Frequently asked questions

The watch face is the always-on forecast ring you wear all day. The watch app is where you explore: scrub through the ring hour by hour, switch temperature/rain/wind views, and change settings. The app also feeds the face its weather — install both for the full experience.

Tip: when the app opens, a brief gold Sunlight flourish appears before the status line — that's how you know you're in the app, not on the face.

On Wear OS 6 or newer, the Krona Sunlight app offers to install the face directly — one tap, no separate download.

On Wear OS 5, install the free "Krona Sunlight Watch Face" from Google Play separately, then pick it in your watch's face picker.

Yes — the watch app fetches weather on its own over Wi-Fi or LTE, so the face stays current even when your phone is off or away. The phone app adds convenience: bigger forecast view, widgets, settings that sync both ways, and it's where a Premium subscription is purchased.

No. There are no accounts, no sign-ups, no email addresses — not even for Premium (that's handled entirely by Google Play). See the privacy question below for what little the service knows about you.

Almost nothing, by design. Each install gets a random anonymous ID, and weather requests carry your location rounded to about a kilometer — the service stores only a ~5 km grid cell for statistics, purged automatically after 90 days. No name, no email, no advertising ID, nothing sold or shared.

Two transparency notes. Normally every Basic and Premium request flows through Krona's servers — that's what keeps the anonymous-ID model airtight. But if our service can't be reached (an outage on our side, or your device briefly offline), the app makes an emergency fallback fetch directly to Open-Meteo so the ring never goes dark — it sends only the same ~1 km-rounded coordinates, no ID at all. And Custom-plan users always talk directly to OpenWeatherMap by design, with their own key.

You can delete your data yourself anytime using the Data ID shown in the app's About screen. Full details in the Privacy Policy.

Depends on your plan:

• Basic Open-Meteo — open, model-based forecasts with worldwide coverage. Free, no account.
• Premium Apple Weather — the same data source Apple's own weather app uses, including radar-based minute-by-minute rain.
• Custom OpenWeatherMap, fetched directly from your device with your own API key.

Whatever the plan, the ring works the same — the providers differ in freshness and rain detail.

There's also a safety net: if Krona's servers are ever unreachable, the app fetches basic Open-Meteo weather directly from your device as an emergency fallback — so a hiccup on our side never leaves your watch without a forecast. The app's debug log labels these fetches explicitly.

Premium's minute-by-minute rain for the next hour is built from live precipitation radar, so it only exists where a radar network feeds us. We combine several sources — each processed differently, but the app always shows one seamless thing: rain, minute by minute, for the coming hour.

Elsewhere (France, the Netherlands, …) there is no radar source yet — Premium still gives you fresher, higher-quality forecasts, and the next-hour view falls back to model-based rain. The list grows over time.

The watch refreshes on a regular cadence (about every 15 minutes with default settings). What differs is how fresh the data itself is:

• Premium served data is at most ~10 minutes old — the minute-rain view tracks the radar nearly live.
• Basic forecasts may be up to a few hours old. Weather models themselves update roughly hourly, so day-planning accuracy is barely affected — you mostly notice the difference in short-term rain.

Basic is free, forever, with no account and no ads. You get the full Krona Sunlight experience:

• The 24-hour forecast ring on the watch face and in the apps
• Hourly temperature, feels-like, wind, gusts, cloud cover and conditions
• Rain amounts in 15-minute steps (model-based)
• 3-day forecast, sunrise/sunset, complications, phone app

Premium changes where the data comes from — not which features you're allowed to see.

• Apple Weather data — without needing an Apple account or API key
• Minute-by-minute rain for the next hour, radar-based in covered regions
• Fresher updates — served data at most ~10 minutes old
• Phone home-screen widgets

$2.99/month or $17.99/year, both with a 7-day free trial. Subscribe once in the phone app — the watch unlocks automatically. Cancel anytime on Google Play; you keep Premium until the period ends.

Custom is for people who already have an OpenWeatherMap API key (or want full control over their data source). Paste your key into the app's plan settings and your devices fetch weather directly from OpenWeatherMap — Krona's servers are not involved at all.

Custom is free in Krona; OpenWeatherMap's own pricing applies to your key.

It depends on your OpenWeatherMap subscription:

• With a One Call 3.0 key you get a 1-minute rain nowcast for the next hour plus 48 hours of hourly forecast. Nowcast quality varies by region and is generally a step below Premium's radar feed.
• With a free-tier key (no One Call) the app falls back to OWM's 5-day/3-hour forecast — the ring still works, but without minute rain and with coarser steps.

The app tells you which mode your key runs in right after you paste it.

The second Krona watch face, currently in development: tides and sea state, all day, at a glance. Where Sunlight wraps your weather day around the dial, Tidewater wraps the water — when high and low tide fall, how big the waves are, and how warm the sea is. Made for beach days, surfing, sailing, paddling, and fishing.

The design in progress pairs two rings:

• A tide ring — the day's water-level curve around the 24-hour dial, with high/low markers and times, over the same day/night arc you know from Sunlight (so you can see at a glance whether low tide falls in daylight).
• A sea-state ring — wave height around the day, with water temperature woven in as the ring's color.

Details may still change before release.

Tide predictions are astronomical harmonic calculations — the same method printed tide tables use — based on a worldwide network of tide stations plus global ocean-tide models between stations.

The astronomical part is extremely reliable — near a reference station, high and low tide times are typically accurate to minutes. But weather rides on top of astronomy: storm surge, strong onshore winds, unusual air pressure, and river discharge can push the actual water level noticeably above or below the prediction. Never rely on tide predictions alone where water levels are safety-critical.

From Open-Meteo's marine service, which serves named, documented wave models — Météo-France MFWAM, ECMWF WAM, DWD and NOAA wave models — choosing the finest model available for your location. Water temperature comes from satellite-based sea-surface analyses. The same transparent-source philosophy as Sunlight's weather data.

No — and deliberately so. Wind is an atmospheric product, and you already get it from your weather plan's source: Basic Open-Meteo, Premium Apple Weather, or Custom your OpenWeatherMap key. Tidewater shows the same wind as Sunlight — one wind, whichever face you're on.

Tidewater is its own optional subscription — $2.99/month or $17.99/year with a 7-day free trial — independent of Sunlight Premium: you won't need one to use the other, and both live in the same Krona apps.

Waves and water temperature cover all oceans. Tide predictions work along coastlines worldwide, with the densest station coverage in North America, Europe, Australia & New Zealand, and Japan; between stations, global tide models fill in.

It's in active development. Release news lands on this site and on the Google Play listing — no dates promised until it's genuinely close.