Self-Hosted Weather Radar

Features

Quick Start

Deploy your own instance with Docker in about a minute:

git clone https://github.com/JoshuaKimsey/LibreWXR.git
cd LibreWXR
cp .env.example .env
docker compose pull
docker compose up -d

The published image (ghcr.io/joshuakimsey/librewxr) runs a data-pipeline service beside a pool of render workers that share state via memory-mapped files. Tile rendering scales across every core with no GIL bottleneck. The defaults — 16 render workers, with 12 GB pipeline and 18 GB renderer memory caps — target a multi-core host; set LIBREWXR_WORKERS and the compose memory limits in .env for a smaller box.

Building from a checkout instead: docker compose up -d --build.

Either way, the server starts serving tiles immediately and historical frames backfill in the background.

Older COMPOSE_PROFILES=single deployments keep working as a compatibility alias (1 render worker, legacy cache defaults).

Using the API

LibreWXR exposes a Rain Viewer v2 compatible API, plus a few extensions of its own (weather alerts, lightning strikes, motion arrows, live push updates over WebSocket, an MCP server for AI agents). Point any Rain Viewer client at your instance:

# Metadata endpoint (timestamps + tile paths)
GET https://api.librewxr.net/public/weather-maps.json

# Radar tile
GET https://api.librewxr.net/v2/radar/{timestamp}/{size}/{z}/{x}/{y}/{color}/{smooth}_{snow}.png

# Satellite tile (NOAA GMGSI VIS-over-LW composite)
GET https://api.librewxr.net/v2/satellite/{timestamp}/{size}/{z}/{x}/{y}/0/0_0.png

# Weather alerts (GeoJSON FeatureCollection — global by default, lat+lon, or bbox)
GET https://api.librewxr.net/v2/alerts
GET https://api.librewxr.net/v2/alerts?lat=39.7&lon=-104.9
GET https://api.librewxr.net/v2/alerts?bbox=-95,30,-90,35

# Lightning strikes (GeoJSON FeatureCollection — full window, lat+lon+radius, or bbox)
GET https://api.librewxr.net/v2/lightning
GET https://api.librewxr.net/v2/lightning?lat=39.7&lon=-104.9
GET https://api.librewxr.net/v2/lightning?bbox=-95,30,-90,35

# WebSocket push channel (live updates -- topics: weather-maps, alerts, storm-cells, lightning)
WS wss://api.librewxr.net/v2/ws?topics=weather-maps

# Health check
GET https://api.librewxr.net/health

# MCP server endpoint (Model Context Protocol -- AI agents, JSON-RPC over HTTP)
POST https://api.librewxr.net/mcp/

For Leaflet, the tile URL pattern is:

# Radar tiles
https://api.librewxr.net/v2/radar/{timestamp}/256/{z}/{x}/{y}/10/1_1.png

# With motion arrows (light for dark maps, dark for light maps)
https://api.librewxr.net/v2/radar/{timestamp}/256/{z}/{x}/{y}/10/1_1.png?arrows=light

# With storm-cell overlay (detected cells + motion arrows at each centroid)
https://api.librewxr.net/v2/radar/{timestamp}/256/{z}/{x}/{y}/10/1_1.png?cells=light

# With lightning strikes (dots or bolt glyphs, drawn on the frame they happened in)
https://api.librewxr.net/v2/radar/{timestamp}/256/{z}/{x}/{y}/10/1_1.png?lightning=dots

# Combined: motion arrows + storm cells
https://api.librewxr.net/v2/radar/{timestamp}/256/{z}/{x}/{y}/10/1_1.png?arrows=light&cells=light

# Satellite tiles (timestamps from satellite.infrared in metadata)
https://api.librewxr.net/v2/satellite/{timestamp}/256/{z}/{x}/{y}/0/0_0.png

See the full documentation for a web integration guide, configuration reference, and Rain Viewer migration instructions. Try the interactive examples to see LibreWXR in action, or browse the source on GitHub.

Data Sources

Radar composites:

• NCEP MRMS — Multi-Radar/Multi-Sensor quality-controlled radar composites (US regions + Canadian radar ingest, default source)
• Iowa Environmental Mesonet (IEM) — NEXRAD radar composites (US regions, fallback for MRMS)
• ECCC MSC GeoMet — Canadian weather radar composite
• EUMETNET OPERA — Pan-European radar composite via MeteoGate (184 radars, 27 countries). Italy is not in the OPERA station list, so Italian airspace is covered separately by DPC below.
• DPC (Dipartimento della Protezione Civile) — Italian national VMI composite (24 radars: 11 DPC-direct C-band & X-band + 13 partner radars from regional ARPAs, PAA Trento, ENAV, Aeronautica Militare). Open Radar-DPC v2 REST API, 5-min cadence, GeoTIFF format, attribution "Radar-DPC" required under CC-BY-SA 4.0
• MARN / SNET — El Salvador San Andrés radar 120 km product (Servicio Nacional de Estudios Territoriales), reproduced with attribution per MARN's open-data terms
• CWA QPESUMS (Taiwan) — Central Weather Administration 7-radar composite reflectivity product O-A0059-001, licensed under the Open Government Data License v1.0
• JMA HRPN (Japan) — Japan Meteorological Agency High-Resolution Precipitation Nowcast (気象庁ナウキャスト), 20 C-band Doppler radars + AMeDAS rain-gauge network composited as gauge-corrected QPE. Analysis leg only; JPCOMP nowcast frames come from LibreWXR's internal optical-flow extrapolation blended with JMA MSM as the regional model overlay. Ingested under the JMA Public Data License v1.0 (CC-BY equivalent, commercial reuse explicitly permitted with attribution to the Japan Meteorological Agency)
• MET Malaysia — Jabatan Meteorologi Malaysia 12-radar national composite covering Peninsular Malaysia, Borneo, Brunei, Singapore, and N. Sumatra, licensed under CC-BY-4.0 (Radar data © Jabatan Meteorologi Malaysia / METMalaysia)
• PAGASA — Philippine Atmospheric, Geophysical and Astronomical Services Administration (DOST) 9-radar PANAHON national mosaic covering Luzon, Visayas, and Mindanao. Public domain per Philippine IP code RA 8293 §176 (attribution: PAGASA / DOST)

