Every shade answer on this site is computed, not written. This page says exactly what goes into one, and, just as importantly, what we don't claim to know.
We calculate the sun's true position (via the suncalc ephemeris) for the exact date, start time, and venue timezone you pick: azimuth and altitude to the minute, at the venue's own coordinates. A 1:10 PM April game and a 1:10 PM August game at the same park get genuinely different suns, not one generic "summer afternoon" diagram.
Shade at a seat depends on which way the venue faces, so every venue with a full seat-shade page carries a verified compass orientation. MLB ballparks are cross-checked against MLB's own Stats API azimuth data for each park; other venues are measured from satellite imagery and USGS 3DEP lidar surface models, with a confidence gate that requires independent measurements to agree. When a venue doesn't pass that gate, we don't guess. It gets an honest "quick check" page (sun position, sunset vs. showtime, heat) instead of a possibly-wrong seating map.
For satellite-shadow views, roof outlines and heights come from real measurement wherever possible: 477 of the 575 venues and landmarks we've baked use USGS 3DEP aerial lidar, actual scanned roof surfaces, with a freshness gate that rejects scans flown before a venue was built or rebuilt. Sites without usable lidar fall back to Overture/OpenStreetMap building data. Tree canopy comes from the lidar canopy-height model, with Meta/WRI 1-meter global canopy data as the fallback. Each venue's data source is credited right in the app ("USGS 3DEP lidar" vs. "Overture"), so you can see which tier you're looking at.
We audited the shadow model against real satellite photographs, rendering our predicted shadows for the moment a satellite image was captured and comparing. Across the roughly 240 venues where a clean comparison was possible, the model agreed with the imagery about 90% of the time, and the misses fed fixes. The per-section seating model is additionally pinned by a fan-wisdom test suite (e.g. Fenway's covered grandstand shades from first pitch while the bleachers bake) that runs before every deploy.
Shade isn't the whole verdict. An hour-by-hour forecast (NWS for US locations, Open-Meteo otherwise) supplies temperature, UV, and cloud cover for your exact hour, and that's fused into the recommendation. A cloudy 68°F afternoon reads differently than a cloudless 96°F one.
All venue shade guides · Landmark heat & sun guides · Interactive app