Guide · Planning a night or a trip
When is it too light for the northern lights?
Answer
Why summer is off the table in the far north
"Of course, to observe the aurora, the skies must be clear and free of clouds. It must also be dark so during the summer months at auroral latitudes, the midnight sun prevents auroral observations."
The aurora does not stop in summer. The oval keeps circling the magnetic pole all year. What stops is the dark. At high latitude the summer sun either never sets or sets so shallowly that twilight fills the night. SWPC's tips page adds a blunt line for travelers: combining a summer vacation to the Arctic with aurora watching usually does not work.
Midnight sun, where the sun never sets, is only part of the problem. White nights, where the sun sets but stays within 6 degrees of the horizon, are just as bright for aurora purposes. Glow counts both as no civil darkness.
No-darkness dates and the dark season
The table scans every day of 2026 at 15 minute steps. The first columns give the longest run of nights where the sun never reaches -6 degrees. The last columns give Glow's dark season: days with at least 4 hours of civil night between 18:00 and 06:00 local time.
| Place | No civil night | Nights | Dark season | Days |
|---|---|---|---|---|
| Fairbanks | May 13 to July 28 | 77 | August 9 to May 1 | 266 |
| Anchorage | June 2 to July 8 | 37 | July 28 to May 13 | 290 |
| Seattle | Every night has some | 0 | All year | 365 |
| Minneapolis | Every night has some | 0 | All year | 365 |
| Duluth | Every night has some | 0 | All year | 365 |
| Portland, Maine | Every night has some | 0 | All year | 365 |
| Buffalo | Every night has some | 0 | All year | 365 |
| Reykjavik | May 17 to July 25 | 70 | August 8 to May 3 | 269 |
| Tromsø | April 27 to August 14 | 110 | August 23 to April 18 | 239 |
| Yellowknife | May 25 to July 16 | 53 | August 2 to May 8 | 280 |
Tromsø has the longest no-darkness run of the 10 places, because it sits farthest north at 69.6 degrees. Fairbanks and Reykjavik follow. Anchorage and Yellowknife, a little farther south, lose civil night for a shorter run around the June solstice.
The five lower 48 towns never lose civil night. Even in June, Minneapolis keeps 7.0 hours on the 15th and Seattle 6.5. Their dark season, by Glow's 4 hour bar, runs all year. Whether summer aurora is seen there is a question of storm strength, not daylight.
Why Glow's season needs 4 evening hours
A night with 20 minutes of civil darkness is technically dark but useless for planning. Glow's dark season therefore asks for at least 4 hours of civil night between 18:00 and 06:00 local time. That bar matches the length of SWPC's 10 PM to 2 AM window. It is Glow's own definition, stated on every page that uses it, and not an official season.
The 18:00 to 06:00 frame keeps polar edge cases honest. In deep winter at Tromsø, civil night runs well past 06:00 and starts before 18:00. Only the evening hours count toward the season test, so the figure stays comparable across places.
Each place page draws the same daily scan as a full-year night ribbon. The dark band narrows through spring, disappears for the no-darkness weeks and widens again in late summer. The aurora season finder draws that ribbon for any coordinates, including towns Glow does not list, and marks the dates where the dark season opens and closes.
Planning around the light
- Check your dates in the aurora season finder, which draws a full-year ribbon for any coordinates.
- Near the edges of the dark season, use the dark hours calculator for the exact night.
- Compare two destinations with the comparison tool, which lists no-darkness dates side by side.
- Read the equinox guide for how fast nights change in March and September.
For Fairbanks, the month pages show the change: Fairbanks in August as the dark returns, and Fairbanks in April as it fades.
Questions
- Can you see the northern lights in summer?
- Not at high latitude around midsummer, where the sun stays above -6 degrees all night. SWPC says the midnight sun prevents auroral observations there. Lower latitude towns keep some darkness every night.
- When does aurora season start in Fairbanks?
- By Glow's bar of 4 hours of evening civil night, Fairbanks' season opens in early August. The table on this page gives the exact dates for 2026.
- Is there midnight sun in Reykjavik?
- The sun does set at Reykjavik in June, but it stays within 6 degrees of the horizon, so there is no civil darkness for about ten weeks. The table gives the exact run.
- What is the dark season on Glow?
- Days with at least 4 hours of civil night, sun at or below -6 degrees, between 18:00 and 06:00 local time. It is Glow's own definition.
- Does Minneapolis have nights with no darkness?
- No. Minneapolis keeps 7.0 hours of civil night even on June 15.
Sources and verification
- NOAA SWPC, Aurorahttps://www.swpc.noaa.gov/phenomena/aurora
- NOAA SWPC, Tips on viewing the aurorahttps://www.spaceweather.gov/content/tips-viewing-aurora
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.