That sounds simple, which is exactly the point. You choose a city or use your current location, pick an available forecast day, and tap the sun. Behind that one tap, Where Sun builds a small map of possible escapes: towns, beaches, parks, viewpoints, nature spots and outdoor places close enough to become a real plan.
First we find real nearby places
A sunny result is not helpful if it is only a weather station or a random coordinate. The app needs places people can actually go. So the first step is place discovery: nearby towns for reliable anchors, plus outdoor places like parks, beaches, nature reserves and viewpoints for the more interesting answers.
That mix matters. If the app only showed towns, it would feel like a normal weather list. If it only showed parks, it would miss the obvious sunny town twenty minutes away. Where Sun blends both because weekend decisions are messy in a human way.
Then we check the weather around them
Once we have candidate places, we check the forecast for the selected day. The app looks for signals that match what people mean by "sunny": cloud cover, rain risk, temperature, daylight usefulness and the kind of weather that makes a walk, picnic or beach plan feel worth it.
Distance still matters. A perfect sky three hours away is not always a better answer than a good-enough sky thirty minutes away. Where Sun ranks places with that tradeoff in mind: better weather is the main goal, but a result still needs to feel reachable.
Why it feels fast
Place discovery and weather checks run in parallel wherever possible. The app also avoids making the user think about weather models, coordinates or data sources. That complexity stays behind the sun button. The result should feel like a short, useful answer: go here, this place looks better, and it is this far away.
Why it stays private
Where Sun does not need an account to answer the question. Saved places stay on your phone. Location is optional. You can type a city manually and get the same kind of answer without sharing your current position.
That privacy constraint is part of the product design. The app should help you make a plan, not become another service you have to manage.
The goal
Where Sun is not trying to replace a full weather app. It is a small decision engine for one moment: you want to go outside, the weather near you looks uncertain, and you need to know whether the sun is hiding somewhere close enough to chase.