The METAR, Decoding the Hourly Weather Observation Line by Line, and Why the Remarks Section Hides the Story Nobody Reads

A METAR is an aviation routine weather report: an hour-by-hour observation of the actual conditions at an airport, not a forecast. It always follows the same order - station, time, wind, visibility, clouds, temperature/dewpoint, altimeter, and remarks - so once you know the sequence, you’re reading a sentence, not a code. The most valuable part is the remarks section (RMK), where the observation stops being a snapshot and starts telling you whether the weather is getting better or worse.

What Is a METAR and How Is It Different From a TAF?

A METAR is an observation - it tells you what already happened and what is happening right now at an airport. It’s issued once an hour, usually somewhere in the 50-something-minute range, just before the top of the hour.

Contrast that with the Terminal Aerodrome Forecast (TAF), which tells you what someone expects will happen. The observation is the truth on the ground. The forecast is an educated opinion.

When the two disagree - and they will - believe the observation for right now and respect the forecast for later. The METAR has no reason to lie to you about current conditions.

If the code looks intimidating at first, that’s normal. A METAR is always in the same order, every time, everywhere in the world. Once you learn the order, it stops being a secret language.

How Do You Read a METAR Line by Line?

Let’s decode a real, typical example from start to finish:

METAR KDAB 141453Z 24015G22KT 10SM FEW030 BKN250 27/17 A2992 RMK…

Here’s what each field is telling you.

The Report Type: METAR or SPECI

The first word tells you what kind of report this is. METAR means the routine hourly report. If you instead see SPECI, that’s a special report - issued when something changes fast enough that the station couldn’t wait for the top of the hour.

A SPECI means the visibility dropped, a thunderstorm moved in, or the wind shifted hard. If you see SPECI, your antenna should go up. Something changed, and it changed enough to demand an immediate report.

The Station Identifier

Next comes the station identifier. In our example, KDAB is Daytona Beach, Florida. In the lower 48, identifiers start with K followed by three more letters - the same identifiers you already use when filing flight plans. This field just tells you which airport is talking.

The Date and Time (Always in Zulu)

Our example reads 141453Z. The first two digits, 14, are the day of the month - the 14th. The next four digits are the time: 1453, meaning fifty-three minutes past the 1400 hour.

The Z stands for Zulu time (Coordinated Universal Time). Every METAR on Earth is stamped in Zulu so a pilot in Tokyo and a pilot in Atlanta read the same clock. You convert to local time yourself.

Always look at the time stamp first. If a METAR is three hours old, it’s a museum piece. If the airport reports hourly and it’s now 40 minutes past, your information is 40 minutes stale - and that matters when weather is moving.

The Wind

Our example: 24015G22KT. The first three digits are always the direction the wind is coming from, in degrees, referenced to true north - not magnetic.

This is a trap that bites people. The coded METAR wind is true north. The wind the tower gives you on the radio and the ATIS is magnetic, because it’s lining you up with a runway. Keep those separate.

So 240 means the wind is from 240 degrees (out of the southwest), 15 is the speed in knots, and G22 means gusting to 22 knots. That 7-knot gust spread is where you start rehearsing the landing before you ever leave the ground.

Two more wind notes:

• VRB means the direction is variable and bouncing around.
• A direction followed by a V and two more directions (e.g., 180V240) means the wind is varying across that range. On a gusty day near your crosswind limit, that variability is the whole story.

The Visibility

Our example: 10SM. In the United States, METAR visibility is in statute miles, and 10 is the highest it usually reports.

When the number drops, lean in. Three miles, one mile, a half mile (written as a fraction) - the moment visibility falls below three miles and ceilings come down, you’re staring at the line between VFR and IFR. For a VFR-only pilot, this single field can end your day before it starts.

The Cloud Layers

Our example: FEW030 BKN250. Cloud layers are reported by how much of the sky they cover, in eighths, and by height above ground level in hundreds of feet. The four coverage words are few, scattered, broken, and overcast.

Few and scattered are legally not a ceiling - the sky is more open than not. Broken and overcast are a ceiling.

So FEW030 is a few puffy clouds at 3,000 feet, and BKN250 is high cirrus at 25,000 feet - nothing that affects a light airplane. A blue-sky day. But change one word: BKN008 would be an 800-foot broken ceiling, and suddenly it’s a completely different flight.

