Reading METAR and TAF: aviation weather decoded for plane spotters

EDDF 151050Z 24012G24KT 210V280 9999 FEW030 SCT045 16/08 Q1012 NOSIG – at first glance, that looks like a tangle of letters. For pilots it is the most important weather line before every approach, and for you as a spotter it contains almost everything that decides between a good day and a wasted one at the fence: which runway is in use, whether haze will soften your telephoto shots, whether the sun will come out and whether a thunderstorm is threatening. This guide shows you how to read METAR and TAF – group by group, with examples and the translation into spotter decisions.

METAR and TAF: the short answer

The METAR (Meteorological Aerodrome Report) is a standardized weather observation for a single airport. At German commercial airports it is usually issued every 30 minutes, at 20 and 50 minutes past the hour. If the weather changes significantly in between, a special report with the abbreviation SPECI may follow. The TAF (Terminal Aerodrome Forecast) is the matching forecast: it describes how wind, visibility, weather and clouds will develop over the next hours – depending on the airport for 9, 24 or, at large airfields, up to 30 hours.

Both formats follow international rules from ICAO and the World Meteorological Organization. That is the big advantage: once you understand the scheme, you read reports from Frankfurt, Zurich or Los Angeles equally well. There are small national deviations – in the US, for example, visibility is given in miles – but the structure stays the same.

The structure of a METAR, group by group

A METAR always follows the same order. Let us take the sample line from the beginning, a made-up but typical autumn day at Frankfurt Airport:

METAR EDDF 151050Z 24012G24KT 210V280 9999 FEW030 SCT045 16/08 Q1012 NOSIG

Group	Meaning	What you read from it as a spotter
EDDF	ICAO code of the airport	Frankfurt am Main – the four-letter codes are explained in the guide to IATA and ICAO codes
151050Z	Day 15, 10:50 UTC	12:50 p.m. German time in summer time
24012G24KT	Wind from 240°, 12 knots, gusts up to 24 knots	westerly pattern, operations probably toward 25; gusty approaches
210V280	Wind direction varies between 210° and 280°	crosswind component changes, exciting for landings
9999	Visibility 10 kilometers or more	clear air, even long focal lengths work
FEW030 SCT045	1–2 eighths at 3,000 ft, 3–4 eighths at 4,500 ft	mostly sun, occasional cloud shadows
16/08	Temperature 16 °C, dew point 8 °C	large spread, no fog risk
Q1012	Air pressure QNH 1012 hectopascals	a side issue for spotters
NOSIG	no significant change in the next two hours	the plan for the afternoon is set

Wind: the most important value for spotters

The wind group consists of three digits for the direction the wind comes from and two or three digits for the speed, usually in knots (KT). A G marks gusts, which are generally only reported if they are at least 10 knots above the mean wind. VRB stands for a variable, changing direction, usually in light wind, and 00000KT for calm.

Why this matters so much: aircraft take off and land into the wind. From the wind direction you can therefore work out which runway is used in which direction – and thus at which runway end and at which spot you are best placed. The runway number corresponds to the magnetic heading divided by ten, while the wind direction in the METAR is referenced to true north. In central Europe the two are only a few degrees apart, which makes no difference for choosing a spot. Details on runway numbers are in the article Airport runways and their designations, and the logic behind wind and runway choice is in the guide Understanding the runway direction in use.

An example: Munich Airport has two parallel east–west runways, 08/26. If the METAR reports 07008KT, takeoffs and landings are usually toward the east; with 26015KT, operations turn to the west. At the Munich Airport visitors’ hill, that means whether the aircraft roll toward you or away from you.

Visibility, RVR and weather phenomena

Visibility is given as a four-digit number in meters. 9999 means 10 kilometers or more, 0000 less than 50 meters. If visibility drops significantly, additional groups appear such as R25L/0600U: the runway visual range for runway 25L, here 600 meters with an improving trend (U = up, D = down, N = no change). If you see RVR values in the METAR, that is a clear sign of fog operations – how aircraft still land then is explained in the article on the ILS approach.

Then come the weather phenomena in a fixed pattern: intensity, descriptor, phenomenon.

Code	Meaning	Spotter’s take
- / +	light / heavy (no sign: moderate)	+RA means heavy rain
RA, DZ, SN	rain, drizzle, snow	spray and reflection subjects, pack camera protection
SH	showers	changeable light, often a dramatic sky
TS	thunderstorm	safety risk – end the session
FZ	freezing	slippery paths, de-icing on the apron
BR	mist, visibility 1 to 5 km	soft, low-contrast telephoto shots
FG	fog, visibility under 1 km	aircraft visible only shortly before touchdown
HZ	haze	flat light at long distance
VC	in the vicinity, not directly at the airfield	VCSH: showers nearby
RE	recent	RETS: a thunderstorm has just passed through

Clouds and CAVOK

Cloud cover is given in eighths: FEW 1–2, SCT 3–4, BKN 5–7, OVC 8 eighths. The three digits after it are the base in hundreds of feet above ground. If a CB (cumulonimbus) or TCU (towering cumulus) is attached to a group, shower or thunderstorm clouds are around. VV with a number stands for vertical visibility: the sky can no longer be seen, typical in dense fog. NSC means no significant cloud.

