Blossom Frost Risk: Orchard Pollination Window

This 2D model derives fruit-tree bloom timing from first principles instead of a fixed calendar curve: a full year of simulated daily temperature is accumulated first as winter chill-hours (hours spent between 0°C and 7.2°C) until dormancy breaks, then as spring growing-degree-days above a 4.5°C base until the bloom threshold is reached. Every day inside the resulting bloom window is then checked against a frost-damage threshold and a bee-flight temperature threshold, so a day only counts as a successful pollination day when both hold — bees flying and no frost that morning. Winter-severity and spring-warming-rate sliders shift when the window opens; a day-to-day climate-variability slider adds realistic weather noise on top, and the built-in sweep tool replays dozens of seasons per variability level to show, directly from the simulated calendar, that greater variability reduces the number of successful pollination days even when the average climate is unchanged.