When flowers bloomacross the country

Two kinds of map

The badge above the map always names the one on screen.

Modeled is the strictest kind. The date in every cell is worked out from thirty years of daily temperature records (1991–2020) and was checked against an independent national reference before it was allowed on this map. These maps print a date, and In bloom on them is a real count: the share of those thirty years in which a place was in flower on the chosen day.

Typical window is the honest kind for flowers nobody tracks station by station. It shows the stretch of the year this flower usually opens in each place, built from real dated bloom records and each cell’s own thirty-year temperature history. The colour follows the middle of that window; the true answer is the whole window, and the tooltip prints it for any point you touch. In bloom works here too, without percentages; the tone simply rises towards the middle of the window.

The colour is the calendar

The colour of a day is the same on every flower. The scale is the calendar itself, the whole year of it, so April on the lilac is the April on the magnolia. The legend shows the full year and lifts the veil over the months the flower on screen actually uses.

What the hatching says

Hatched ground is the honest part, and its language is the same on every flower. Clay-coloured lines are the warm side of the plant’s range: winters too mild, or the wrong summers. Slate-coloured lines are the cold side: winters or frost the plant does not get past. Lines over colour mean the flower grows here at its limit and a date still stands; lines over bare paper mean the map refuses to print a date at all.

Ink dots are about the data, not the plant: high ground keeps its colour and its date under dots because the reading up there has less to lean on. Flat grey means no records and no claim either way. The legend lists all six signs in the same order on every flower, and dims the ones the current map does not use. Tap or hover anywhere hatched: the standard phrase comes first, with whatever is particular to that plant under it in one line.