Stadium shade

Stadium Shade (Shadium for short) shows sun and shade at an outdoor stadium for a game time. Pick a stadium, the game date and the start time. Times are on the stadium's local clock, including daylight saving time. The sport sets a typical game length in hours, which you can change. Near me lists the stadiums closest to you; your browser's location is used only on this page and is not sent anywhere, saved, or added to the link.

The 3D model is Google's photorealistic 3D imagery of the stadium and the blocks around it. Photo shows the imagery in color, darkened where the computed sun shadows fall and dimmer as the sun gets low. The photos also keep the shadows from the day they were taken, so Clay draws the same model in plain gray: light gray surfaces are in direct sun and dark gray surfaces are in shade. The gold disc is the sun, the gold line is its path across the day with hour marks on the stadium's clock, and the green ring marks north, east, south and west. Google's 3D imagery doesn't cover every region in detail (most of South Asia and the Caribbean, for example); there the model shows only rough terrain, and a note over the view says so.

The slider runs from an hour before sunrise to an hour after sunset, in 5-minute steps. The gold band is the game and the mark is its start. Ticks and short labels in the band mark the quarters, halves, innings or sessions and the breaks (hatched); their times are typical averages, not a schedule. Sun view turns the camera toward the sun with the sun in the frame; Overhead looks straight down with north at the top.

A stadium with a fixed roof gets no direct sun on the field, so it has no 3D view. A retractable roof is shown the way it was when photographed; the sun reaches the field only when it is open. Places found through the Google Places search are not in the stadium list, so their roof type is unknown.

Sun positions come from the NOAA solar equations, within about 0.02° of NREL's solar position algorithm. Clouds and weather are not modeled.

Which stadium seats get sun and which get shade works through the same geometry by hand for baseball and football stands.