What is NukeMonitor?

NukeMonitor is a free, publicly accessible radiation and seismic monitoring platform that aggregates live data from government and volunteer sensor networks across the globe. Our goal is to make environmental radiation data understandable, searchable, and actionable — for everyone, without requiring specialist knowledge.

We do not operate our own sensors. We collect, normalise, and display data from independent monitoring stations worldwide, described below. All readings are presented as received, with threat-level classifications applied algorithmically to help contextualise the numbers.

NukeMonitor polls each data source on its own schedule — typically every 1–15 minutes depending on the network. The dashboard auto-refreshes every 60 seconds while open. Each station reading is timestamped with its actual fetch time, which you can see in the station list. Readings older than 12 hours are excluded from the live dashboard view.

Threat levels are assigned automatically based on the raw CPM value reported by the station. The µSv/h estimate uses a reference conversion factor of CPM × 0.00833 — appropriate for common Geiger-Müller tubes such as the SBM-20 and J305. Actual dose rate depends on the specific tube and any energy compensation, so treat µSv/h as an approximation only. When a station reads Monitor-level or higher and a nuclear power plant is within 100 km, NukeMonitor also checks current wind direction at the plant: if the station is downwind (within ~45° of the wind vector), this is noted as contextual information — wind direction matters when assessing whether a reactor could be a contributing source, but this is not a determination of cause.