Your calendar, weather-aware.

Rain Chk reads your calendar, checks the forecast for each event's actual time and place, and sends a short, specific heads-up before you need one — not a generic weather app notification, a prep tip for the thing on your calendar.

Free during the beta · iPhone · Requires TestFlight

The whole idea

Calendar in, prep tip out

Every other weather app makes you go check it yourself, for a place you have to remember to look up. Rain Chk skips that entirely.

1

Connect your calendar

Grant access to the calendars you want covered — reads directly from EventKit, entirely on-device, nothing uploaded anywhere.

2

Get a real forecast, automatically

For every upcoming event, Rain Chk resolves its location and pulls the actual forecast for that place and time — not just "today's weather."

3

A heads-up before you need it

A short local notification with what to expect and what to bring — only when the forecast is actually worth mentioning, timed to when it's useful.

Your calendar might say...
Kids' soccer game
10:00 AM – 11:30 AM, Dorey Park
↓ becomes ↓
Rain likely by 10:30am Bring a jacket Sent the night before Written on-device
Built for the whole day

More than a forecast

🧠

On-device message generation

Apple's on-device model writes every heads-up — plain, direct, and specific to your event, with a deterministic fallback if the model isn't available.

🔔

Notifications that know when to stay quiet

No ping for a calm, clear forecast — and a scheduled notification re-checks closer to the event, so its content never goes stale.

🌧️

Next-hour precipitation

A minute-by-minute rain chart for the next 60 minutes at any event's location — "rain starting in 12 min," not just a daily percentage.

📅

Multi-day trips, covered every day

A weekend trip or a multi-day event shows up — and gets a real forecast — on every day it spans, not just the day it starts.

🧩

Home-screen widget

Your next event's weather and prep tip, at a glance, without opening the app.

🚗

Traffic-aware timing

For an event coming up within the hour, a quick drive-time read alongside the forecast — so "should I leave now" has one answer, not two apps.

See it in action

Screenshots coming soon

Real screenshots from the app are on the way — for now, here's where they'll go.

Event list — forecast & prep tip per event
Event detail — next-hour rain chart
A prep notification, on the lock screen
Home-screen widget

Your calendar never leaves your phone

Calendar access stays on-device via EventKit, and Apple's on-device model writes every heads-up — only the event's coordinates and time go out, to Apple's own WeatherKit, to fetch the forecast. No third-party analytics, no ad tracking.

Rain Chk is in TestFlight now

It's early — the beta is small and invite-only right now. Invites aren't open yet, but check back soon.

Invites coming soon

Once a public TestFlight link is set up in App Store Connect, this button's href becomes https://testflight.apple.com/join/<your-code> and the copy changes to "Join the beta."