ISS and Satellite Pass Predictions for Any Location

When will the ISS, Tiangong, Hubble or any tracked satellite pass over a place, where in the sky should you look, and will the clouds let you see it?

Send one location or a thousand. For each, you get every pass in the window with rise, peak and set times, compass directions, peak elevation and visibility, plus the forecast cloud cover, visibility and fog at the moment it peaks. Or ask for a live list of everything overhead right now. You pay per location, not per pass.

Run it with the default input: the next 24 hours of ISS passes over London.

Who uses it

• Agent and chatbot builders answer "is the ISS going over tonight?" with one tool call.
• App and smart-home developers send an alert, or flash a light, ten minutes before a visible pass at each user's own location.
• Teachers and astronomy clubs plan an evening's viewing: what crosses the sky after dusk, where to look and how high it climbs.

Input

Field	What it does
mode	passes (default) or overhead (what is above the horizon now)
locations	A list of {"lat", "lon", "alt_m", "label"}, up to 1,000 per run
filter	Empty means the ISS. Or brightest, norad:25544,48274, or a group such as group:stations or group:oneweb
hours	How far ahead to look, 1 to 72. Default 24
minElevation	Ignore passes lower than this, in degrees. Default 10
visibleOnly	true returns only passes where the satellite is lit against a dark sky
includeWeather	Sky forecast for each pass. Default true; reaches about 16 days ahead
start	Start the window, or set the moment for overhead, as ISO 8601
radiusDeg	For overhead: 90 is the whole sky, 30 is near straight up

Output

Each pass carries name, norad_id, rise_time, peak_time, set_time (UTC, to the second), rise_compass, peak_compass, set_compass, peak_elevation, duration_s, visible, visible_from, visible_to, magnitude (ISS, Tiangong and Hubble) and data_as_of.

The sky at the peak comes in sky: verdict (clear, partly_cloudy, poor or fog), a one-line reason, cloud cover for the low, mid and high layers, visibility_m, fog and precipitation_probability_pct. naked_eye_viewable puts it together: the satellite is lit, your sky is dark and the clouds should allow it. Past the forecast range, sky is null and sky_note says why.

A real visible pass of Tiangong over London, trimmed. Bright enough, but the forecast says stay in:

{
  "location_label": "London",
  "name": "CSS (TIANHE-1)",
  "norad_id": 48274,
  "rise_time": "2026-10-09T04:18:58.000Z",
  "rise_compass": "SW",
  "peak_time": "2026-10-09T04:20:41.000Z",
  "peak_compass": "S",
  "peak_elevation": 13.9,
  "set_time": "2026-10-09T04:22:26.000Z",
  "set_compass": "SSE",
  "duration_s": 208,
  "visible": true,
  "magnitude": 0.6,
  "naked_eye_viewable": false,
  "sky": {
    "verdict": "poor",
    "reason": "Mostly cloudy (low 97%, mid 1%, high 66%)",
    "cloud_cover_low_pct": 97,
    "cloud_cover_mid_pct": 1,
    "cloud_cover_high_pct": 66,
    "visibility_m": 19143,
    "fog": false,
    "precipitation_probability_pct": 40
  }
}

overhead rows give each object's compass direction, elevation, range and height, highest first.

Pricing

Pay per location queried. See the Pricing tab for current rates; the number of locations sets the cost. A location with no passes charges nothing.

FAQ

How current is the orbital data? Predictions use the latest orbital elements we hold, and every row carries their age in data_age_hours.

Can I do Starlink? Yes, in overhead mode, or by listing catalogue numbers in passes mode (up to 200 per location).

What does "visible" mean? The satellite is in sunlight while your sky is dark enough to see it. naked_eye_viewable adds the weather: it is true only when the forecast for that minute is clear or partly cloudy.

How far ahead is the sky forecast? About 16 days. Passes further out, or in the past, carry sky: null with a sky_note. Set includeWeather to false to leave it out.

Every row carries an attribution field; keep it if you republish. Runs record anonymous usage counts only, never your inputs or results.