Stable release. 3.7 graduates to stable. Drop-in upgrade from 3.6.x or any 3.7 pre-release — no breaking changes, no config changes required.
Headline features
Smooth motion — opt-in motion_compensation: true. During each frame transition, rain slides along its actual direction of travel instead of crossfading in place, so the loop reads as one continuously drifting rain field. Pyramidal Lucas-Kanade optical flow, runs in a Web Worker, works across all three radar sources. Built on top of @genericJE's #156. Pairs naturally with smooth_animation.
type: 'custom:weather-radar-card'
smooth_animation: true
motion_compensation: trueAdjustable playback speed — toolbar button cycles ¼× / ½× / 1× / 2× / 4×, with a YAML default. Optional per-user persistence (viewer_layer_control: true) so each viewer's chosen speed follows them across browsers and devices. Contributed by @genericJE.
Also in 3.7
- NOAA radar rebuilt on NCEP's opengeo GeoServer (the radar.weather.gov backend) — newest frame ~2 minutes behind real time instead of 15–25, every frame a distinct scan, and a new Frame interval dropdown (2 / 5 / 10 min). The newest-frame label now reads "Latest" rather than "Now" since radar always lags real time.
- Canvas rendering for lightning and hazard overlays — strikes, alert polygons, and fire perimeters paint to canvas instead of per-item DOM. Identical visuals and clickability; soak-validated during live storms at 10,000 simultaneous lightning strikes with the page fully responsive.
- Stability wave — full-project code-review remediation: refresh/state races (no more duplicate-frame accumulation on long-running dashboards), DWD coverage clipping + single shared boundary mask, exponential backoff on alert/wildfire fetch failures, bounded caches, antimeridian fixes for Alaska.
- 11-language translation parity for all the new editor strings.
Notes for upgraders
Legacy frame_count is still honoured but now warns when combined with past_minutes / frame_stride_minutes (it's ignored in that case — use the time fields). It will be removed in the next major.
Full 3.7 changelog: v3.6.5...v3.7.0