iPhone and iPad · NOAA GOES satellite lightning
Do we come off, and when can we go back?
Every other lightning app shows you a map of dots and leaves the decision to you. Lightning Alarm watches a radius around a place you saved and runs the all clear clock itself. Every new flash inside the ring starts it over, so nobody heads back out five minutes early.
Free, with no ads.
Pro is one payment of $7.99.
Four states for a saved place. The grey one never shows up green.
The two questions
You are the one who has to make the call
Coaches and referees. Pool managers and lifeguards. Golf course staff, grounds crews, construction supervisors, marina and airfield staff, camp directors. Anyone standing in front of a group that is waiting to be told what happens next.
01
Do we come off?
A flash lands inside your ring and the status flips to SUSPENDED. Your radius is evaluated on a server, not on the handset, so the alert arrives with the app closed, the phone locked, or the app force quit. You never have to leave a map open and watch it.
02
When can we go back?
The all clear countdown runs on the status screen and restarts on every new flash inside the ring. That restart is the half nobody automates. Running it in your head, during the one moment you are busiest, is how a group goes back outside too early.
On the phone
An instrument, not a weather app with a personality
Readable on a fairway at noon and on a pool deck at dusk. One rule holds the palette together: that yellow is spent on lightning and on nothing else, so a flash of it always means the same thing.
What it does
Built around the decision, not around the map
The alarm runs on a server
The geofence is evaluated off the device, so the push lands with the app closed, the phone locked, or force quit. Measured at roughly a minute from the flash reaching the satellite feed to the phone.
Distance as a range, never a false decimal
Satellite lightning is located to within a few miles, so the app says "within 6 mi to the NNW" instead of inventing a street corner. A flash whose footprint touches your ring counts as inside it, which can suspend a few minutes early. That is the correct direction to be wrong in.
Rules that match your policy
Presets for school sports, golf, pool, jobsite and boating, or set your own. Type the radius in miles or kilometres and set the all clear window to whatever your league or your insurer already requires.
A live map that admits what it knows
Each flash is drawn as a disc the size of the sensor's real uncertainty, with your policy ring on top. Nobody gets a confident dot on a driveway that the satellite could not have resolved.
The record afterwardsPRO
Every closure logged with times, closest approach, flash count and near miss count, exportable as CSV. What you hand an athletic director or a site manager when they ask why the field was empty for forty minutes.
Radar that says how old it isPRO
National Weather Service base reflectivity under the flashes, with the scan time on screen in every state. A layer that quietly stops updating looks exactly like a sky with no rain in it, so this one switches itself off when the feed goes stale.
Pricing
The alarm is never behind the paywall
An app whose whole argument is that people go back outside too early cannot charge for the thing that stops them. Pro sells scale and paperwork instead: more sites, the record, the radar context, and not being woken at 2am on a day off.
Free
$0NO ADS, EVER
- One saved place with a real server side push alarm
- Status, all clear countdown, nearest activity, bearing and trend
- Live satellite flash map, every flash at its true uncertainty
- A radius you type in, in miles or kilometres
- Rule presets for school sports, golf, pool, jobsite and boating
Lightning Alarm Pro
$7.99ONE PAYMENT
- More than one place, each with its own rule and radius
- Incident log with times, closest approach and flash counts
- CSV export of the whole log
- NWS base reflectivity radar under the flashes
- Quiet schedule, so a jobsite does not wake you on a day off
Everything in Free stays in Free. Pro is a one time unlock, not a subscription.
Where the data comes from
What this app will not claim
This is a safety tool, so the limits belong on the front page rather than in a support article.
- In cloud and cloud to ground
- Flashes come from the Geostationary Lightning Mapper aboard NOAA GOES-East and GOES-West. It sees total lightning, in cloud as well as cloud to ground, and it cannot tell the two apart. This app never claims that it can.
- Coverage
- The satellites cover the Americas and the nearby oceans. Outside that field of view a place reports NO COVERAGE, in grey, rather than a reassuring green screen. The radar layer is National Weather Service data and is United States only.
- Position is an estimate
- The sensor footprint is several miles across, so a reported position is an area and not a point. The app draws it that way, phrases distance as a band, and treats a flash whose footprint overlaps your ring as inside it.
- It supports the call, it does not make it
- Lightning Alarm is a decision aid. It does not replace your organisation's safety policy, an on site detector, or your own eyes on the sky.
Save a place, set your radius
Then let it watch
Free with no ads, one saved place, and the same server side alarm the paid tier gets.