Heliograph vs Hygrometer

Heliograph is a focused, native space-weather app for Solar Cycle 25. It pulls current conditions and short-horizon forecasts directly from public government sources and shows them plainly — with an honest timestamp on every value. What "live" means here Heliograph shows real conditions and short-range forecasts — not millisecond telemetry. While the app is open it refreshes on each source's own cadence, and every reading carries an "as of" timestamp so you always know how fresh it is. The freshest inputs come from NOAA's SOLAR-1 spacecraft at L1: in-situ solar wind within about 5 minutes, CME imagery within about 30 minutes — that is the ceiling, and we never pretend to beat it. Typical refreshes: aurora oval ~5 min, solar wind ~60 s, Kp ~15 min, NOAA G/S/R scales ~5–10 min, X-ray flares ~60 s, solar cycle daily. When solar-wind data is unavailable, the aurora forecast honestly falls back to a Kp-driven nowcast with reduced lead time, and Bz-dependent storm triggers are paused and labelled — we show the degraded state instead of hiding it. Ambient Mode — a living aurora The signature experience: a full-screen, data-reactive ambient that means something. One derived intensity drives everything — calm teal when quiet, brightening greens as activity builds, a magenta-violet push in a real storm. Pick your scene: a 3D aurora globe with the live OVATION oval over Earth's night side (australis first), the live Sun from NASA SDO, or a flowing solar-wind field. On Apple TV it's the lean-back living-room hero; on iPhone you can AirPlay or screen-mirror it to any TV. Built to run for hours with burn-in and thermal care — and it always eases to a calm fallback rather than fake a storm from stale data. Aurora australis, first-class Most aurora apps treat the Southern Hemisphere as an afterthought. Heliograph renders aurora australis first, alongside borealis — a real polar map with the auroral oval, local darkness/terminator, and your own viewline, plus a forecast scrub over the next 90 minutes. A "where do I go tonight?" ground map shows the visibility line across your region and how far toward the pole you'd need to travel. The infrastructure-impact lens Heliograph translates the current storm level into plain-language impact on what storms actually touch: the power grid (geomagnetically induced currents), GPS/GNSS accuracy, and HF radio. A world impact map places those effects on the day/night globe (colour-blind-safe). It is deliberately non-alarmist — most days, even minor storms, pass with no noticeable effect, and the app says so. Storm tracking & alerts A quiet → watch → storm state machine reads solar wind and Kp and shows exactly which triggers fired, with a Sun → L1 → Earth cinematic of the real arrival lead time. On iPhone, while you have Heliograph open, a storm Live Activity surfaces a significant storm on your Lock Screen — no account, no tracking. You can also opt into on-device "aurora likely tonight" alerts. On every surface: Lock Screen and StandBy widgets, a Control Center control, plain-language explainers, a colour legend, and a recent-activity solar time-lapse. Privacy, by design No account. No analytics. No tracking. No third-party SDKs. Data is fetched directly from public NOAA and NASA endpoints — Heliograph runs no servers of its own and stores nothing about you. Your location, if you grant it, is used only on-device to draw your aurora viewline — never stored or sent anywhere. Data sources NOAA Space Weather Prediction Center (SWPC) — SOLAR-1 at L1, the GOES satellites, and ground stations — plus NASA SDO solar imagery via the Helioviewer Project. Heliograph is not affiliated with or endorsed by NOAA or NASA. Ambient Mode includes solar imagery, hourly Moon visualization, latest published Earth photography, dated cloud and thermal-detection maps, Aurora Globe and Solar Wind. Image dates and source details are available in the app. These views are not live video or emergency warnings.

Mold does not grow because a room is humid. It grows on the one surface that is colder than the rest — a corner, a window reveal, the wall behind a wardrobe. The air touching that surface can sit at 97% while the middle of the room reads a comfortable 55%. Hygrometer works out what is happening on that surface, and tells you the humidity to keep the room under. WATCH A ROOM • Add the cold surface you are worried about: a corner, a window reveal, an uninsulated wall, single or double glazing • See the humidity at that surface, not just in the room • Get the limit for the room, worked out from the surface temperature and the weather outside • That limit moves with the forecast — the same wall tolerates 73% on a mild day and 41% in a cold snap THREE WAYS TO GET THE NUMBERS • A HomeKit humidity sensor, read automatically — Eve Room, Aqara, SwitchBot, Netatmo and others • Typed in from your own hygrometer, whenever you check it • Or neither: Hygrometer estimates the likely range from the outdoor conditions and how the room is used, using the EN ISO 13788 humidity classes. Shown as a range, never as a measurement of your room WARNINGS THAT ARRIVE IN TIME • Mold risk when the surface reaches 80% humidity, which is long before anything looks wet • Condensation when the surface falls below the dew point • And before either: a colder forecast tonight pulls the limit down, so the warning comes before the surface turns, not after SHOULD YOU OPEN THE WINDOW? The answer relative humidity gets backwards. Airing out only dries a room when the outdoor air carries less water in absolute terms. In winter it nearly always does, even at 90% outside. On a warm humid day it often does not, and opening a cool room makes it damper. Hygrometer compares both sides in g/m³ and names the driest hour of the day. THE OUTDOOR INSTRUMENT • Outdoor relative humidity on a 0–100% analog dial with comfort bands • Dew point, absolute humidity in g/m³, mixing ratio, pressure and conditions • 24-hour humidity chart • Home Screen and Lock Screen widgets, which fetch their own reading rather than waiting for you to open the app ALSO • Follow your location, or search any city worldwide • °C / °F throughout • Eight languages • No account, no tracking, no ads Outdoor readings come from Apple Weather. Indoor readings come from your own sensor or from you — iPhone has no humidity sensor, and this app never pretends otherwise. Weather data provided by Apple Weather.