How to Read a METAR and TAF: Pilot’s Complete Weather Guide

Every preflight starts with a weather briefing — and at the center of that briefing is a METAR. However, for many GA pilots, decoding one quickly and accurately takes more practice than it should. This guide walks you through how to read a METAR and TAF from start to finish, so you can extract what matters and make a confident go/no-go call before every flight.

What Is a METAR?

A METAR (Meteorological Aerodrome Report) is an official surface weather observation issued at airports worldwide, typically every hour on the hour. Specifically, it gives you a snapshot of conditions at a single location at a fixed point in time — wind, visibility, cloud layers, temperature, dewpoint, and altimeter setting. In the U.S., ASOS and AWOS stations also issue Special METARs (SPECIs) whenever conditions change significantly between hourly reports. Because METARs follow an internationally standardized format, a pilot trained on U.S. reports can decode one from any ICAO station around the world.

A TAF (Terminal Aerodrome Forecast), by contrast, is a forecast rather than an observation. However, both serve distinct purposes. Together, they give you a complete weather picture — what conditions exist right now and what’s expected over the next 24 to 30 hours.

Breaking Down Each Field

Let’s use a realistic example throughout this guide:

METAR KPHX 141753Z 24012KT 10SM FEW030 SCT080 BKN250 28/08 A2992 RMK AO2 SLP118 T02830083

Each group in that string represents a specific element. In fact, breaking it down field by field is the fastest way to internalize the format — and more importantly, the fastest way to extract what actually affects your flight.

Station Identifier and Observation Time

KPHX is the ICAO four-letter code for Phoenix Sky Harbor International Airport. In North America, all U.S. airports begin with “K” — so Los Angeles becomes KLAX, and Denver becomes KDEN. Canadian stations begin with “C”, and Mexican airports with “MM”. For cross-country planning, specifically note that rural airports without ASOS or AWOS stations won’t have their own METAR. In those cases, use the nearest reporting station as your reference and account for any terrain differences.

141753Z means the observation was taken on the 14th day of the month at 1753 Zulu (UTC). METARs always use Zulu time, not local time. Therefore, before preflight, convert to local time and confirm the report is current. Additionally, a METAR older than 90 minutes deserves extra scrutiny — especially when conditions appear to be changing rapidly.

METAR Wind Group

24012KT means winds from 240° at 12 knots. When gusts are present, a “G” separates the sustained and gust values — for example, 24012G22KT means 240° at 12 knots gusting to 22. Variable wind direction below 6 knots is reported as VRB, as in VRB04KT. Furthermore, completely calm conditions appear as 00000KT. Reported wind direction is magnetic in the U.S. Additionally, when wind direction varies significantly through a range, a variable group like 210V280 follows the primary wind entry to show the full spread.

Visibility and Weather Phenomena

10SM means 10 statute miles — the maximum reported value in U.S. METARs. Specifically, values below 10SM are expressed as fractions: 3SM, 1SM, ½SM, or M¼SM (less than one-quarter mile). In international METARs, visibility is often reported in meters rather than statute miles. Additionally, runway visual range (RVR) may follow the visibility group in low-visibility conditions — for example, R28R/2400FT means Runway 28 Right has an RVR of 2,400 feet.

Present weather codes appear between the visibility and sky condition groups when something is occurring at the station. In our example, no weather code appears — skies are clear of precipitation. However, when present, codes follow a structured format: intensity qualifier (-/+), descriptor (TS, SH, FZ, BL), and precipitation type (RA, SN, DZ). For example, -SHRA is light rain showers, +TSRA is heavy thunderstorms with rain, and FZRA is freezing rain.

Sky Condition and Ceiling

FEW030 SCT080 BKN250 describes three separate cloud layers. Each entry uses a three-letter coverage code followed by the layer height in hundreds of feet AGL. Therefore, FEW030 is a few clouds at 3,000 feet, SCT080 is scattered at 8,000, and BKN250 is broken at 25,000. Sky conditions are always reported in ascending order. For VFR pilots, the ceiling is defined by the lowest BKN or OVC layer — in this example, 25,000 feet broken creates no practical VFR restriction. However, if that layer dropped to BKN015, your options would narrow quickly.

Temperature, Dewpoint, and Altimeter Setting

28/08 means temperature 28°C and dewpoint 08°C. Both values are in Celsius, and a leading “M” indicates a minus reading — M05 means -5°C. The spread between temperature and dewpoint is a useful indicator of moisture content and fog risk. Specifically, when the spread narrows to 2-3°C, fog or low clouds are likely forming or imminent. Temperature is also essential for density altitude calculations — high temperatures at elevation airports significantly reduce aircraft performance margins.

A2992 is the altimeter setting in inches of mercury. In international METARs, the “Q” group replaces the “A” and reports in hectopascals — Q1013 is roughly equivalent to 29.92 inHg. Always set your altimeter before departure. Furthermore, on cross-countries, update it with each new ATIS or AWOS check to keep your indicated altitude accurate throughout the flight.

