Northern Lights Alert: 26 States May See Aurora On July 4

The Northern Lights are expected to be visible overnight from July 3rd to 4th, potentially across up to 26 U.S. states, just before Independence Day celebrations. Multiple coronal mass ejections from the sun are heading towards Earth, possibly triggering G1 to G3-class geomagnetic storms. This could allow aurora sightings in northern states like Montana and Minnesota, and even as far south as Kansas or Maryland if a strong G3 storm materializes. However, the waning Strawberry Moon and long daylight hours may hinder visibility. Observers should look north around midnight, away from city lights, and consider using long-exposure camera settings. Real-time forecasts from NOAA and specialized apps can provide crucial updates on the interplanetary magnetic field's Bz component, which is key for aurora visibility.

The northern lights may be visible overnight in up to 26 states on the Fourth of July, hours before Independence Day celebrations in the U.S. They are expected to be visible overnight on Friday, July 3, through Saturday, July 4.

Heading for Earth are multiple coronal mass ejections, clouds of magnetic fields and charged particles from the sun that stream into space at up to 1,900 miles (3,000 kilometers) per second. A G1, G2 or even G3-class geomagnetic storm could result, causing aurora to be seen on the northern horizon from U.S. states close to the border with Canada — most likely across parts of Montana, North Dakota, Minnesota and northern Wisconsin — but potentially much farther south in northern and lower Midwest states.

The waning Strawberry Moon, in the southern sky after midnight, along with long daylight hours in the wake of last week’s solstice, may make aurora harder to see.

“A series of direct+glancing blows beginning on July 3rd could spark G2 to G3-class geomagnetic storms over the 4th of July holiday weekend,” according to SpaceWeather.com, especially in northern-tier US states.

According to a forecast by space weather experts at the National Oceanic and Atmospheric Administration, “G1-G2 conditions are likely by 03-04 Jul due to the anticipated arrival of the 30 Jun CME associated with the X1.1 flare”

A UK Met Office forecast suggests that a G3-class geomagnetic storm is possible. “Geomagnetic activity likely to reach Active to G1/minor geomagnetic storm (Kp 4-5) with a chance of isolated G2 Moderate storm (Kp 6) intervals, and a slight chance of G3 Strong storm (Kp 7), if the CME is more impactful than anticipated,” states the UK Met Office’s Space Weather forecast about July 3 in Universal Time — early on July 4 in North America. It also suggested that at least three CMEs that left the sun on July 1 could impact Earth on Sunday, July 5.

KP7 conditions can mean the northern lights are seen down to the lower half of the U.S. During a G2-level geomagnetic storm, northern parts of Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan and Maine. stand a chance. Also in with a shout are states farther south, including Oregon, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Pennsylvania, New York, Vermont and New Hampshire. If G3 storming materializes, those under dark skies in Kansas, Missouri, Kentucky, West Virginia, Virginia and Maryland may also see aurora.

If the skies are clear, aurora watchers should look north around midnight, avoid bright lights, and use long-exposure settings on their phones or cameras. Cameras often detect faint aurora before the human eye can see color clearly.

To check visibility in real time, use NOAA’s 30-minute aurora forecast or download apps such as Aurora Now, My Aurora Forecast or Glendale Aurora for up-to-the-minute alerts and live solar wind data.

Whether an aurora display materializes largely depends on the interplanetary magnetic field, specifically its Bz component (you’ll find it in some of the above apps and on SpaceWeatherLive.com). Bz determines how easily solar energy enters Earth’s magnetosphere. When Bz points north, Earth’s field resists it; when Bz swings south, the two fields connect, allowing plasma to stream in. A sustained southward Bz of −5 nT or stronger usually signals an imminent display of aurora.

Aurora sightings have become more common over the past two years because the sun reached the solar maximum phase of its 11-year solar cycle. It’s now in its declining phase, but sightings from areas south of the Arctic Circle are often limited to a faint glow low on the northern horizon.

For the best chance of seeing the northern lights, plan a trip between September and March to auroral latitudes around the Arctic Circle — roughly 65 to 70 degrees north — in Alaska, northern Canada or northern Scandinavia, including Norway, Finland, Sweden and Iceland. There, displays are typically more frequent, brighter and far more dramatic than anything possible in the U.S., sometimes spreading across the whole sky in a spectacle that can leave observers dumbstruck.