How do I read a METAR for flight simulation?

To read a METAR for flight simulation, work through it in order: station, time, wind, visibility, weather, cloud, temperature/dew point, and pressure. Once you know what each group means, you can quickly choose the right runway, set the altimeter, judge ceilings and visibility, and decide whether the weather suits VFR or IFR.

What is a METAR in flight simulation?

A METAR is a coded weather report for an aerodrome. In simming, it is the quickest way to understand the conditions you are about to fly in, whether you are matching live weather, building your own weather preset, or checking if an approach is realistic.

We read METARs in the same order every time because the format is designed to be scanned left to right. Once that habit clicks, even a messy-looking line of code becomes quite readable.

What does each part of a METAR mean?

Here is a simple example:

EGLL 121350Z 24012KT 9999 SCT020 BKN035 18/12 Q1016 NOSIG

This decodes as: London Heathrow, observed on the 12th at 13:50 UTC, wind 240 degrees at 12 knots, visibility 10 km or more, scattered cloud at 2,000 ft, broken cloud at 3,500 ft, temperature 18C, dew point 12C, pressure 1016 hPa, and no significant change expected in the short term.

1. Station identifier tells you which airport the report is for. EGLL is Heathrow, KJFK is Kennedy, and so on. The four-letter ICAO code matters because nearby airports can have very different weather.
2. Observation time appears as day and time in UTC, ending with Z. 121350Z means the 12th day of the month at 13:50 Zulu. In a sim, this helps you decide whether the report is current enough to trust.
3. Wind is given as direction and speed. 24012KT means wind from 240 degrees true at 12 knots. If you see gusts, they appear like 24012G22KT, meaning gusting to 22 knots.
4. Visibility comes next. Outside North America it is often in metres, so 9999 usually means 10 km or more. In US-style reports you may see statute miles, such as 10SM or 3/4SM.
5. Present weather uses short codes like RA for rain, SN for snow, FG for fog, and TS for thunderstorm. A minus sign means light, a plus sign means heavy. So -RA is light rain and +TSRA is heavy thunderstorm rain.
6. Cloud layers show sky cover and height above the aerodrome in hundreds of feet. SCT020 means scattered cloud at 2,000 ft, and BKN035 means broken cloud at 3,500 ft. Broken and overcast layers are the important ones for ceilings.
7. Temperature and dew point appear as two numbers separated by a slash. 18/12 means temperature 18C, dew point 12C. If they are close together, expect high humidity and a greater chance of mist, fog, or low cloud.
8. Pressure is the altimeter setting. Q1016 means QNH 1016 hPa. In some regions, especially the US, you may see A2992, which means 29.92 inches of mercury.
9. Trend or remarks may appear at the end. NOSIG means no significant change expected soon. Some reports include extra detail in remarks, but many sims do not use every remark field.

METAR example decoded step by step

Let us take a slightly busier example:

KDEN 121653Z 01018G28KT 2SM -SN BR BKN012 OVC025 M03/M05 A2985

Read it like this:

• KDEN = Denver International
• 121653Z = observed on the 12th at 16:53 UTC
• 01018G28KT = wind from 010 degrees at 18 knots, gusting 28
• 2SM = 2 statute miles visibility
• -SN = light snow
• BR = mist
• BKN012 = broken cloud at 1,200 ft
• OVC025 = overcast cloud at 2,500 ft
• M03/M05 = temperature minus 3C, dew point minus 5C
• A2985 = altimeter 29.85 inHg

From a sim pilot's point of view, that tells us a lot straight away: gusty winds, reduced visibility, snow, a low ceiling, and temperatures cold enough for icing concerns. That is already enough to influence aircraft choice, runway selection, and whether a VFR flight is sensible at all.

Common METAR codes sim pilots should know

How do I use a METAR in a flight simulator?

Reading the code is only half of it. The useful part is turning the report into a flying decision.

Runway selection

Use the wind group first. If the METAR shows 24012KT, a runway roughly aligned with 24 will usually give the best headwind component. If the wind is strong or gusty, crosswind limits become a real issue, especially in lighter aircraft.

Altimeter setting

Set the pressure exactly as published. In a sim, just as in real flying, the wrong QNH or altimeter setting can leave you hundreds of feet off, which matters a lot on approach, in hilly terrain, or when trying to match charted altitudes.

VFR or IFR judgement

Look at visibility and cloud base together. Good visibility with a broken layer at 800 ft is still poor VFR weather for most operations. A broken or overcast layer is the ceiling; scattered cloud is not.

Icing, fog and low cloud risk

If temperature and dew point are close, the air is moist. If the temperature is near or below freezing and there is cloud or precipitation, think about icing. Many sims model this unevenly, but the METAR still tells you what conditions you are trying to reproduce.

METAR codes that often confuse beginners

What does CAVOK mean?

CAVOK means visibility is good, there is no significant weather, and no cloud below an important reporting threshold. In practical sim terms, it usually means an easy-weather day with no low cloud to worry about.

What does AUTO mean?

AUTO means the report was generated automatically rather than fully observed by a human. That can matter because automated stations may miss some cloud detail or certain weather phenomena that a person would report more clearly.

What does NOSIG mean?

NOSIG means no significant change expected in the near term. It is helpful, but not a promise. Sim weather engines and real weather alike can still evolve faster than the report suggests.

What if the wind is variable?

You may see VRB03KT for light variable wind, or a range such as 180V250, meaning the wind direction is varying between 180 and 250 degrees. That usually matters most when choosing a runway and anticipating changes on final.

METAR versus TAF: which one should you use?

A METAR is an observation of current conditions. A TAF is a forecast for future conditions. For flight simulation, we use the METAR to set what the airport is like now, and the forecast to judge what may happen during the flight or on arrival.

If your sim uses live weather, remember that it may blend METAR data with broader model data. That is why what you see out of the window does not always match the METAR perfectly, especially away from the airfield or when the weather is changing quickly.

A quick way to read any METAR

If you want a repeatable routine, use this order every time:

1. Airport — which field is this for?
2. Time — is the report recent?
3. Wind — which runway and how demanding will handling be?
4. Visibility — VFR-friendly or not?
5. Weather — rain, snow, fog, thunderstorm?
6. Cloud — where is the ceiling?
7. Temperature/dew point — moisture, fog and icing clues
8. Pressure — set the altimeter correctly

That is enough to decode most METARs you will meet in flight simulation without getting bogged down in every obscure remark field.

Why your simulator may not match the METAR exactly

This catches plenty of simmers out. A simulator may update weather on a delay, smooth abrupt changes, or use modelled weather between reporting stations. Some sims also simplify visibility layers, cloud types, gust behaviour, or precipitation intensity.

So if the METAR says broken cloud at 2,000 ft and your sim shows something a little different, that does not always mean the weather is wrong. It may just be a limitation of how the simulator translates the report into a 3D atmosphere.

Bottom line

To read a METAR for flight simulation, decode it in sequence and focus on the parts that affect the flight: wind, visibility, cloud base, temperature, and pressure. Once you can spot runway wind, ceiling and QNH at a glance, you are reading METARs well enough to plan and fly realistically.