GUIDES / OBSERVING
Space station sightings in winter
By Jeroen Wouda · 2 November 2026 · Observing
The station is equally bright in January and in July. What changes is when you can see it, and winter wins on almost every count: the sky is dark by early evening, the station is still in sunlight, and the pass happens at a time when you are awake and indoors with a coat within reach.
The geometry behind an evening sighting
For the station to be visible you need it lit while your sky is dark. It orbits at about 400 kilometres, high enough that it stays in sunlight for a while after the ground beneath it has passed into shadow. The Earth's shadow is a cone, and at that altitude the cone is narrower than the planet: the station can be in sunlight while you are in darkness, and that overlap is your window.
In winter the Sun sets early. By the time the sky is properly dark, evening is still young and the station is often catching sunlight somewhere over the Atlantic or the Continent. In summer the reverse applies: the Sun sets late, the sky stays bright for a long time, and by the time it is dark the station has slipped into shadow.
Convenient hours
This is the practical heart of it. A winter evening pass might fall between six and nine, when you are home, warm and able to step outside for five minutes. A midsummer pass of comparable quality may not happen until after eleven at night, or may not happen at all during darkness.
At higher latitudes the effect is stronger. Around the solstice the sky never becomes fully dark, only dimming to a deep twilight, and the faint passes are lost entirely. Winter gives the opposite: long, genuinely dark evenings with a station that is often sunlit during them.
The shadow edge
One of the small pleasures of winter observing is watching the station fade. On many evening passes it does not set behind the horizon at all. It enters the Earth's shadow part-way across the sky and dims abruptly, sometimes over a few seconds, and is gone. People who do not expect this assume they lost it, or that something went wrong.
If you know it is coming it is worth watching. The cut-off is sharp, and the timing can be read off the pass data.
Cold, clear air
Winter air is often drier and less hazy than summer air, which usually means better transparency: the sky looks cleaner and fainter stars are easier. The trade is comfort. Steady air is not guaranteed in winter, and a turbulent cold night can blur everything, but for spotting a bright moving point that hardly matters.
What does matter is being dressed for it. A pass lasts a few minutes, but you will want to be outside a little before it starts, and you will not enjoy it if you are cold. Gloves make phone use awkward; check the time before you go out rather than standing there scrolling.
Practical notes for a winter evening
- Check the pass the day before, and again on the day; element sets age.
- Keep the phone in an inside pocket, since cold drains batteries quickly.
- Let your eyes adjust before the pass rather than during it.
- Stand out of the wind if you can; a wall or a doorway helps more than a thicker coat.
- Use familiar winter constellations as reference points. Orion and Sirius are unmistakable and make it easy to judge which way to face.
What about summer
Summer is not useless. Late evening passes still occur, and the station can look striking against a deep blue sky rather than a black one. But the windows are fewer, later and shorter, and the long twilight does much of the work that streetlights do in a city. If you have a choice of seasons for a first attempt, winter is the easier teacher.
A note on the cold months
Nothing about the station changes in winter. Its orbit, its brightness and the geometry that produces a good pass are the same all year. What winter changes is your access to the dark part of the day, and that is the whole of the advantage: more chances, at better hours, for longer.
Where to go next
- ISS passes for the current week's evening times.
- What the ISS actually looks like from the ground explains the brightness you are watching for.
- Light pollution and seeing satellites for what city glow does and does not hide.
More guides
- What the ISS actually looks like from the ground — Why the space station is a point of light rather than a shape, and why its brightness changes from one pass to the next.
- Light pollution and seeing satellites — City glow hides faint stars but not a bright pass. What light pollution actually takes away, and how to work around it.
- Spotting the ISS from a balcony or a small garden — No telescope, no dark sky and no big garden needed. A workable method for seeing passes from a small, obstructed space.