HealthSync: Air Quality

Most weather apps tell you the temperature. HealthSync tells you something more useful: when it is actually safe for you to be outside today.

Tell it what affects you — asthma, migraine, eczema, a heart condition, or general sensitivity to air quality. HealthSync checks the air where you are, hour by hour, and scores every hour against the things that matter for your condition specifically.

WHAT IT DOES • A simple 0–100 reading for right now, with a plain-English explanation of why • The best window to go out, whether that is a 30-minute walk or an afternoon of yard work • A warning when even the best window is still rough, instead of pretending it is fine • A reminder of what to bring — inhaler, sunscreen, a mask — but only when the weather actually calls for it

WHY HOUR BY HOUR Ground-level ozone is not emitted directly. Sunlight cooks exhaust fumes into it through the morning, it peaks in mid-afternoon, and it falls away after sunset. If ozone is your problem, a 7 AM walk and a 3 PM walk are genuinely different events. HealthSync is built around that difference.

HONEST BY DESIGN Every threshold comes from a published standard — EPA limits for fine particles, ozone and nitrogen dioxide, and the EPA UV Index scale. You can read all of them on the Sources screen, including the few we could not trace to a solid citation. We tell you which is which.

And when too much data is missing for an hour, HealthSync says “not enough data” instead of showing a confident zero. An app that reports perfect air because it has nothing to measure is worse than one that admits it does not know.

PRIVATE No account, no sign-up. Everything you enter stays on your phone. We ask only for approximate location, because the air quality grid is about a kilometre wide and a precise fix would tell us nothing more.

Weather and air quality data by Open-Meteo.

HealthSync is not medical advice and does not replace guidance from a doctor.

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