Northern Lights Tonight

You can see the northern lights tonight when NOAA’s Kp forecast for your dark hours reaches the Kp your spot needs. By NOAA’s rule the aurora’s edge sits near 66° magnetic latitude at Kp 0 and moves 2° toward the equator per Kp level: Fairbanks needs almost none, Minneapolis about 6+, New York 8+.

How to use it

Type your town, a place you are going, or a latitude and longitude, or press Use my location. The tool works out your magnetic latitude, the Kp you need, and when it is dark enough tonight (the Sun at least 12° below the horizon, the end of nautical twilight as the U.S. Naval Observatory defines it). Then it reads NOAA’s 3-day Kp forecast and answers for tonight and the next two nights, with the moon and the direction to face. Below the answer: the aurora destinations the forecast reaches, dark enough this month.

NOAA’s rule: Kp and how far south the aurora reaches

“The level of geomagnetic activity is indicated by the planetary K index or Kp.” NOAA’s Space Weather Prediction Center gives the rule this tool runs on: “At Kp = 0, the equator ward edge of the auroral oval is approximately 66 degrees.” “And it moves equatorward about 2 degrees for each level of Kp.” It “holds true in geomagnetic latitude, not geographic”, which is why Calgary, at 51° north, needs the same Kp as Stockholm at 59°: the magnetic pole sits over northern Canada. The pole here is the IGRF-14 model’s, the one NOAA publishes for the International Association of Geomagnetism and Aeronomy.

NOAA’s own words on what that looks like: “For Kp in the range 0 to 2, the aurora will be far north, quite dim in intensity, and not very active.” At Kp 6 to 7, “it might be possible to see the aurora from the northern edge of the United States”, and at 8 to 9, “aurora may be seen directly overhead from the northern states of the USA.” And a warning the tool repeats: “It should be noted that the relationship between Kp and auroral latitude are approximate and represent averages.”

The last two columns are NOAA’s Space Weather Scales page, for the storms (G1 at Kp 5 to G5 at Kp 9): how far from the pole the aurora “has been seen” at each level, and how many days each level brings in an average 11-year solar cycle. The two sources are two questions: the edge is where the aurora can be over your head; “seen as low as” is where someone saw it low in the sky. From Kp 7 up the second reaches farther, and the tool gives both.

Where to see the northern lights, and when it is dark there

The Kp each place needs by the rule, and its hours of darkness on the night of the 15th, computed for 2026:

Summer is the catch: “So combining a summer vacation to the arctic with aurora watching usually doesn’t work.” Longyearbyen has no dark hour in mid-September and almost a whole day of it in December. “The best Seasons for aurora watching are around the spring and fall equinoxes.” Read more in the best places in the world to see the northern lights, and plan the season with Iceland in summer vs. winter.

On the night

• “Go out at night.” “Get away from city lights.” A place from the darkest skies on Earth is the ideal; a dark road out of town will do.
• “Find a place where you can see to the north ( or south if you are in the southern hemisphere).” The tool says which way: toward your magnetic pole, north-northwest from Europe, north-northeast from Alaska.
• “Best aurora is usually within an hour or two of midnight (between 10 PM and 2 AM local time).”
• “The full moon will also diminish the apparent brightness of the aurora (not the actual brightness).” The tool gives the moon for each night.
• For the camera, photographing the northern lights without ruining the night.

Worked examples

Fairbanks, Alaska. Magnetic latitude 65.7°: the aurora’s edge is there at Kp 0+, so any dark, clear night can have it. In mid-December that is 15 hours of darkness; in June, none.

Minneapolis. Magnetic latitude 53.4°, so (66 − 53.4) ÷ 2 = 6.3: it needs Kp 6+, a G2 storm. A night with Kp 4 forecast is a no, the edge still about 320 miles north. At Kp 7 NOAA’s scale adds a chance low on the northern horizon.

New York City. Magnetic latitude 49.9°: Kp 8+ overhead, Kp 8 low on the horizon, a G4 storm. NOAA counts about 64 days at G4 or G5 in an 11-year cycle.

Atlanta. Magnetic latitude 42.7°: the edge never gets there, but at Kp 9 “aurora has been seen as low as Florida and southern Texas (typically 40° geomagnetic lat.)”, so the tool says Kp 9, low on the horizon.

London and Edinburgh. London is at 53.3° (Kp 6+), Edinburgh at 58.1° (Kp 4): a short train ride north halves the storm you need.

Common mistakes

• Reading latitude off a map. Magnetic latitude decides. Seattle and London are 4° apart on the globe but need almost the same Kp.
• Going in summer. The aurora is there; the dark is not. “The aurora is not visible during daylight hours.”
• Waiting for overhead. “The aurora does not need to be directly overhead but can be observed from as much as a 1000 km away when the aurora is bright and if conditions are right.” The rule’s number is where it can be overhead; a bright night can show it low in the sky from farther away.
• Giving up at Kp 3. “It should be noted that if you are in the right place under the aurora, you can see very nice auroral displays even with low geomagnetic activity (Kp = 3 or 4).”
• Trusting a clear forecast for a cloudy night. Kp says nothing about clouds: check the local weather too.

Plan the trip

Pack for it with the best cold-season destinations in mind, and in Alaska start with things to do in Fairbanks. Then check the best time to visit, the flight time and a packing list for the cold.