We compare complete daylight windows between 6 AM and 8 PM and leave 30 minutes before sunset. Past hours, missing data, thunderstorms, and hours exceeding your rain or gust limits are excluded. Penalties favor lower rain, sustained wind below 10 mph, gusts below 20 mph, and apparent temperatures of 42–75°F. Riding adds a wind penalty; running adds a heat penalty above 75°F. Equal scores favor the earlier start. These are adjustable planning heuristics, not validated safety thresholds. A selected route point does not represent conditions across the whole route.