For Accident Reconstruction & Crash Investigation

The sun, moon, and weather at the exact time of the crash

Reconstruct the environmental baseline for any collision: sun altitude and azimuth, moon phase and position, and multi-source weather, cited to the exact place and minute in local time.

5 free reports a month. No credit card.

Every collision reconstruction needs the conditions the drivers actually faced. Conditions.Site pulls the sun position, moon phase, and historical weather for any past date and time, down to the minute, at the exact scene, in the location's own local time. It factors in local terrain and nearby buildings when it determines whether the sun or moon was above the visible horizon, and it cites every value back to the public source it came from.

The problem

Where the usual sources come up short when you need to establish what the conditions were.

Was the sun in the driver's eyes?

You need the sun's altitude and azimuth at the moment of impact, then compared against the direction of travel. Guessing from a generic sunset table ignores the driver's heading and the low-angle glare that matters most.

Generic sunset times ignore the terrain

An almanac says the sun set at 5:44pm. But a ridgeline, a hill, or a building can block it minutes earlier. A flat-horizon time can put the sun above the horizon when it was already gone from the scene.

How much natural light was on an unlit road?

For a nighttime pedestrian or cyclist collision, the moon's contribution matters. You need whether the moon was up, its phase and illuminated fraction, and its position, not a vague full or new label.

Weather that disagrees across sources

One station says clear, another says rain. Without cross-checking independent public records, a single number is easy to challenge. You need the conditions reconciled and every value traced to its origin, so the record is well-documented and fully traceable.

How it's used

Low-sun glare on an eastbound morning commute

Pull the sun's altitude and azimuth at the crash time, then read it against the driver's direction of travel to assess whether a low sun sat in the field of view at that intersection.

Nighttime pedestrian collision on an unlit road

Establish whether the moon was above the horizon, its phase and illuminated fraction, and its azimuth, to describe the moonlight available at the scene that night.

Wet or foggy roadway reconstruction

Reconcile temperature, precipitation, humidity, visibility, and cloud cover across independent public sources to build a well-sourced, fully cited picture of the roadway environment at the minute of the crash.

Terrain-aware dusk timing near a hillside

Determine whether the sun had already dropped behind local terrain or buildings at the scene, so the true onset of low light isn't overstated by a flat-horizon sunset time.

What you get

Every value is cross-checked across independent public sources and cited back to its origin.

Sun altitude, azimuth, and terrain-aware horizon

Altitude and azimuth at the minute you specify, plus sunrise, sunset, solar noon, and twilight times. Local terrain and nearby buildings are factored into whether the sun was actually above the visible horizon at the site, so you can read glare against the direction of travel.

Moon position, phase, and illuminated fraction

Moon altitude and azimuth, moonrise and moonset, phase, and illuminated fraction, also terrain- and building-aware. The baseline for how much natural light was available on an unlit road at the time of a nighttime collision.

Weather reconciled across independent sources

Temperature, wind speed, direction and gusts, precipitation, cloud cover, humidity, visibility, and pressure, drawn from multiple independent public sources such as ERA5 reanalysis, NOAA/NWS station records, and personal weather stations, cross-checked against each other with every value cited.

A clean, paginated cited PDF report

A one-page visual summary, a per-source comparison table, an hourly table, and per-station detail. Every number is traceable to the public source it came from, so the environmental baseline is documented and easy to review.

How it works

  1. Enter the scene and the moment

    Search the address or intersection, or drop in GPS coordinates, then set the date and time to the minute in the location's own local time.

  2. We assemble and cross-check the record

    Conditions.Site computes the sun and moon position with terrain and buildings in view, and reconciles the weather across multiple independent public sources, citing every value.

  3. Review and export the cited report

    Read the visual summary, then open the per-source, hourly, and per-station tables. Export a clean, paginated PDF and save it to your account history.

Frequently asked questions

What was the sun's azimuth and altitude at the intersection at the time of the crash?
Enter the intersection (by address or GPS) and the date and time to the minute, and the report gives the sun's altitude and azimuth at that moment in local time, plus sunrise, sunset, solar noon, and twilight times. Read the azimuth against the driver's direction of travel to assess low-sun glare.
Was the sun low enough to be in a driver's eyes at a specific time and location?
The report gives the sun's altitude (how high above the horizon) and azimuth (compass bearing) at the exact minute. A low altitude combined with an azimuth near the direction of travel indicates potential glare. Conditions.Site provides the modeled sun position; you apply it to the driver's heading and sight lines.
How much moonlight was there the night of a pedestrian accident?
The report shows whether the moon was above the horizon at that minute, its altitude and azimuth, its phase, and its illuminated fraction, with local terrain and buildings factored into visibility. That is the natural-light baseline for the scene. It does not report a brightness or illuminance figure in footcandles.
Was the moon above the horizon at the scene at the time of the collision?
Yes, the report gives moon altitude and azimuth for the exact place and minute, along with moonrise and moonset, and accounts for local terrain and nearby buildings in determining whether it was above the visible horizon at the site.
Does it account for terrain when giving sunset time at the scene?
Yes. Beyond the flat-horizon sunset time, Conditions.Site factors in local terrain and nearby buildings when determining whether the sun was actually above the visible horizon at the location, so the onset of low light isn't overstated for a scene near a hill or ridgeline.
Can I get historical cloud cover and visibility for a nighttime reconstruction?
Yes. The weather report includes cloud cover, visibility, precipitation, humidity, wind, and more for any past date and time, reconciled across multiple independent public sources with every value cited. Reports are modeled estimates assembled from cited public data for informational use, not a guarantee of actual conditions.

Document the conditions behind the collision

Generate a clear, cited report of the sun, moon, and weather at the exact place and minute of a crash, in local time. Start with 5 free reports a month, no credit card, or go unlimited for $19.99 a year.

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Related uses

Conditions.Site reports are modeled estimates assembled from cited public data sources for informational use; they are not a guarantee of actual conditions.