Everything on the home screen answers one question: what is it going to do, and what should I do about it. Here is what each part means, from the top down.
The painted garden is now. The sky, the light and what the dad in it is wearing all follow the forecast for this hour. Underneath it, the graph is the whole day, six in the morning to ten at night.
Drag the graph, or drag the picture, and the big temperature, the sky, the wind and the painted scene all follow the hour you land on. The handle names that hour. The dotted line stays where the actual time is, so you can see how far ahead you have wandered. Nothing you do to it changes the forecast, so have a poke about.
The percentage and the marks answer two different questions. The percentage is the chance of any rain at all. The marks are how much of it, if it comes.
Three marks on a single hour is heavier going than three marks across a whole day, because the same amount of rain spread over a day is an ordinary wet Tuesday. We never print millimetres, because nobody thinks in them. The same three marks appear on the graph, in the hours, and on every day of the week.
The arrow points the way the wind is going, and its colour says whether that matters to you.
A gust can push an hour up a band on its own, because it is the gust that takes the washing stand over, not the average. Where that happens the hourly prints the gust beside the average, so the number behind the colour is always there to find.
Every day says what it is, worked out from that day's own hours rather than a blanket rule.
Green is a day worth going outside for. "Rain from ten" means the rain arrives at ten and stays, "Dry from eleven" means it clears then, and "Showers about" means it is scattered and no hour is safe. Tap any day to open it hour by hour, and to see what each of the five forecasts makes of it.
When rain is on the way, the panel says when it starts, and whether it turns heavy or eases off: "Rain in ~19 min", then "Heavy by 10:20, easing after 11". The bars are the next sixty minutes, minute by minute, coloured on the same shower, wet and soaking scale as everything else.
On a dry day it collapses to one green line, "No rain for 6 hours", because there is nothing to draw. Either way, the count on the right says how many of the five forecasts agree, and tapping it names them.
Still wondering about something? The FAQ goes further, and every forecast we make is scored in public on the accuracy page, including the ones we get wrong.