Full Breakdown
Northern Lights Expected Over Parts of the U.S. and Canada on July 21-22, 2026
7/22/2026, 11:03:14 AM
Core Event: Minor Geomagnetic Storm Prompts Aurora Forecast
A small-scale G1 (minor) geomagnetic storm is expected to arrive late on July 21 and continue into July 22 as a fast solar-wind stream from a coronal hole reaches Earth. NOAA’s Space Weather Prediction Center (SWPC) projects that the storm could push the planetary K-index (Kp) to four on Tuesday and five on Wednesday, conditions that may make the aurora borealis visible well south of the usual polar zones.
Background & Context
The solar wind driving this event originates from a large, recurring coronal hole—an opening in the Sun’s magnetic field that allows high-speed particles to escape. Unlike a coronal mass ejection (CME), which can produce widespread, intense auroras, a coronal-hole high-speed stream (CH HSS) typically yields a more modest geomagnetic response. NOAA notes that the stream’s magnetic orientation will determine how efficiently it couples with Earth’s magnetic field, influencing the storm’s ultimate strength.
Data & Statistics
- Kp forecast: 4 on Tuesday, 5 on Wednesday (moderate storm level).
- Storm classification: G1 (minor) according to NOAA’s scale.
- Predicted viewline: Alaska, Montana, North Dakota, Minnesota, Maine, and northern portions of Washington, Idaho, Wisconsin, Michigan, New York, Vermont, and New Hampshire.
- Timing: Activity expected to rise late on July 21 and persist through the early hours of Wednesday, July 22.
- Substorm potential: A co-rotating interaction region (CIR) accompanying the CH HSS could generate brief, brighter substorms that momentarily expand the auroral oval farther south.
Official Statements & Responses
NASA’s Solar Dynamics Observatory captured imagery of the coronal hole aimed directly at Earth, confirming the source of the high-speed solar wind.
Why It Matters
A G1 storm can push the auroral oval far enough south to be seen from populated northern-state locations, offering a rare summer viewing opportunity. While auroras during minor storms are often faint, clear, dark skies can reveal green ribbons or wavering curtains near the horizon. Substorms associated with the CIR may produce brief bursts of brighter light, further enhancing visibility.
On-the-Ground Guidance
- Optimal viewing window: Late-night hours, roughly 10 p.m. to 2 a.m. local time, though July’s short nights may limit the window.
- Location tips: Travel northward to a high, north-facing site away from city lights; avoid light pollution.
- Weather considerations: Cloud-free skies are essential; check local forecasts before heading out.
- Photography advice: Use night mode on iPhones or Pro mode on Android devices, disable flash, shoot in RAW, and mount the phone on a tripod. For dedicated cameras, set the aperture to f/4 or lower and focus to infinity, also using a tripod for stability.
Conflicting Reports & Gaps
NOAA acknowledges uncertainty in the exact arrival time and intensity because coronal-hole streams do not always reach Earth as predicted. The agency’s forecasts note that the storm’s impact will depend on the solar wind’s magnetic orientation, a factor that cannot be precisely known in advance. No other agencies have provided differing numerical forecasts, so the primary gap remains the timing and strength of the auroral display.
What’s Next
NOAA recommends monitoring its 30-minute aurora forecast and space-weather apps throughout the night of July 21-22 for real-time updates on solar-wind conditions and auroral activity.
