Freyr Sunset vs Open Your Windows

Around 4.5 billion years ago, the Earth started orbiting the sun. Since then, there have been trillions of sunsets, but humans have only been around to see about 73 million of them. For each of those sunsets, there were people watching, awed by the colors, thinking deep thoughts. We made this app because we love that feeling so much. After testing our forecasts empirically for years, we finally feel we’re accurate enough to help you decide when a sunset will be worth watching. But regardless of what we say, you’ll never regret going out to see a sunset. When in doubt, check it out.

Fresh air, without the guesswork. Open Your Windows gives you one simple answer: is right now a good time to open the windows? Most days you want fresh air. But checking a weather app, an AQI app, and a pollen app to decide takes five minutes and three different recommendations. Too long if you'd like to check several times a day, and if it's important to you to get fresh air. This app looks at all of it — temperature, humidity, dewpoint, air quality, pollen, wind gusts, and rain forecasts — and gives you one clear recommendation with a plain-English reason. What you see — Open, Maybe, or Keep Closed. One answer, right now. — Plain-language reason ("It's a comfortable 72° and AQI is 42 — in the good range.") — Short-term outlook so you know how long conditions will hold. — Home screen widget in two sizes for glance-and-go checks. — Parameter detail when you want to see the why. — Pollen sensitivity toggle for allergy-prone households. How it decides It's not AI. It's a deterministic rule engine with thresholds tuned for real household comfort. Hard vetoes for unsafe air. Soft modifiers for things that affect how pleasant it'll feel. Short-term forecast awareness so you're not told to open right before a storm. Hysteresis so the answer doesn't flip every two minutes on borderline days. If conditions are genuinely borderline, it says Maybe and tells you why. If something upstream breaks or good weather data are not available, it says so instead of guessing. Trust comes from predictability. Privacy, seriously — No account. No login. No tracking. — Your location is used to fetch weather for your spot, then discarded. Never stored on our servers. — Analytics are anonymous. No device IDs. No IP addresses. No location. — API keys for weather, AQI, and pollen providers stay on our backend. Your phone never talks to them directly. Who it's for Anyone who loves fresh air and doesn't love checking three apps to decide. Parents of kids with allergies. People with asthma. Anyone who's opened the windows on a day the pollen count was secretly brutal and paid for it the next morning. Not a medical device. This is a household comfort tool, not allergy advice. If you have serious respiratory conditions, talk to your doctor — but let this app take "is today a good day?" off your list. Built in the spring in the Midwest by one person with allergies and asthma who wanted an app that just gives him the answer.