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Aurora tonight: will you see the northern lights?

An automatic, plain-English read of NOAA's geomagnetic forecast for the next 24 hours, aimed at US viewers. Updated Wed Oct 21, 3:25 PM ET.

Minor storm level (G1) possible: an outside chance along the northern US border

At Kp 5, aurora is mainly a high-latitude event (Alaska, Canada). Our guide's rough rule is that the northern edge of the contiguous US usually needs Kp 6–7, so at Kp 5 a sighting there is an outside chance at best, low on the northern horizon from a very dark site.

Verdict basis: the higher of the current Kp and the highest Kp forecast for the next 24 hours (4.67), rounded to the nearest whole Kp step (NOAA counts Kp 4.67, written 5-, as G1), using the same rough latitude bands as our Kp index guide.

Kp now

3.33
Estimated value for the 3-hour block starting Wed Oct 21, 2:00 PM ET.

Highest Kp forecast, next 24 h

4.67
3-hour block starting Wed Oct 21, 5:00 PM ET. Kp 5 or more is a geomagnetic storm (G1+).

NOAA scales now

G0Geomagnetic storm
S0Radiation storm
R0Radio blackout
NOAA's predicted G level by day (UTC): 2026-10-21: G1 · 2026-10-22: G0 · 2026-10-23: G0

Kp forecast by 3-hour block (Eastern Time)

Wed 2 PM3.3estimated
Wed 5 PM4.7estimated
Wed 8 PM4.0predicted
Wed 11 PM3.7predicted
Thu 2 AM3.3predicted
Thu 5 AM2.0predicted
Thu 8 AM1.7predicted
Thu 11 AM2.0predicted
Thu 2 PM2.3predicted

Each block starts at the time shown and lasts 3 hours. "Observed" and "estimated" are measured values; "predicted" is NOAA's forecast. Data: NOAA SWPC planetary K-index forecast (U.S. government work, public domain).

Active NOAA alerts, warnings and watches

Our short summaries of NOAA SWPC products (U.S. government work, public domain); headlines quoted from NOAA. Read the full official text on the SWPC alerts page.

When and how to look

Look after full darkness, especially within an hour or two of local midnight, roughly 10 p.m. to 2 a.m. local time; strong storms can widen that window. In interior Alaska in winter, UAF suggests about 9 p.m. to 3 a.m. Face north, get away from city lights, and give your eyes 15–20 minutes to adapt. A phone camera on a long exposure often shows aurora that looks faint or grey to the eye.

Forecasts are uncertain. Kp forecasts are often wrong about timing and strength. Storms can arrive early, late, weaker or stronger than predicted, and short bursts (substorms) are not captured by a 3-hour average. Even with strong activity you need clear, dark skies: clouds, city lights and a bright moon can hide the aurora completely. This verdict is generated automatically from NOAA data using fixed rules, and is general information only. It is not an official forecast and not for safety or operational decisions. NOAA SWPC is the official U.S. source: see its 30-minute aurora forecast and 3-day forecast.

Learn more

Book a guided aurora tour

A guide does the driving, the forecast-watching and the hunt for clear skies, which helps most if you are visiting and don't know the area. A high Kp is only part of the picture: clear, dark skies decide most nights.

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Alaska

Tours are listed on Viator (a Tripadvisor company) and GetYourGuide. Latitudes are approximate. Durations, where shown, are approximate and come from the operators. Prices, availability and reviews change, so check them on the booking page.