On your checkride, the examiner isn’t testing whether you can recite numbers. They want you to read the ceiling and visibility together and say out loud whether it’s a VFR day, a marginal VFR day, or a hard no.

The Temperature and Dewpoint

Our example: 27/17. Temperature comes first, then dewpoint, both in degrees Celsius, separated by a slash - so 27 degrees over 17 degrees. An M in front of a number means minus (below zero).

The gap between the two is the spread, and it tells you how close the air is to being saturated. When the spread closes to a couple of degrees or less, you get fog and low clouds.

On an early-morning flight, a temperature of 10 and a dewpoint of 9 - one degree of spread - should make you think fog. It may be clear now, but a little cooling at dawn will tip it over. That spread is a fog forecast hidden inside an observation.

The temperature also drives density altitude, which determines whether your airplane climbs like it should or wallows off the runway on a hot day. A 27-degree afternoon at a high-elevation airport is a very different takeoff than a standard day.

The Altimeter Setting

Our example: A2992. The A is followed by four digits: 29.92 inches of mercury. You dial that into your Kollsman window so your altimeter reads true field elevation. Set the wrong altimeter and every altitude you fly is a lie.

Why Is the Remarks Section the Part That Matters Most?

Everything above - wind, visibility, clouds, temperature, altimeter - is the body of the METAR. Most pilots read to the altimeter and stop. Don’t stop.

After the altimeter comes RMK, the remarks, and this is where the observation quietly tells you things the coded body cannot.

Remarks tell you how the observation was made. You might see:

• AO2 - an automated station with a precipitation discriminator; it knows rain from snow.
• AO1 - automated but without a precipitation discriminator.

That small detail tells you whether a human or a machine is watching. Machines have blind spots - an automated station can miss a thunderstorm sitting off to the side because it only looks straight up.

Remarks carry the timing and trend of significant weather. You’ll find codes for when a thunderstorm began or ended, when rain started, and when the wind shifted. A WSHFT (wind shift) note tells you a front just came through and gives you the time. The body shows the snapshot; the remarks show whether things are getting better or worse.

Remarks carry pressure information - sea level pressure and pressure tendency, the note showing whether the barometer has been rising or falling over the last three hours. Falling pressure often means deteriorating weather is on the way. That’s an observation handing you a free clue about the future.

Remarks flag distant hazards. You might see a note like lightning distant northwest (LTG DSNT NW). The coded body could still read 10 miles and clear, while the remarks warn of a storm that hasn’t reached the field yet but is marching toward it. Read only to the altimeter and you never see it coming.

How Should You Actually Read a METAR Before a Flight?

Here’s a real scenario. Early-morning VFR cross-country. You pull the METAR for your destination and the body looks workable: visibility three miles, a few clouds - marginal but flyable.

Then you read the remarks. Temperature and dewpoint are one degree apart, the pressure is falling, and there’s a note that visibility was lower ten minutes ago in mist. Now the picture changes. That three miles isn’t stable - it’s on its way down, and the fog will likely be on the field about the time you’d arrive.

The body told you the snapshot. The remarks told you the movie.

Here’s the routine to build: read every field, in the same order, every time, until it becomes automatic:

1. Time - is this observation fresh?
2. Wind - direction (true), speed, gusts, variability.
3. Visibility - VFR, marginal, or IFR?
4. Sky - is there a ceiling?
5. Temperature and dewpoint - how tight is the spread?
6. Altimeter - set it correctly.
7. Remarks - how was it made, and which way is it trending?

The format and codes come straight from the Federal Aviation Administration and the National Weather Service, and you’ll find the full breakdown - including the deeper remarks - in the Aviation Weather Handbook if you want to go further.

Reading weather feels like a foreign language right up until the day it clicks. Nobody reads it fluently on day one, but every METAR you decode makes the next one faster.

Key Takeaways

• A METAR is an observation of current conditions, updated hourly; a TAF is a forecast. When they disagree, trust the observation for now and the forecast for later.
• METARs always follow the same order: station, time, wind, visibility, clouds, temperature/dewpoint, altimeter, remarks.
• Check the time stamp first - stale weather is dangerous when conditions are moving - and remember the coded wind is true north while tower and ATIS winds are magnetic.
• A tight temperature-dewpoint spread (a couple degrees or less) signals fog and low clouds, even on a currently clear day.
• Don’t stop at the altimeter. The remarks (RMK) reveal how the observation was made, distant lightning, wind shifts, and pressure trends - the story of whether the weather is improving or falling apart.