Nature Says When

Nature Says When is a free outdoor decision engine that helps people decide when to go outside. Choose an activity, duration, place, and timing constraints, and it evaluates the full activity window using weather forecasts, precipitation, wind, heat and cold, air quality, wildfire-smoke context, UV and daylight, and relevant official alerts. It recommends the earliest workable window the available data supports, explains the important tradeoffs, and keeps uncertainty and source limitations visible. No account is required.