How to read a METAR

A METAR is an observation — what the weather actually is at an airport right now, not what someone expects it to be. Once you can read one at a glance, it is the fastest weather picture in aviation.

Last updated August 2026

METARs are issued roughly hourly, usually just before the top of the hour, with a SPECI issued out of sequence when conditions change significantly. The format is deliberately terse and always in the same order, which is what makes it scannable once the order is familiar.

METAR is an international standard. The same abbreviations are used at every airport on Earth, so learning them once works everywhere — no translation, no regional dialect to relearn. The differences are in units rather than structure, and are covered below where they arise.

A complete example

Read left to right, that is: Seattle-Tacoma, observed on the 8th at 11:53 UTC, wind from 190° at 8 knots, visibility 10 statute miles, a few clouds at 800 feet and scattered at 20,000 feet, 14 °C with a dewpoint of 11 °C, altimeter 29.96, and an automated station reporting sea-level pressure 1014.6 hPa.

Field by field

Station and time

KSEA 081153Z — the ICAO identifier, then a six-digit group: day of month (08), hour and minute (11:53), and Z for Zulu (UTC). The day matters more than pilots expect: near the end of a month, an old report can look current if you only read the time.

Wind

19008KT — direction in degrees true, then speed in knots. Some variations:

• 19008G22KT — gusting to 22 knots.
• VRB04KT — variable direction, 4 knots. Common in light and calm conditions.
• 18012KT 150V210 — steady 180° at 12, but varying between 150° and 210°.
• 00000KT — calm.

Wind in a METAR is true, but the wind a tower or ATIS gives you for takeoff and landing is magnetic. In areas with large variation — much of Alaska, for instance — that difference is big enough to pick the wrong runway if you forget which one you are holding.

Visibility

10SM — statute miles. Fractions appear as 1/2SM or 2 1/2SM. M1/4SM means less than a quarter mile. Automated stations top out at 10 miles, so 10SM means "ten or more", not exactly ten.

Outside North America you will see metres instead, as a bare four-digit group: 0800 is 800 metres, and 9999 is the standard way of saying 10 km or more. You may also meet CAVOK — ceiling and visibility OK — which replaces the visibility, weather and cloud groups altogether when visibility is 10 km or more, there is no cloud below 5,000 feet or the highest minimum sector altitude, and no significant weather. It is common in Europe and rare in the United States.

You may also see runway visual range as R16L/1200FT or R06/P2000 — a measured value for a specific runway, which matters when the prevailing visibility and what you will actually see on final differ.

Weather phenomena

Between visibility and clouds you may see codes such as -RA (light rain), +SN (heavy snow), BR (mist), FG (fog), TSRA (thunderstorm with rain), VCTS (thunderstorm in the vicinity). Intensity prefixes are - light, no prefix moderate, + heavy.

Cloud layers

Each layer is a three-letter cover code plus a height in hundreds of feet above ground level:

So FEW008 is a few clouds at 800 feet AGL and SCT200 is scattered at 20,000 feet.

Only BKN, OVC and VV count as a ceiling. This is the single most consequential rule in the whole report. SCT004 is not a ceiling, so a field reporting scattered at 400 feet with good visibility is legally VFR — even though you may see very little forward once you are in it. Conversely BKN004 is a 400-foot ceiling and puts the field solidly in IFR.

Temperature and dewpoint

14/11 — degrees Celsius, with M for negative values, so M03/M07 is −3 °C and −7 °C. The gap between the two is the number to watch. A close spread means the air is near saturation: fog and low stratus become likely, especially with light wind and clear skies overnight. A spread of 2 °C or less around dawn deserves real attention.

The spread is also your carburettor icing cue and, roughly, your cloud base: divide the spread in °C by 2.5 and multiply by 1,000 to estimate the base of convective cloud in feet AGL.

Altimeter

A2996 — inches of mercury with the decimal removed, so 29.96 inHg. Outside North America you will see Q1014 instead, which is hectopascals.

Remarks

Everything after RMK. Frequently useful entries include AO1/AO2 (automated station without/with a precipitation discriminator), SLP146 (sea-level pressure 1014.6 hPa), P0003 (0.03 inches of precipitation in the last hour), T01390106 (temperature and dewpoint to a tenth of a degree), and plain-language notes from a human observer such as TSB25 (thunderstorm began at 25 past).

The traps

An old report reads exactly like a current one

Nothing in the format shouts that an observation is three hours stale. Always check the day-and-time group against the current UTC time. Airports without 24-hour service simply stop reporting, and the last observation sits there looking valid.

AUTO stations cannot see everything

An AUTO report comes from instruments. They measure the sky directly overhead and struggle above about 12,000 feet, so a solid deck just off the field can go unreported. They also cannot distinguish some precipitation types. Treat automated observations at remote fields as one input, not the whole picture — and cross-check against nearby stations, the area forecast, and any PIREPs.

Ceilings are AGL, and the field may not be at sea level

A 1,000-foot ceiling at an airport with a 5,000-foot elevation is cloud at 6,000 feet MSL. Mixing the two is a classic way to plan an altitude straight into a layer.

Reading it in Flight Kneeboard

Search any airport and open Weather. The METAR is shown decoded, and you can tap any token in the raw text to see what that specific group means in place — useful when you hit a code you do not recognise mid-briefing. The History tab charts up to eight days of observations by wind, ceiling, visibility, flight category and more, which is how you spot that a field goes IFR every morning at first light and lifts by ten.

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