ToolComputedCited
What time is solar midnight here?
Answer
Worked example
Reykjavik sits at 21.90W but keeps Atlantic/Reykjavik time, which is UTC+0 all year. The sun reaches its lowest point at 01:16 clock time on the night of October 1, 2026, 1 h 16 min after 00:00. A clock set to the town's own longitude would be close to UTC-1:28, and the difference shows up as a late solar midnight.
The table ranks all 10 Glow places by the same offset for tonight.
| Place | Clock time | Offset | |
|---|---|---|---|
| AnchorageAmerica/Anchorage | 01:48 | +108 min | -32.0° |
| FairbanksAmerica/Anchorage | 01:40 | +100 min | -28.3° |
| YellowknifeAmerica/Yellowknife | 01:26 | +86 min | -30.7° |
| ReykjavikAtlantic/Reykjavik | 01:16 | +76 min | -28.9° |
| BuffaloAmerica/New_York | 01:04 | +64 min | -50.2° |
| MinneapolisAmerica/Chicago | 01:02 | +62 min | -48.1° |
| SeattleAmerica/Los_Angeles | 00:58 | +58 min | -45.5° |
| DuluthAmerica/Chicago | 00:57 | +57 min | -46.3° |
| TromsøEurope/Oslo | 00:33 | +33 min | -23.3° |
| PortlandAmerica/New_York | 00:30 | +30 min | -49.4° |
Solar midnight versus clock midnight
Solar midnight is the moment the sun reaches its lowest point below your horizon, halfway between one solar noon and the next. It depends on your longitude. Clock midnight depends on your time zone, which is set by law for a whole region and shifted an hour by daylight saving time.
Inside a time zone, places at the zone's western edge see solar midnight later on the clock than places at its eastern edge. Summer time adds an hour to the clock on top of that. The result can move solar midnight well past 01:00.
Glow reads the nadir time from SunCalc for the night you pick, formats it in the time zone you pick, and reports the gap from 00:00 in minutes.
Where the SWPC window sits
SWPC's viewing tips put the best aurora within an hour or two of midnight and give the window in local time: 10 PM to 2 AM. The tool lines that window up against solar midnight so you can see how the two relate at your place.
When solar midnight falls after 01:00, the clock window starts earlier in the sun's night than the numbers suggest. Glow does not move the window for you, because SWPC gives it in local time. The offset is shown so you can decide how late to stay out.
The sun's altitude at solar midnight
The altitude row tells you how dark the darkest moment gets. At -18 degrees or lower the sky reaches astronomical night. At -6 degrees or lower it is civil night. Above -6 degrees there is no civil night at all, and in high-latitude summer the figure can be positive, meaning the sun never sets.
SunCalc's altitude includes standard atmospheric refraction. Terrain, buildings and weather are not part of the calculation.
Questions
- What time is solar midnight tonight?
- It depends on your longitude, time zone and date. The tool computes it with SunCalc and formats it in the IANA time zone you choose.
- Why is solar midnight after 1 AM where I live?
- Your location sits west of your time zone's reference meridian, daylight saving time is in effect, or both. Each adds to the clock time of the sun's lowest point.
- Should I shift the 10 PM to 2 AM window to match solar midnight?
- SWPC gives the window in local time. Glow shows it as published and prints the offset so you can make your own call.
- Is solar midnight the darkest time of night?
- It is when the sun is lowest, so the sky is darkest then if nothing else changes. The moon can rise or set at any hour and change that.
- Why does the offset change between summer and winter?
- Daylight saving time moves the clock by an hour, and the equation of time shifts solar midnight by several minutes across the year, which the table recomputes for each date.