The Dark Sky Alternative for iPhone, Mac, and the Web
What happened to Dark Sky
Dark Sky was the weather app that taught the world to expect a minute-by-minute precipitation forecast. Apple acquired it in March 2020. The Android app went away first; the iOS app and its widely-used developer API followed by early 2023. The minute-by-minute block lives on inside Apple Weather, but the rest - the geeky model commentary, the open API, the no-frills UI - did not survive the move.
If you landed here, you are probably one of three people. You used the Dark Sky app, you miss the way it told you it was about to rain in eight minutes, and you want that experience back. Or you had a Dark Sky API key wired into a side project that broke. Or you write code professionally and Dark Sky's shutdown removed the only weather source you trusted.
GrayCloud is built for all three.
What GrayCloud does
- Minute-by-minute precipitation - a 60-minute precipitation forecast generated by GrayCloud's proprietary in-house nowcasting engine, running against a national radar feed at higher resolution than Dark Sky's source.
- Hourly conditions for 48 hours. Temperature, feels-like, wind, dew point, UV, pressure, visibility - the geeky data plate Dark Sky users came to expect, laid out as a single scrollable page.
- 10-day outlook driven by GrayCloud's proprietary multi-model forecast engine, with bias correction trained nightly against observed surface stations.
- Global radar globe. A live radar layer with station overlays you can tap for the raw observation, expandable to full-screen.
- Time Machine. Look up the weather for any address and any date - past or future. The same historical and projected lookup Dark Sky users relied on for trip planning, project archives, and post-mortems.
- iPhone, iPad, Apple Watch, Mac, and web. iPhone and iPad are free to download; the web app is free and works in any browser. GrayCloud Member ($8/year) unlocks Live Activities, widgets, custom rain alerts, and live radar maps; the All-platforms Bundle ($20/year) is required for the Apple Watch app and the macOS app.
- Drop-in API shape for developers. GrayCloud's backend already speaks Dark Sky's JSON dialect; the public API tier is on the roadmap.
How the forecast actually gets made
Most consumer weather apps wrap a single commercial provider and present its output as if it were a single source of truth. GrayCloud doesn't. The forecast you see comes from a proprietary multi-model engine built on top of best-in-class numerical weather data, with an in-house nowcasting layer for minute-by-minute precipitation.
The pipeline is bias-corrected nightly against observed surface stations, and we publish a public forecast accuracy scoreboard so the calibration is auditable. If GrayCloud's high temperature for your zip code was off by four degrees yesterday, that miss is in the record. Most weather apps quietly walk back bad forecasts in the rear-view mirror; GrayCloud puts the receipts on a page anyone can check.
Privacy: no tracking, no ads, no accounts
GrayCloud has no user accounts, no third-party analytics, no advertising SDKs, and no data sold or shared. The iOS and Mac apps store your saved places in your private iCloud Key-Value Store (so they sync between your devices without ever touching a GrayCloud server). The web app uses Cloudflare's first-party traffic counter, which does not set cookies and does not fingerprint visitors. No location history is retained.
This is the default. There is no premium privacy tier and no toggle to find buried in settings.
How it compares
If you are evaluating GrayCloud against another Dark Sky alternative, these head-to-heads go into more detail:
- GrayCloud vs Dark Sky - feature-for-feature, including what Apple Weather kept and what it dropped.
- GrayCloud vs Apple Weather - what Apple kept, what they didn't, and where GrayCloud still beats the default.
- GrayCloud vs Tomorrow.io - the commercial alternative most ex-Dark Sky developers ended up testing first.
The honest tradeoffs
A few things GrayCloud does not do yet, on purpose:
- No global minute-by-minute. Our radar nowcasting is a United States product today. If you are outside the US you still get a competent hourly and daily forecast from the global outlook, but the precipitation nowcast cuts off at the border. International coverage is on the roadmap.
- No social, gamification, or news feed. GrayCloud is a weather page. You open it, you see the weather, you close it.
Frequently asked questions
Is GrayCloud free? GrayCloud is free on iPhone and iPad — the native app includes minute-by-minute rain, address-level forecasts, the 7-day outlook, and multiple saved locations, with no account or tracking. GrayCloud Member ($8/year) adds Home Screen and Lock Screen widgets, custom rain alerts and lifestyle notifications, live radar maps, and Live Activities. The All-platforms Bundle ($20/year) is required for the Apple Watch app and the macOS app.
Does GrayCloud do minute-by-minute precipitation like Dark Sky did? Yes. GrayCloud generates a 60-minute precipitation forecast using a proprietary in-house nowcasting engine, running against a national radar feed at higher resolution than Dark Sky's source.
Does GrayCloud track me? No. There are no accounts, no third-party analytics, no advertising SDKs, and no data sold. The web app uses Cloudflare's privacy-friendly traffic counting; the iOS and Mac apps store saved places in your private iCloud Key-Value Store.
Where does GrayCloud get its forecast? GrayCloud runs a proprietary multi-model forecast engine. It blends high-resolution short-term modeling, global medium-range modeling, an in-house nowcasting layer built on a national radar feed, and observations from personal weather stations near you. The pipeline is bias-corrected nightly against surface stations, and the calibration is published on a public scoreboard.
How accurate is GrayCloud, really? The nightly forecast accuracy scoreboard is the answer to that question, not anything we could put on a marketing page. Plug in your zip code and see the rolling 30-day error. Temperature, precipitation, and severe-weather skill are graded against observed conditions every night.
Does GrayCloud work outside the United States? Partially. The global medium-range outlook returns a forecast for any address worldwide, but the minute-by-minute precipitation block (which relies on a national radar feed) is United States only today. Europe and Canada coverage is on the roadmap.
Will there be a Dark Sky-compatible API? Yes. A paid API tier with a Dark Sky-shaped JSON response is on the roadmap. The backend already returns the Dark Sky JSON shape internally, so existing integrations can swap the endpoint without rewriting parsers when the public tier opens.
Is GrayCloud actually built by one person? Yes. The backend forecast pipeline, the iOS and Mac apps, and the web all ship from the same author. Support email goes to a human.
Get GrayCloud
Or try the web app first - type an address at /forecast and you will get the same forecast the iOS app shows, in any browser, with nothing to install.