FS2004 (FS9) Updated Mon, 26 Oct 2026 04:48:37 GMT 8 min read 270 views

How do I use real-world weather in FS2004?

By Ian StephensEditor-in-Chief

In short

Set up real-world weather in FS2004 with FSrealWX, FSUIPC 3 and a METAR weather injector, with fixes for stale reports and failed feeds.

FS2004’s built-in online real-world weather service has been retired, so its menu option no longer downloads live conditions. To use real-world weather in Microsoft Flight Simulator 2004 (FS9), run a compatible third-party METAR weather injector and connect it through the FS2004 edition of FSUIPC; otherwise use manually entered weather or an offline theme.

Which weather injectors still work with FS2004?

FSrealWX is the most practical free weather injector to try first, while licensed server-based products are usable only if their FS9 service still supplies fresh reports. An old programme launching successfully does not prove that its original weather endpoint still works.

Weather injector	FS2004 status	Registration requirement	Best use
FSrealWX	Obtainable freeware with an FS2004/FS9 mode; functionality depends on its selected METAR source	No FSrealWX licence or paid FSUIPC registration is required for a local connection; remote use through WideFS has separate requirements	Best free first choice when it returns a fresh UTC report
FS Global Real Weather (FSGRW)	FS9-compatible legacy editions use a server-fed service through FSUIPC 3; operation depends on a valid licence and working service	Requires its own commercial licence; normal local FSUIPC access does not require a separate paid FSUIPC user registration	An alternative for an existing licensed installation that demonstrably receives fresh data
FSMetar and similar early freeware utilities	The software remains obtainable, but hard-coded download addresses may return stale data or nothing	No product licence; packaged releases normally carry their own FSUIPC application access	Manual METAR work or testing only unless the report timestamp proves the feed is live
Active Sky 6.5 or Active Sky Evolution	Discontinued commercial products whose activation and original online services should not be treated as dependable	Requires the product’s own licence, not merely an FSUIPC registration	Existing installations only; not a dependable new live-weather setup

Freeware does not guarantee a surviving data service. Our comparison of simulator live-weather programmes explains the same distinction for other simulators and weather engines.

FSrealWX for FS2004

Yes, the obtainable FSrealWX package with an FS2004 or FS9 simulator profile supports FS2004. It requires the FSUIPC 3 branch; use the final FS9 build, FSUIPC 3.999z9, rather than FSUIPC 4 or a newer 64-bit branch.

Install FSUIPC 3 first: Confirm that FSUIPC.dll is in the FS2004 Modules folder and that its entry appears on FS2004’s Modules menu.
Select the correct simulator: In FSrealWX’s simulator or connection settings, choose FS2004 or FS9 and select the local FSUIPC connection. Do not choose FSX simply because it also uses an FSUIPC interface.
Choose an online METAR source: Source names vary between FSrealWX releases. Select an online provider rather than an offline file, then fetch one report and inspect its station code and DDHHMMZ timestamp before enabling injection.
Set automatic updates: An interval of about 15 minutes is suitable for FS2004. Requesting data every minute will not make routine half-hourly or hourly METAR observations newer.
Connect after loading the flight: Start FS2004, enter the cockpit, connect FSrealWX and then download and inject the weather. Leave FSrealWX running if continuing updates are required.
Control FS2004’s own changes: Set FS2004’s weather-change rate low or off when you want close agreement with the injected report. Otherwise the simulator may evolve the conditions between downloads.

A green or connected status proves only that FSrealWX can communicate with FS9. It does not prove that the weather source is live. If the selected source repeatedly returns an old report, try another source offered by that FSrealWX build and check the UTC timestamp again. If none is fresh, use a proven licensed FSGRW installation, manual weather or a theme rather than repeatedly injecting cached data.

Which FSUIPC version does FS2004 need?

FS2004 requires FSUIPC 3, with 3.999z9 being the final supported FS9 build.