CAVOK, finally, is the code you hope for as a spotter. It replaces visibility, weather and clouds when there are simultaneously at least 10 kilometers of visibility, no clouds below 5,000 feet (or the minimum sector altitude, if that is higher), no CB or TCU and no significant weather. CAVOK does not automatically mean cloudless, though – high-altitude veil clouds can still dim the light.

Temperature, dew point, air pressure and trend

16/08 stands for 16 °C air temperature and an 8 °C dew point. You recognize negative values by the M, such as 02/M01. For spotters, the difference between the two values is interesting: the smaller it is, the closer the air is to saturation. If temperature and dew point are only one to two degrees apart – especially on clear, calm autumn and winter nights – the probability of haze and fog rises. Moist air also brings subjects, though: condensation over the wings or at the wingtips is seen more often on such days.

Q1012 is the air pressure reduced to sea level, in hectopascals (QNH). At the end comes the trend for the next two hours: NOSIG means no significant change, BECMG announces a lasting change, TEMPO temporary fluctuations. Between air pressure and trend there may be additional groups, such as RE for recent weather or WS for wind shear on a particular runway – a hint of bumpy approaches.

You can quickly gauge how large the gap between temperature and dew point is right now here:

Reading the TAF: the forecast for your spotting day

The TAF starts similarly to the METAR but contains a validity period. Here too, a made-up but realistic example, for Munich:

TAF EDDM 151100Z 1512/1618 07008KT CAVOK BECMG 1520/1522 VRB03KT TEMPO 1603/1608 0800 FG BKN002 BECMG 1610/1612 25015KT 9999 SCT030 PROB30 TEMPO 1614/1618 TSRA BKN025CB

• 151100Z – issued on the 15th at 11:00 UTC.
• 1512/1618 – valid from the 15th at 12 UTC until the 16th at 18 UTC, so 30 hours.
• 07008KT CAVOK – at first light easterly wind and the best weather: operations toward 08.
• BECMG 1520/1522 VRB03KT – in the evening the wind dies down.
• TEMPO 1603/1608 0800 FG BKN002 – in the second half of the night and early morning, temporary fog with 800 meters of visibility and a low cloud base.
• BECMG 1610/1612 25015KT 9999 SCT030 – late in the morning the wind shifts to the west: a change of runway direction to 26 is likely.
• PROB30 TEMPO 1614/1618 TSRA BKN025CB – in the afternoon a 30 percent probability of temporary thunderstorms with rain.

The change groups are the real added value of the TAF:

Code	Meaning	Consequence for your planning
FM	from an exact time (e.g. FM161300) a completely new condition applies	a clear break – often a weather or wind change
BECMG	a lasting change takes place during the stated period	afterward the new value applies, e.g. a new runway direction
TEMPO	temporary fluctuations, each under an hour and together under half the period	showers or fog patches pass through, plan for breaks
PROB30 / PROB40	probability of 30 or 40 percent	possible but not certain – have a fallback plan ready
AMD / COR	amended or corrected forecast	the situation has changed, read it again

This sample TAF yields a clear plan: the morning starts with fog risk, around midday the runway direction changes, and in the afternoon a thunderstorm may end the session. If you read it this way the evening before, you know which runway end to head for – and when it is not worth it.

From weather code to spot decision

With a little practice, reading becomes routine. This order has proven itself:

Typical weather patterns and what they mean for spotters

Strong, gusty crosswind, by the way, is no reason to stay home – quite the opposite. If the wind blows well across the runway, such as 21015G28KT with runway 25, you see approaches with the fuselage angled sideways, which are especially popular in the community. At the same time, the likelihood of go-arounds rises. How far apart aircraft have to keep is described in the article on Wake turbulence and separation.

Where to find METAR and TAF

METAR and TAF are made for aviation but are freely available in many places. The US weather service provides reports for airports worldwide at aviationweather.gov; you simply enter the ICAO code – EDDF for Frankfurt, EDDM for Munich, LSZH for Zurich Airport. Many weather and flight planning apps additionally show the raw report in plain language. Learn to read the original anyway: plain-language translations like to abbreviate, and TEMPO and PROB groups in particular get lost in the process.

If you want to link the weather with radio traffic: many airports also broadcast the current weather as an automatic announcement for pilots (ATIS). What applies legally when listening in is summarized in the article Listening to aviation radio: the legal situation.

What to keep in mind

• A METAR is a snapshot. It describes the time of observation. Between two reports, the situation can change – so pay attention to the timestamp.
• The runway direction in use does not follow only the wind. With light wind, noise abatement rules, construction work or operating requirements decide which direction is used.
• Cloud heights are given above ground. BKN008 means 800 feet above the airport – low enough that approaches emerge from the cloud only late.
• Gusts change your photo planning. With G groups, telephoto lens and tripod shake; a shorter shutter speed helps, more under camera settings.
• Thunderstorms take priority. If TS or CB appear in the report and you hear thunder, leave open hills and metal fences. Tips for dealing with rain, fog and clouds are in the guide Plane spotting in bad weather.

Conclusion

METAR and TAF only seem cryptic until you know the fixed order: airport, time, wind, visibility, weather, clouds, temperature, pressure, trend. For plane spotters, three things matter most – wind direction for the runway direction in use, visibility and haze for image sharpness, and the clouds along with thunderstorm indications for light and safety. With the TAF the evening before and the METAR before you leave, you will stand at the right runway end much more often. If you are just starting out, the guide Plane spotting for beginners helps too.