Paste a METAR or TAF to Decode, or type an airport code to get the weather.

Cover is measured in oktas (eighths of the sky): FEW is 1-2, SCT (scattered) is 3-4, BKN (broken) is 5-7, OVC (overcast) is 8. The lowest BKN or OVC layer is the ceiling. VV (vertical visibility) means the sky is obscured (fog or snow), and the ceiling is how far up you can see, e.g. VV002 = 200 ft.

A minus prefix means light (-RA, light rain), no prefix means moderate (RA), and a plus means heavy (+RA). VC means "in the vicinity" (within about 5-10 SM of the station but not at it).

US reports use statute miles (10SM). Most of the world uses meters: 9999 means 10 km or more, 0800 means 800 m. In TAFs, P6SM means "more than 6 statute miles". Fractions like 1¾SM appear when visibility is low.

First three digits are the true direction the wind is from, next two are speed in knots, G adds gusts: 18020G28KT is from 180° at 20 gusting 28. VRB03KT is variable at 3 kt; 00000KT is calm. A group like 170V230 shows the direction varying between 170° and 230°.

A-groups are inches of mercury, used in the US: A2992 = 29.92 inHg. Q-groups are hectopascals, used in most of the world: Q1013 ≈ 29.92 inHg. Setting the wrong unit is a classic international-flying gotcha.

AO1/AO2 describe the automated sensor suite. SLP088 is sea-level pressure (1008.8 hPa). T-groups give temperature to a tenth of a degree. PK WND is the peak wind since the last report; PRESRR/PRESFR flag pressure rising or falling rapidly; RAB25 means rain began at :25.

NOSIG means no significant change expected in the next two hours. NSW means significant weather has ended. BECMG forecasts a gradual change. Temperatures below zero are prefixed with M: M02/M05 is −2°C with a dewpoint of −5°C.

"Ceiling and visibility OK": visibility 10 km or more, no cloud below 5,000 ft (or the minimum sector altitude), no cumulonimbus, and no significant weather. Common in international reports; never used in the US.

The altimeter setting that makes your altimeter read field elevation on the ground. Q1013 is QNH in hectopascals. US A-groups serve the same purpose in inches of mercury.

How far you can see down a specific runway, measured by sensors: R27/0800 is 800 m looking down runway 27. Reported when visibility is poor; it drives takeoff and approach minimums.

A rapid change in wind speed or direction with height, most hazardous on approach and departure. TAFs use WS groups (e.g. WS020/18040KT); METAR remarks may flag LLWS. Treat any mention seriously.

An unscheduled METAR issued when conditions change significantly between routine reports (a thunderstorm arrives, a ceiling drops, visibility falls). Decode it exactly like a METAR.