Space weather today in Anchorage, AK

Space weather in Anchorage today

G1 minor geomagnetic storm forecast (NOAA, 2026-11-06 01:40 UTC). The planetary Kp index is 2.3 now and forecast to peak at Kp 5 in the next 24 hours. NOAA gives a 35% chance of R1–R2 radio blackouts today, 10% for R3 or stronger, and 5% for a solar radiation storm.

Radio: solar flares only black out HF radio on the half of Earth facing the Sun. The Sun is 1° below the horizon in Anchorage now (4:51 pm local time). The biggest flare in the past 24 hours was M3.5 at 9:33 am local time, while Anchorage was in daylight, so HF radio here may have faded briefly. HF radio fades here during geomagnetic storms and solar radiation storms (polar cap absorption at S1+).

GPS and power: GPS and satellite signals here are among the first affected: during G2+ storms the aurora overhead can add metres of error and brief loss of lock. Long power lines at this latitude see geomagnetically induced currents from G3 storms upward; operators get NOAA warnings.

Aurora chance tonight in Anchorage

Good chance tonight: Kp 3.7 forecast, clear skies all night, look north and overhead. At 61.9° N geomagnetic, Anchorage needs about Kp 1 for aurora low on the northern horizon.

At the forecast Kp 5, the aurora's visible edge reaches Anchorage.

NOAA 3-day space weather forecast

Chances that NOAA issues each level somewhere on Earth. Radio blackouts only affect the sunlit side; geomagnetic storms are global but strongest near the poles.

Strongest solar flares this week

C-class and stronger flares from the past 7 days, local time in Anchorage.

• M3.5 flare peak Thu 9:33 am, R1 minor radio blackout
• C2.9 flare peak Thu 12:34 pm
• C2.5 flare peak Thu 3:24 pm
• C2.2 flare peak Wed 8:34 am
• C1.3 flare peak Thu 1:31 pm
• C1.2 flare peak Thu 1:21 pm
• C1.2 flare peak Tue 9:54 pm
• C1.1 flare peak Thu 8:00 am
• C1.1 flare peak Tue 1:39 pm
• C1.1 flare peak Sun 3:36 am

What the scales mean

Space weather is the Sun's effect on Earth. NOAA rates it on three 1–5 scales. R (radio blackouts) comes from solar flares: X-rays reach Earth in 8 minutes and disrupt HF radio on the sunlit side for minutes to hours. S (solar radiation storms) comes from energetic protons a few hours later, a hazard for satellites, polar flights and astronauts. G (geomagnetic storms) comes 1–3 days after a coronal mass ejection or a fast solar-wind stream hits the magnetic field: it drives the aurora and can upset GPS, HF radio and power grids.

The Kp index (0–9) measures geomagnetic activity in 3-hour blocks: Kp 5 is a G1 storm, Kp 6 G2, Kp 7 G3, Kp 8 G4 and Kp 9 G5. Flares are classed A, B, C, M and X by peak X-ray brightness, each class ten times the one before; M1 flares cause R1 blackouts and X1 flares R3.

Space weather for nearby cities

• Space weather Fairbanks
• Space weather Whitehorse
• Space weather Juneau

More sky pages

• Space weather today (worldwide)
• Northern lights tonight in Anchorage
• Aurora forecast
• Meteor showers

Guides

• Solar Flares and Geomagnetic Storms Explained: R, S and G Scales
• What Kp Index Do You Need to See the Northern Lights?
• How to See the Northern Lights Tonight: A Practical Guide
• GPS Jamming and Spoofing Explained: How Maps Detect It