Public warning data, watched around the clock.
The Nuclear Watch Dog keeps watch on the radiation monitors and seismic sensors the US government already publishes, across the whole country, day and night. It turns them into one clear picture, and sends an alert to a phone and an inbox the moment something crosses a line.
What Watch does
Watch is the private monitoring page behind the icon in the top-right corner. It brings together everything below, updates itself while it's open, and keeps checking on the server even when it isn't.
Nationwide radiation alarm
Every EPA RadNet air monitor in the country, about 140 live stations in all 50 states and Puerto Rico, checked against an alarm level.
- An alarm names the city and state, and how far away and in which direction it is.
- A map of every monitor, coloured by how far each is above its own normal.
- A separate warning when a monitor climbs to a set multiple of its normal level.
Regional radiation charts
Hour-by-hour charts for every EPA monitor in Tennessee, Arkansas, Oklahoma and Texas, plus the neighbouring states upwind of the region.
- Each monitor is drawn against its own 30-day normal, so a real rise stands out.
- 48-hour, 7-day and 30-day views, in dose rate or percent of normal.
- A full hour-by-hour table, downloadable as a spreadsheet, and a saved copy whenever an alarm trips.
Seismic watch
Every earthquake USGS reports, filtered to what matters, with alert rules that look for the signatures of an explosion.
- Shallow and strong events: the pattern an explosion makes.
- Anything near a known nuclear test site, anywhere in the world.
- Events USGS classifies as an explosion, including later relabels.
- A missile-field strike pattern: many shallow events at once in an ICBM field, sent as one urgent alert.
Threat levels
The public indicators for the USA, Europe and Japan in one place, each labelled with who publishes it and whether it's official.
- DEFCON: why the real level is secret, with the best-known unofficial estimate clearly marked.
- DHS terrorism advisories, the UK threat level, and Japan's J-Alert.
- The Doomsday Clock.
Fallout wind watch
Where fallout would travel from the military targets nearest the region, using the forecast wind at the heights that carry it, updated every hour.
- A map with wind arrows and plume wedges, a 24-hour time slider, and a save-as-image button.
- A HIT / NEAR MISS / MISS verdict against a chosen evacuation route.
- The chance, hour by hour, that fallout would reach the route.
Estimated fallout, hour by hour
The standard US civil-defense fallout model (WSEG-10), run on the live forecast. It estimates the radiation level each town on the route would see in the 48 hours after a strike.
- Choose which targets, weapon size and time.
- The worst point on the route, and the total dose for someone caught outdoors.
Radiation health guide
What a dose actually does to the body, in plain language, based on CDC's clinical guidance.
- How long it takes to reach each dose at a given reading.
- A dose calculator: reading, time since the burst, how long, and where you're sheltering, from a car to a basement. It shows how much waiting and shelter reduce the dose.
Phone and email alerts
The server keeps checking even when nobody has the page open, and sends alerts straight to a phone app and an inbox.
- Setpoint blocks for every alarm type, each with its own levels and its own phone and email switches.
- Reminders while an alarm lasts, and an all-clear when it ends.
- No duplicates: each event is sent once.
When to leave
A decision board that puts personal triggers next to the live signals and gives one clear verdict: Normal, Get ready, Leave early or Shelter now.
- Printable checklists for each situation: leave early, shelter, and go when the route is clear.
How an alert reaches you
Nothing here depends on someone watching a screen.
Agencies publish
EPA posts hourly radiation readings; USGS posts seismic events within minutes.
The server checks
Every few minutes, day and night, against the levels you set.
Something crosses a line
The alert says what, where, how far away, and why it was flagged.
Your phone and inbox
A push notification and an email, sent once, with a link straight to Watch.
What it can't do
Every tool here is only as good as the public data behind it. Knowing the limits is part of using it well.
This is not an official warning system
Wireless Emergency Alerts on your phone, sirens and local radio come first. Follow official instructions.
EPA readings arrive an hour or more after they're taken. A monitor near an event may stop reporting. USGS only confirms an explosion after review, and a weapon exploded high in the air may not register on seismographs at all. Fallout estimates are models, and the real plume depends on the wind that day. Everything here needs the internet; it goes dark when the network does.
If a detonation happens, get into the middle of a solid building or a basement, away from windows.
At least 24 hours unless officials say otherwise. Fallout radiation fades fast: about 90% within 7 hours.
Battery radio, alerts on your phone. Move only when you know where the fallout is going.
From FEMA and ready.gov/radiation.
Where the data comes from
All public sources, credited on the pages that use them.
See an example
A working, public copy of Watch, running on the same live data, set up for a sample household in Knoxville, Tennessee, with three evacuation routes to Mena, Arkansas.
Everything Watch has: radiation, seismic, threat levels, fallout winds and the hour-by-hour fallout estimate for each route, modelled for the six targets around this corridor. Plus the health guide and the When to leave board.
Open the example →Your own private Watch, built around your home, your destination and your routes, with the targets that matter for your area and alerts to your phone and email.
Live drive times use TomTom's traffic data, so your Watch needs its own free TomTom key. It takes about two minutes, and we'll walk you through it.