Can I see the northern lights tonight?

Check three things for your spot: the live OVATION cell, whether it is dark, and cloud. The aurora chance tool shows all three side by side, with the time each was read.

What Kp do I need to see the aurora?

It depends on your geomagnetic latitude. SWPC's rule puts the oval's edge at 66 degrees at Kp 0, 2 degrees lower per step. Duluth needs Kp 6 for the edge to sit overhead; Fairbanks needs Kp 1. See the Kp to latitude chart.

What time of night is best?

SWPC says usually within an hour or two of midnight, between 10 PM and 2 AM local time. The solar midnight tool shows when the sun is lowest where you are.

SWPC says the best seasons are around the spring and fall equinoxes. The far north also needs dark nights, so September to March there. See the best month guide.

Does the full moon ruin the aurora?

No, but SWPC says it diminishes the apparent brightness. Faint aurora suffers most. The moon planner counts moon-free dark hours per night.

How far south can the aurora be seen?

In a G5 storm SWPC lists sightings as low as Florida and southern Texas, typically 40 degrees geomagnetic. The storm levels hub lists each level.

How far away can I see the aurora?

SWPC says bright aurora can be seen from as much as 1000 km away with a clear view toward it. See how far away you can see it.

What does the percent on the NOAA aurora map mean?

SWPC derives it from modeled aurora intensity as an estimate of viewing probability, per 1 degree cell, 30 to 90 minutes ahead. It ignores your cloud and daylight. See how to read the forecast.

Why do Minneapolis and Duluth beat Seattle for aurora?

Geomagnetic latitude. Duluth reads 55.4 degrees and Minneapolis 53.5 on the dipole, against 53.0 for Seattle, which sits farther from the geomagnetic pole.

Can I see the northern lights in summer?

Not in the far north around midsummer, where the sun stays above -6 degrees all night. The lower 48 keep some darkness year round. See the midnight sun guide.

How much warning is there before a storm?

SWPC says CMEs typically take several days to reach Earth, and as little as 18 hours in the most intense cases. The OVATION map looks 30 to 90 minutes ahead.

Why does Glow show no live cloud forecast for Tromsø or Reykjavik?

Glow reads live cloud forecasts only from the US National Weather Service. Outside NWS coverage, town pages show NASA POWER's 2001 to 2020 monthly cloud average instead, clearly labelled as a long-term average.

Does Glow give an aurora score?

No. The OVATION cell, darkness and cloud come from different sources and fail in different ways, so Glow shows each with its timestamp instead of one blended number.

Which of the 10 Glow towns sits highest geomagnetically?

Reykjavik, at 68.8 degrees on the IGRF-14 dipole, just ahead of Yellowknife at 68.5. See the geomagnetic latitude ranking.

What are the G1 to G5 storm levels?

NOAA's geomagnetic storm scale. G1 Minor is Kp 5 and G5 Extreme is Kp 9. For each level SWPC lists where aurora has been seen and how often the level occurs per 11-year cycle. See the storm levels hub.

What is the best month to plan a trip?

Pick a month with long nights at your destination, preferably near an equinox, then center the trip on a new moon. The month hubs compare all 10 towns for each month, night by night.

Where does Glow get its numbers?

Live values come from NOAA SWPC and the NWS. Darkness and moon are computed with SunCalc; geomagnetic latitude from IGRF-14. Every quoted figure is in the sources ledger with its verified date.

Reference

Northern lights questions, answered

Answer

Short answers to the questions people ask most about the aurora, each tied to NOAA SWPC wording or a figure Glow computes, with a link to the guide or tool that goes deeper.

