How to Decode a METAR Report

METAR reports are the backbone of aviation weather. Issued every hour (or more frequently when conditions change), they give pilots a snapshot of current weather at an airport. At first glance, a METAR looks like gibberish — but once you know the format, it becomes second nature.

Anatomy of a METAR

Let's break down a real example:

METAR KJFK 101856Z 31012G20KT 10SM FEW040 SCT250 22/11 A3012 RMK AO2

Report Type

METAR — Routine observation. You may also see SPECI, which is a special observation issued when conditions change significantly.

Station Identifier

KJFK — The ICAO code for the airport. In the US, these start with "K" followed by the FAA identifier.

Date and Time

101856Z — The 10th day of the month at 18:56 Zulu (UTC). All METARs use UTC to avoid confusion across time zones.

Wind

31012G20KT — Wind from 310 degrees at 12 knots, gusting to 20 knots. Calm wind shows as 00000KT. Variable winds below 6 knots may appear as VRB04KT.

Visibility

10SM — 10 statute miles. This is the maximum reported in US METARs. Internationally, visibility is in meters (e.g. 9999 means 10 km or more).

Sky Condition

FEW040 SCT250 — Few clouds at 4,000 feet AGL, scattered at 25,000 feet AGL. Coverage codes:

• SKC/CLR — Clear
• FEW — 1–2 oktas
• SCT — 3–4 oktas (scattered)
• BKN — 5–7 oktas (broken)
• OVC — 8 oktas (overcast)

Temperature and Dewpoint

22/11 — Temperature 22°C, dewpoint 11°C. When these converge, expect fog. Negative values use "M" prefix: M02/M05 means −2°C/−5°C.

Altimeter Setting

A3012 — 30.12 inHg. Internationally you'll see Q1013 for QNH in hectopascals.

Common Weather Codes

Intensity prefixes: − light, no prefix moderate, + heavy. So -TSRA is a light thunderstorm with rain.

Practice Makes Perfect

The best way to learn METARs is to decode one every day. Pull up your local airport's report and work through each field. Within a couple of weeks you'll read them as naturally as plain text.