds of plasma and magnetic field that take much longer to travel from the Sun to Earth, but they can drive geomagnetic storms when they arrive.

Why this solar event matters

This is not only about one flare. Region 4455 produced multiple significant eruptions, and at least some CME components appear to be Earth-directed or glancing toward Earth. NOAA/SWPC has issued a G3 geomagnetic storm watch for June 4–5 UTC because several CMEs may combine or interact on the way to Earth.

When multiple CMEs leave the Sun close together, the timing becomes more uncertain. A later and faster CME can catch up with an earlier one, compressing the solar wind structure and strengthening the geomagnetic response. That is why the forecast includes the possibility of G3 levels rather than only minor storming.

NOAA forecast: UTC timeline and storm level

The NOAA 3-day outlook, issued at 00:30 UTC on June 4, shows the greatest expected 3-hour Kp value reaching 7, which corresponds to a G3 — Strong geomagnetic storm. The most important forecast windows are from late June 4 UTC into June 5 UTC.

Europe timing: when to watch

For Europe, the most favorable timing is the evening of June 4 and the early hours of June 5. The first G3 window falls during evening hours for Western and Central Europe, while the second stronger modeled peak lands after midnight or before dawn depending on the country.

Best European aurora zones

The best viewing chances will be in Scandinavia, Iceland, the Faroe Islands, Scotland, northern Ireland, the Baltic states, northern Poland, northern Germany and northern Netherlands if the storm reaches G3 during darkness. Farther south — France, Czechia, Austria, Switzerland, Hungary, Romania, northern Italy and the Balkans — visible aurora is less likely, but a camera may catch a faint red or purple glow if the storm overperforms.

United States timing: when to watch

For the United States, NOAA’s update points to combined CME arrival around mid-afternoon EDT on June 4, with G3 levels possible afterward. That means the earliest storm response may begin during daylight for much of the country, but the best aurora opportunity may come Thursday evening into the night of June 4–5.

Best U.S. aurora zones

The best U.S. chances will be across Alaska, Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, northern Illinois, northern Indiana, northern Ohio, northern Pennsylvania, upstate New York, Vermont, New Hampshire and Maine. If the storm reaches full G3 strength and the solar wind orientation is favorable, aurora may extend farther south than usual, especially in cameras pointed toward the northern horizon.

What the Kp forecast map shows

The forecast map shows that the storm risk is not evenly spread across the entire period. The most important windows are separate 3-hour blocks where the Kp index rises into red values near Kp 7. Yellow and orange periods indicate elevated or moderate activity, but the red sector is the main signal for expanded aurora visibility and stronger technical impacts.

This kind of forecast should be read as a wave timeline. A CME can bring an initial shock, a main plasma cloud and then a longer disturbed solar-wind phase. Because of that, Kp can jump quickly from quiet values to G2 or G3, then drop again before another pulse arrives.

Could the northern lights be visible?

At G3 level, aurora can expand far south of its usual high-latitude zone. In Europe, northern countries have the highest chance, while central Europe may need a stronger-than-expected storm, clear skies and a dark northern horizon. In the United States, NOAA’s G3 scale notes that aurora has been seen as low as Illinois and Oregon during strong geomagnetic storms.

How to observe the aurora if the storm strengthens

Do not look overhead first. At middle latitudes, aurora often appears low in the northern sky. It may not look like the bright green curtains seen in Arctic photos. It can appear as a faint red, pink or purple glow, especially in long-exposure images.

Possible impacts of a G3 geomagnetic storm

For most people, a G3 geomagnetic storm does not mean that phones, internet or power will suddenly fail. The main impacts are more specialized: HF radio, satellite operations, navigation accuracy, aviation at high latitudes and power-system monitoring.

Health and sensitive people

Geomagnetic storms do not affect everyone in the same way. Many people feel nothing. Others may report fatigue, headache, poor sleep, irritability or pressure fluctuations during disturbed space-weather periods. People with cardiovascular conditions, chronic illness, severe stress or sleep problems should be more careful.

During June 4–5, it is sensible to reduce unnecessary overload, drink enough water, avoid excessive alcohol and caffeine, and try to get regular sleep. People taking prescribed medication should not change their treatment plan because of a geomagnetic storm without medical advice.

Could more solar flares happen?

Active Region 4455 remains magnetically complex, with mixed polarities and strong shear. Those conditions can support additional strong flares. NOAA’s 3-day forecast keeps the chance of R1–R2 radio blackouts elevated through June 6 and also lists a smaller chance of R3 or stronger events.

That means the forecast can still change. If Region 4455 or nearby active regions produce another Earth-directed CME, geomagnetic storm forecasts may need to be updated. Real-time NOAA/SWPC alerts remain the most important source for operational decisions.

Use Pogodnik to track weather and sky conditions

During a solar storm, the Kp forecast is only one part of the plan. Cloud cover, visibility, fog, rain and local light pollution decide whether an aurora can actually be seen. The Pogodnik app helps track hourly weather, cloudiness and storm conditions for your location, while space-weather updates help you understand when aurora chances increase.

If you are planning to watch the northern lights from Europe or the United States, check both the space-weather forecast and the local sky forecast. A G3 storm can be wasted under clouds, while a short clear window can make the difference between missing the event and capturing a rare mid-latitude aurora.

What this means now

The June 3 solar event is significant: Active Region 4455 produced several major flares, including an X1.0 event, and NOAA expects multiple CMEs to influence Earth on June 4–5. A G3 geomagnetic storm is possible, with expanded aurora chances for Europe and the United States, especially during local nighttime windows.

The forecast still depends on CME timing, speed and magnetic orientation. If the solar wind turns strongly southward, the storm can intensify. If the magnetic field is less favorable, the final impact may be weaker than the forecast peak. The best approach is to monitor real-time updates, check local cloud cover and be ready during the main evening and overnight windows.

FAQ: X1.0 solar flare, G3 geomagnetic storm and aurora forecast

What happened on June 3?

Active Region 4455 produced several strong solar flares, including an X1.0 flare at 11:28 UTC. The X-class flare caused R3 radio blackout conditions on the sunlit side of Earth.

When is the geomagnetic storm expected?

NOAA forecasts elevated geomagnetic activity on June 4–5 UTC, with the highest expected Kp reaching 7, which corresponds to a G3 storm.

When should Europe watch for aurora?

The most important windows are the evening of June 4 and the early hours of June 5. For Central Europe, the main G3 window is roughly 20:00–23:00 on June 4 and again around 02:00–05:00 on June 5.

When should the United States watch?

The best U.S. viewing window may be Thursday evening, June 4, especially from about 8–11 PM Eastern, 7–10 PM Central, 6–9 PM Mountain and 5–8 PM Pacific, with continued chances later if the storm persists.

Where could aurora be visible?

In Europe, the best chances are in Scandinavia, Iceland, Scotland, the Baltics and northern parts of Germany and Poland. In the U.S., the best chances are across the northern tier, Great Lakes, Upper Midwest, Northeast and Pacific Northwest.

Is a G3 geomagnetic storm dangerous?

For most people, it is not dangerous. The main concerns are technical: HF radio, satellite operations, navigation accuracy, power-system monitoring and high-latitude aviation.

Could new solar flares change the forecast?

Yes. Region 4455 remains active, and new Earth-directed eruptions could extend or strengthen geomagnetic storm conditions.

Geomagnetic Storm June 2026