Regional NWP models (layered ahead of the global ECMWF IFS model layer):

• NOAA HRRR — CONUS (3 km, 15-min subh) + Alaska (3 km, hourly) via NOAA Open Data
• ECCC HRDPS-Continental — 2.5 km rotated lat/lon, covers Canada and the northern fringe of CONUS
• DMI HARMONIE-AROME DINI — 2 km LCC, covers most of populated Europe via AWS Open Data
• DWD ICON-EU — ~7 km, fills the European remainder DINI doesn't reach
• Météo-France AROME Outre-Mer — 2.5 km, five overseas variants from the OVH Swift PNT distribution: Antilles (Guadeloupe + Martinique), Guyane (French Guiana), Indien (Réunion + Mayotte + Comoros + Madagascar + SW Indian Ocean), Nouvelle-Calédonie (New Caledonia + Vanuatu), and Polynésie (French Polynesia)
• SMN Argentina WRF-DET — 4 km LCC, covers the South American Cone via AWS Open Data
• JMA MSM (Mesoscale Model) — 5 km regular lat/lon over Japan + Korean Peninsula + Taiwan + Yellow Sea, republished via the Open-Meteo AWS Open Data mirror. Pairs with the JMA HRPN radar composite to give Japan a real mesoscale NWP forecast instead of falling through to global IFS

Global observed layer (always-on):

• NOAA Enterprise Rain Rate (RRQPE) — satellite-derived observed precipitation (IR-based estimate), GLB-5 blend of geostationary IR rain estimates (inputs include GOES-East/West, EUMETSAT Meteosat-9/10, JMA Himawari-9), 10-min cadence, 60°S-70°N coverage, 0.04° stored (0.02° native). Ingested as a single global radar region at the bottom of the multi-region compositor, filling only pixels no finer radar claims. Because it is observed, not forecast, it serves past/current frames only; the models answer future/nowcast times. Attribution requested: "Precipitation data from NOAA Enterprise Rain Rate (RRQPE)"

Global model layer:

• ECMWF IFS via Open-Meteo — 9 km global precipitation and snowfall, the terminal model of the NWP chain and the model side of the nowcast blend. For past/current frames it fills only poleward of the RRQPE band, the fringe excluded by RRQPE's coverage polygon, and pixels where RRQPE declines (missed scans / stale store) (CC-BY-4.0)

Satellite imagery:

• NOAA GMGSI — Global Mosaic of Geostationary Satellite Imagery, composited by NESDIS from GOES-East, GOES-West, Meteosat-9, Meteosat-10, and Himawari-9. Longwave IR + visible channels rendered as a VIS-over-LW composite with natural day/night terminator. Hourly cadence; coverage to ±72.7° latitude

Weather alerts:

• WMO Severe Weather — Global CAP weather alerts, polled every 5 minutes
• MeteoAlarm — European geocodes for resolving regional alert polygons
• NWS Alerts API — Used for US point lookups to surface non-polygon alerts (Tornado Watches, etc.)

Lightning:

• NOAA GOES-R GLM — Geostationary Lightning Mapper total-lightning flash points from GOES-East + GOES-West, ingested from the anonymous NOAA Open Data Dissemination (NODD) S3 buckets. US public domain; attribution requested: "Lightning: NOAA GOES-R Geostationary Lightning Mapper (GLM)"

All data sources are freely available from government-funded institutions. ECMWF IFS data is provided by Open-Meteo under the CC-BY-4.0 license.

Data Licensing

API Data (CC-BY-4.0, with one carve-out) — Radar data, satellite tiles, and all other data served by the public LibreWXR API at api.librewxr.net is available under the Creative Commons Attribution 4.0 International (CC-BY-4.0) license. You are free to use, share, and adapt this data for any purpose, including commercial use, provided you give appropriate credit to LibreWXR. The underlying data from government agencies (NCEP MRMS, IEM, ECCC, EUMETNET OPERA, MARN/SNET El Salvador, CWA Taiwan, JMA Japan, MET Malaysia, PAGASA Philippines, NOAA RRQPE, ECMWF IFS, NOAA GMGSI, NOAA GOES GLM) is public domain or freely available under their respective terms — the CC-BY-4.0 license applies to the aggregated composite data as served by this API instance, not to the original government data.

Italy (ITCOMP region only) is the exception: tiles that include native Italian radar data from DPC inherit the upstream CC-BY-SA 4.0 share-alike obligation. If you redistribute or build derivative works from DPC-derived tiles, you must do so under the same CC-BY-SA 4.0 terms and credit "Radar-DPC" as the data source. This is the only source in the LibreWXR stack with a share-alike clause; every other layer is permissive.

Software (AGPL-3.0-or-later) — The LibreWXR software itself is licensed under AGPL-3.0-or-later. If you modify and host LibreWXR, you must make your source code changes available under the same terms.

Self-Hosted Instances — You may choose your own data licensing terms for data served by your own LibreWXR instance. The AGPL-3.0-or-later license for the software applies regardless.

Open Source

LibreWXR is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0). Contributions are welcome on GitHub.

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