Decoding the METAR and the coded line of weather that is already happening over the field

A METAR is an aviation routine weather report—an actual observation of conditions at an airport at a specific moment, usually generated automatically once per hour. It is not a forecast; it is a snapshot of the truth on the ground as of a few minutes ago. If you can read one out loud like a plain-English sentence, you can turn a string of cryptic characters into a sound go/no-go decision before you ever climb into the airplane.

What Is a METAR and Why Does It Matter?

The word that defines a METAR is observation. It tells you what was actually happening at the field, not what someone predicts will happen later. Most reports are generated automatically once an hour, with special updates issued when conditions change quickly.

This is why the METAR is your anchor. Pilots tend to rush straight to the TAF (the forecast) because everyone cares about the future. But the METAR tells you where reality is right now. If the current conditions already disagree with what the forecast promised, that’s your signal the forecast is in trouble. The observation always wins the argument—the atmosphere doesn’t read the forecast.

How Do You Read a METAR Line by Line?

Here is a sample report for a home-base field. It looks like keyboard noise at first, so we’ll take it apart one piece at a time:

KXXX 221753Z AUTO 21015G25KT 10SM FEW035 BKN120 19/10 A2992 RMK…

The Station Identifier

The report opens with a four-letter station code. In the continental United States, that code starts with the letter K, which is simply the regional prefix for the lower 48. A field charted with three letters gets a K added to the front in the METAR. Learn your home airport’s identifier until it’s as familiar as your phone number.

The Date and Time (Zulu)

Next comes six digits followed by Z for Zulu. The first two digits are the day of the month—here, the 22nd. The next four are the time in Zulu (Coordinated Universal Time), not local time. Aviation runs on one global clock so nobody has to do time-zone math while flying.

So 221753Z means the observation was taken at 1753 Zulu on the 22nd. On the West Coast in summer you’d subtract seven hours, landing at about 10:53 a.m. local. Always check whether the weather you’re reading is fresh or stale—an old timestamp is a warning sign by itself.

AUTO — The Automated Station Flag

The word AUTO means the observation came from automated equipment rather than a human observer. Most fields are automated today. It’s worth noting because automated stations have blind spots: they look straight up, can miss a cloud layer off to the side, and aren’t great at distinguishing certain types of precipitation. Trust the report, but keep your own eyes working.

The Wind

This is the part most pilots care about: 21015G25KT. The first three digits are the direction the wind is coming from, in degrees. Here’s the trap—wind direction in a written METAR is referenced to true north, while ATIS, tower transmissions, and runway numbers are referenced to magnetic north. For planning off the printed report, it’s true; from the ATIS or tower, it’s magnetic.

So 210 means the wind is from the southwest, 15 means 15 knots sustained, and G25 means it’s gusting to 25. That 10-knot gust spread should make you sit up. Gusty wind isn’t just stronger wind—it’s unsteady wind that tests your crosswind technique and airspeed control all the way down final. On a north–south runway, a southwest wind gusting like this hands you the single most important go/no-go number of the morning in just nine characters.

The Visibility

After the wind comes visibility: 10SM, or 10 statute miles. In the U.S., METAR visibility is given in statute miles, and 10 is the top of the scale—it means 10 miles or better, wide open. When that number drops to 3, or 1, or fractions like ½, you’re looking at a day that may be legal for instrument flight but is closing the door on visual flight. Visibility is one half of your basic VFR weather minimums.

The Sky Condition and Ceiling

Cloud cover uses a short code measuring how much of the sky is covered, divided into eighths (octas). You don’t need to recite octas on the checkride, but you do need the ladder:

• CLR — clear
• FEW — a little
• SCT (scattered) — up to about half
• BKN (broken) — more than half, with gaps
• OVC (overcast) — fully closed lid

The critical concept is the ceiling: by definition, the lowest layer reported broken or overcast. Few and scattered layers don’t count, because you can still see up through the gaps.