questions

Questions

Can I see the northern lights tonight?: Check three things for your spot: the live OVATION cell, whether it is dark, and cloud. The aurora chance tool shows all three side by side, with the time each was read.
What Kp do I need to see the aurora?: It depends on your geomagnetic latitude. SWPC's rule puts the oval's edge at 66 degrees at Kp 0, 2 degrees lower per step. Duluth needs Kp 6 for the edge to sit overhead; Fairbanks needs Kp 1. See the Kp to latitude chart.
What time of night is best?: SWPC says usually within an hour or two of midnight, between 10 PM and 2 AM local time. The solar midnight tool shows when the sun is lowest where you are.
What month is best?: SWPC says the best seasons are around the spring and fall equinoxes. The far north also needs dark nights, so September to March there. See the best month guide.
Does the full moon ruin the aurora?: No, but SWPC says it diminishes the apparent brightness. Faint aurora suffers most. The moon planner counts moon-free dark hours per night.
How far south can the aurora be seen?: In a G5 storm SWPC lists sightings as low as Florida and southern Texas, typically 40 degrees geomagnetic. The storm levels hub lists each level.
How far away can I see the aurora?: SWPC says bright aurora can be seen from as much as 1000 km away with a clear view toward it. See how far away you can see it.
What does the percent on the NOAA aurora map mean?: SWPC derives it from modeled aurora intensity as an estimate of viewing probability, per 1 degree cell, 30 to 90 minutes ahead. It ignores your cloud and daylight. See how to read the forecast.
Why do Minneapolis and Duluth beat Seattle for aurora?: Geomagnetic latitude. Duluth reads 55.4 degrees and Minneapolis 53.5 on the dipole, against 53.0 for Seattle, which sits farther from the geomagnetic pole.
Can I see the northern lights in summer?: Not in the far north around midsummer, where the sun stays above -6 degrees all night. The lower 48 keep some darkness year round. See the midnight sun guide.
How much warning is there before a storm?: SWPC says CMEs typically take several days to reach Earth, and as little as 18 hours in the most intense cases. The OVATION map looks 30 to 90 minutes ahead.
Why does Glow show no live cloud forecast for Tromsø or Reykjavik?: Glow reads live cloud forecasts only from the US National Weather Service. Outside NWS coverage, town pages show NASA POWER's 2001 to 2020 monthly cloud average instead, clearly labelled as a long-term average.
Does Glow give an aurora score?: No. The OVATION cell, darkness and cloud come from different sources and fail in different ways, so Glow shows each with its timestamp instead of one blended number.
Which of the 10 Glow towns sits highest geomagnetically?: Reykjavik, at 68.8 degrees on the IGRF-14 dipole, just ahead of Yellowknife at 68.5. See the geomagnetic latitude ranking.
What are the G1 to G5 storm levels?: NOAA's geomagnetic storm scale. G1 Minor is Kp 5 and G5 Extreme is Kp 9. For each level SWPC lists where aurora has been seen and how often the level occurs per 11-year cycle. See the storm levels hub.
What is the best month to plan a trip?: Pick a month with long nights at your destination, preferably near an equinox, then center the trip on a new moon. The month hubs compare all 10 towns for each month, night by night.
Where does Glow get its numbers?: Live values come from NOAA SWPC and the NWS. Darkness and moon are computed with SunCalc; geomagnetic latitude from IGRF-14. Every quoted figure is in the sources ledger with its verified date.

Quick answers by town

The Kp question depends on where you stand. This table applies SWPC's oval-edge rule and the NOAA storm scale to each of the 10 Glow towns.

Kp at which the SWPC oval edge reaches each Glow place
Place	Latitude	Dipole latitude	Edge overhead at	Kp 0 edge	Storm needed
Reykjavik	64.1°	68.8°	Kp 0	311 km south	No storm (Kp 0)
Yellowknife	62.5°	68.5°	Kp 0	280 km south	No storm (Kp 0)
Tromsø	69.6°	67.5°	Kp 0	166 km south	No storm (Kp 0)
Fairbanks	64.8°	65.7°	Kp 1	38 km north	No storm (Kp 1)
Anchorage	61.2°	61.9°	Kp 3	453 km north	No storm (Kp 3)
Duluth	46.8°	55.4°	Kp 6	1,183 km north	G1 or less
Minneapolis	45.0°	53.5°	Kp 7	1,391 km north	G3
Seattle	47.6°	53.0°	Kp 7	1,442 km north	G3
Portland, Maine	43.7°	52.9°	Kp 7	1,461 km north	G3
Buffalo	42.9°	52.0°	Kp 7	1,553 km north	G3

Kp 0 edge: distance along the geomagnetic meridian from the place to 66 degrees, at 111.2 km per degree. Storm needed: none at 60 degrees or more (SWPC's 60 to 75 degree band), G1 or less from 55 to 60, else the first NOAA storm level whose typical latitude reaches the place.

Sources and verification

NOAA SWPC, Tips on viewing the aurorahttps://www.spaceweather.gov/content/tips-viewing-aurora
NOAA SWPC, Aurora 30-minute forecasthttps://www.spaceweather.gov/products/aurora-30-minute-forecast
NOAA SWPC, Geomagnetic stormshttps://www.swpc.noaa.gov/phenomena/geomagnetic-storms

Quoted figures last checked against their sources on 2026-09-30; next review 2026-12-31. Computed figures come from SunCalc and the IGRF-14 dipole as described in the methodology. Every quote is listed in the sources ledger.

Questions

Quick answers by town

Related pages

Sources and verification