Compare free Prepar3D weather engines including FSrealWX, FSXWX and VFR Weather Companion, with version checks, limitations and setup fixes.
The main free Prepar3D weather options are FSrealWX and FSXWX for live METAR-based injection, plus VFR Weather Companion for generated themes and offline scenarios. Prepar3D also includes manual weather and preset themes. Support depends heavily on the P3D major version, so never assume a freeware engine labelled “P3D compatible” supports every release.
Which free Prepar3D weather option should I choose?
Choose FSrealWX or FSXWX for live airport observations; choose VFR Weather Companion when you want controlled, repeatable conditions without depending on a live data service.
| Option | What it provides | Best used for | Main limitation |
|---|---|---|---|
| FSrealWX | Live METAR-based weather injection | Matching real airport observations during a flight | The exact build, simulator connector and internet weather feed must all remain compatible |
| FSXWX | Lightweight live-weather injection | Simmers whose documented Prepar3D and SimConnect combination is supported | Compatibility claims attached to older downloads may not cover later P3D releases |
| VFR Weather Companion | Generated themes, forecasts, storms and visibility conditions | VFR practice, poor-weather training and repeatable scenarios | It is a weather generator rather than a continuously updating global live-weather service |
| Prepar3D weather controls | Manual conditions and included themes | Circuit practice, instrument approaches and fixed training scenarios | No automatic live METAR injection |
You can download the P3D-compatible VFR Weather Companion from our library. For broader comparisons that include commercial products, our side-by-side guide to live-weather programs explains the differences between Active Sky, REX, FSrealWX and similar tools.
Will free weather engines work with Prepar3D v4, v5 or v6?
A free engine will work only when its specific build supports that Prepar3D generation; a generic P3D compatibility label is not enough.
Prepar3D v1–v3 are 32-bit applications, while v4 and later are 64-bit. That distinction is critical for modules loaded inside the simulator. A separate weather program using SimConnect may cross that boundary, but only when its connector and protocol support the installed P3D release.
- Check the named P3D major versions, not merely “FSX/P3D compatible”.
- Confirm whether the program needs a particular legacy
SimConnectcomponent. These components can normally exist side by side; replacing DLL files manually is not a safe fix. - Verify that the live-data service still supplies fresh observations. An old injector can connect perfectly to Prepar3D while receiving no usable weather.
- Remember that weather injection and cloud rendering are separate. A tool may inject valid pressure, wind and visibility data without supplying new cloud textures or sky colours.
Our Prepar3D weather-engine installation and configuration steps cover SimConnect, update intervals and conflict prevention without requiring risky changes to the simulator installation.
Why does the engine connect but show no weather?
A connected status with unchanged conditions usually means the data feed is stale, another injector is taking control, or the loaded scenario has overwritten the injected weather.
- Run only one injector. Close every other live-weather utility, including programs bundled with broader environment packages.
- Check the observation time. If the reported METAR is missing or several hours old, the problem is upstream of Prepar3D.
- Confirm SimConnect communication. Use the connector required by that engine and P3D version rather than copying random SimConnect files into the simulator folder.
- Load the flight before injecting. A saved scenario can restore its own weather after an engine has already sent conditions. Once the aircraft is loaded, request a fresh update.
- Test at a reporting airport. Compare pressure, wind and visibility against that station’s METAR. Remote areas may rely on interpolation and will not always reproduce a nearby report exactly.
- Check security software. A firewall may allow the application to launch while blocking its internet weather feed or local SimConnect traffic.
What do free weather engines leave out?
Free Prepar3D weather engines generally lack the smoothing, detailed upper-air modelling, planning integration and continuing compatibility work found in established commercial packages.
They also do not automatically improve cloud models, textures or lighting. FSrealWX and FSXWX mainly inject atmospheric data; visual appearance still comes from Prepar3D and any separate environment add-ons. For training flights and basic live conditions, that may be sufficient. For long-haul flying, rapidly changing fronts or strict version support, confirm those capabilities before choosing an engine.