In our example, FEW035 BKN120 means a few clouds at 3,500 feet and a broken layer at 12,000 feet. The few layer isn’t a ceiling; the broken layer is. So our effective ceiling is 12,000 feet—a beautiful VFR day.

Watch how fast that flips. If the report said BKN012 instead, your ceiling drops from 12,000 feet to 1,200 feet, and you’re suddenly at marginal VFR at best—possibly not legal to launch visually at all. One decimal place of attention is the whole game.

One more note: cloud altitudes are reported in hundreds of feet above ground level (AGL), above the airport elevation—not above sea level. 035 means 3,500 feet above the field.

Temperature and Dewpoint

Next, temperature and dewpoint separated by a slash: 19/10. That’s 19°C air temperature and 10°C dewpoint—always Celsius in a METAR. The dewpoint matters for two safety reasons.

First, the spread between temperature and dewpoint tells you how close the air is to saturating into cloud or fog. When the two get within a couple of degrees, fog or low cloud becomes very likely, especially as the day cools. Nineteen over ten is a comfortable 9-degree spread. But 11/10—one degree apart—means a clear morning could be socked in fog within the hour. The dewpoint is your early warning for weather the report hasn’t caught yet.

Second, temperature feeds directly into density altitude and aircraft performance. A hot day at a high field is a different airplane than the one in the book, and the METAR temperature is the first ingredient in that calculation.

The Altimeter Setting

Then comes the letter A followed by four digits: A2992. That’s the barometric pressure, 29.92 inches of mercury, which you dial into the Kollsman window so the altimeter tells you the truth about your altitude. Standard pressure is 29.92, so this morning is right at standard. On a stormy low-pressure day you might see 29.50 or lower—and forgetting to set it makes your altimeter read high, telling you that you have more room beneath you than you really do. That’s not paperwork; that’s terrain clearance.

The Remarks Section

Finally, many reports end with a remarks (RMK) section, sometimes plain language, sometimes more code. This is the color commentary—a thunderstorm moving off to the east, the peak wind, a rapid pressure change. Don’t skip the remarks. That’s often where the human-flavored warning lives.

Putting It All Together: Reading the Whole METAR

Now we can read the entire report as a sentence:

Our home field, observed on the 22nd at 1753 Zulu by an automated station. Wind from the southwest at 15, gusting 25. Visibility 10 miles or better. A few clouds at 3,500, ceiling broken at 12,000. Temperature 19, dewpoint 10—a comfortable spread. Altimeter 29.92, right at standard.

In plain English: a gorgeous, clear, breezy day. The only item on the worry list is that gusty crosswind—and now you know to brief it before you climb in. You took a line that looked like keyboard noise and turned it into a flying decision.

How Do You Get Fast at Reading METARs?

The only way to build this skill is reps. Pull up the METAR for your home field every single day, even when you’re not flying. Read it out loud in the car. Within a couple of weeks it stops being code and starts being a sentence.

Three practical habits go with it. First, the METAR is the now—pair it with the forecast for later and the winds aloft for up there. No single product is the whole story. Second, respect the timestamp; a beautiful METAR from two hours ago in fast-moving weather isn’t describing the airplane you’re about to fly. Third, when the current observation contradicts the forecast, believe the observation.

This information comes from the National Weather Service and the Aviation Weather Center, and the standards behind it live in the FAA’s Aviation Weather Handbook, which is free and worth a slow read.

Key Takeaways

• A METAR is an observation, not a forecast—a snapshot of actual conditions at the field, usually updated hourly. When it disagrees with the forecast, believe the METAR.
• Read it in order: station, Zulu date/time, AUTO flag, wind, visibility, sky/ceiling, temp/dewpoint, altimeter, remarks.
• A ceiling is the lowest broken (BKN) or overcast (OVC) layer; few and scattered layers don’t count. Cloud heights are AGL in hundreds of feet.
• Written METAR wind is referenced to true north; ATIS and tower wind are referenced to magnetic north.
• A small temperature–dewpoint spread warns of fog, and always reset your altimeter—standard pressure is 29.92 inHg.