Correct location: Install the module as <FS2004>\Modules\FSUIPC.dll. Do not put the weather programme in that folder, and do not substitute FSUIPC4.dll, FSUIPC 6 or FSUIPC 7.
Menu check: Run FS2004 and look for the FSUIPC entry under Modules. If it is absent, the DLL did not load.
Log check: Open Modules\FSUIPC.log after closing the simulator. It should identify the FS2004 session and show successful initialisation; after the injector connects, it should also show client activity.
Configuration check: FSUIPC normally creates FSUIPC.ini in the same folder. If neither the log nor configuration file appears, check folder permissions and confirm that the DLL is not buried inside a second Modules directory.
Registration: FSrealWX and recognised local applications use their own FSUIPC application access, so paid FSUIPC features are not required merely to inject weather. Running the injector on another computer through WideFS is a separate arrangement and requires the corresponding registered network component.

A common mistake we see is installing several weather products and allowing all of them to write to FS9. Use one source only; our guidance on improving FS2004 realism without conflicting add-ons covers that wider setup choice.

Weather injector and weather inject troubleshooting

Most failed weather injections are caused by an incorrect FSUIPC branch, mismatched Windows permissions, stale source data or a second programme overwriting the result.

Disconnected status: Load a flight before connecting. Confirm that FS9 shows FSUIPC on its Modules menu and that the injector is configured for FS2004 rather than FSX.
Administrator mismatch: Run both programmes at the same privilege level. The safest arrangement is normally to run both without administrator elevation; if FS9 must be elevated, start the injector the same way.
Old METAR timestamp: Read the group ending in Z. For example, 261250Z means the 26th day at 12:50 UTC. Compare UTC rather than local time, allowing for stations that report only hourly.
Conditions briefly appear and reset: Close every other weather engine and disable automatic injections from old add-ons. Only one programme should control the weather.
No weather at a small airfield: Many airfields do not issue METARs. Check the nearest reporting station and expect the injector to copy or interpolate its conditions.
ATIS does not match exactly: Wait for the local weather to populate, then compare wind, visibility and altimeter setting with FS2004 ATIS. Small differences can result from rounding, interpolation or FS9’s weather-change setting.
Wind appears misaligned with the runway: METAR wind direction is referenced to true north, while runway numbers use magnetic direction. Magnetic variation can produce an apparent discrepancy.

The downloadable legacy FS2004 METAR and upper-air utility is useful for experimentation, but treat it as live weather only after confirming that its source returns a recent observation. Buying or registering FSUIPC will not repair a retired download address.

How accurately does injected METAR weather match reality?

Injected weather represents the latest station observation, not a second-by-second picture of the atmosphere.

A METAR supplies surface wind, visibility, cloud, temperature, dew point and pressure for one reporting station. Routine reports are commonly issued every 30 or 60 minutes, with special reports between them when conditions change significantly. Upper winds require a separate source, and FS2004 approximates cloud structure, precipitation and transitions within the limits of its weather engine.

Present-day reports also remain present-day weather if the simulator clock is set to a historical date. Recreating an older flight requires an archived report or manually entered conditions.

What can I use when no live weather injector works?

Use an offline weather theme for route-wide conditions, or enter a known METAR manually when no compatible injector can obtain a fresh report.

Weather themes are not live, but they are reliable for training and offline flying. Search our freeware downloads library for FS2004 weather themes, then install the selected package according to its included instructions.

How do I enter a METAR manually in FS2004?

FS2004 cannot paste and decode a complete METAR string automatically, but its user-defined weather controls can reproduce the important groups.

Open the weather controls: In FS2004, open World > Weather and select user-defined weather.
Select the reporting area: Apply the weather globally for a simple exercise, or select the specific airport or nearest weather station for local conditions.
Enter the wind: Convert a group such as 27012G20KT to wind from 270 degrees at 12 knots, gusting to 20 knots.
Set visibility and cloud: Enter the reported visibility and recreate cloud groups such as BKN025 as broken cloud at 2,500 feet above the station. If an FS2004 field expects altitude above mean sea level, add the airport elevation.
Enter temperature and pressure: Copy the reported temperature and dew point where available, then set the altimeter from a group such as Q1016 or A3001, using the units selected in FS2004.
Verify in the cockpit: Tune the airport ATIS and compare its wind, visibility and altimeter with the values entered. Manual weather remains static until it is changed again.