METAR Remarks Section

Everything after RMK provides supplementary data beyond the coded fields. In our example, AO2 means the station has a precipitation discriminator and can distinguish rain from snow. Additionally, SLP118 is the sea-level pressure in millibars (1011.8 mb), which is useful for tracking pressure trends across a briefing. The T-group (T02830083) gives precise temperature and dewpoint readings to the nearest tenth degree. Remarks also include lightning direction, variable ceiling data, and significant weather details that don’t fit neatly into the standard coded groups. As a result, always scan the RMK section — it often contains information that directly affects your flight.

Decoding Weather Phenomena and Sky Condition Codes

Present weather codes follow a logical structure once you know the building blocks. Specifically, the table below covers the most common codes you’ll encounter during GA preflight:

Descriptors combine with precipitation types to build specific codes. For instance, FZRA is freezing rain, BLSN is blowing snow, and TSRA is thunderstorms with rain. The VC qualifier specifically indicates phenomena occurring within 5 to 10 miles of the station but not at the station itself — VCSH means showers in the vicinity, not directly overhead. Additionally, combined codes like -RASN indicate light rain and snow occurring simultaneously.

Sky Condition Codes and VFR Ceilings

Sky condition codes use four coverage designators based on eighths of the sky dome covered:

For VFR pilots, the ceiling is the lowest BKN or OVC layer. Therefore, SCT and FEW layers below your intended cruise altitude don’t establish a formal ceiling — however, they still affect your ability to maintain cloud clearance. In Class E airspace below 10,000 feet MSL, you need 500 feet below, 1,000 feet above, and 2,000 feet horizontal from clouds, regardless of whether a formal ceiling is reported.

How a TAF Differs from a METAR

A TAF is a 24- to 30-hour aerodrome forecast issued four times daily by the National Weather Service. While a METAR gives you a real-time observation, a TAF instead projects expected conditions over the next day. However, TAFs are only issued for airports with instrument approaches and sufficient flight activity — many small GA airports won’t have one. In those cases, use the nearest TAF airport combined with current pilot reports (PIREPs) to complete your weather picture.

The TAF format shares several codes with the METAR — specifically, the same wind, visibility, weather phenomena, and sky condition groups apply directly. Specifically, the key difference lies in how conditions change over time. TAFs use change group codes to describe transitions throughout the forecast period.

Reading a TAF: Change Groups and Forecasts

Here’s a sample TAF:

TAF KPHX 141120Z 1412/1512 24012KT P6SM SKC
     FM1800 26015G25KT P6SM SCT040
     TEMPO 2000/2200 8SM TSRA BKN025CB
     BECMG 2200/2300 VRB04KT P6SM SKC

The header shows the station identifier, issue time, and valid period — specifically, the valid period tells you exactly how long the forecast applies. In our example, 1412/1512 means the forecast is valid from the 14th at 1200Z through the 15th at 1200Z. The base conditions on the first line apply until the first change group takes effect. Additionally, each change group specifies the type of change and the exact time window for that transition.

TAF Change Groups

In our example, the FM1800 group means a permanent change at 1800Z — winds increase and scattered clouds develop at 4,000 feet. Furthermore, the TEMPO 2000/2200 group warns of temporary thunderstorms with a broken cumulonimbus deck at 2,500 feet. As a result, any pilot planning an arrival between 2000Z and 2200Z should treat that window with real caution and plan for an alternate. BECMG 2200/2300 then indicates a gradual return to calm winds and clear skies after the convective period passes.

Go/No-Go Decision Making

Raw weather data only matters when you act on it correctly. Here’s how to combine METARs and TAFs effectively for every preflight decision.

Applying METAR Data to Your Preflight Decision

Check the trend, not just the snapshot. A single METAR is one moment in time. Specifically, pull the last two or three METARs for your destination to see whether visibility and ceilings are improving or deteriorating. A destination showing 1,500-foot ceilings means something very different when the previous hour showed 3,000 feet (falling trend) versus 800 feet (rising trend).

Identify your weather window using the TAF. Cross-reference your planned arrival time against every TAF change group. If a TEMPO or FM group introduces IFR conditions near your ETA, build a margin by targeting an earlier arrival or selecting a proper alternate. Additionally, thunderstorm TEMPO groups deserve extra-wide margins — convection rarely runs on schedule, and CB is one of the things in aviation where being early is always the right call.

Set and hold your personal minimums. Legal minimums and safe minimums are not the same thing. Therefore, establish your own ceiling and visibility floors before the briefing — not during it. For VFR cross-countries, a reasonable starting point is at least 500 feet above the legal VFR minimum and 3SM visibility as a personal floor. However, always adjust based on terrain, airspace complexity, and your own recent flight currency.

Check METARs along the entire route. For cross-country flights, pull METARs from airports roughly 50 to 75 miles apart along your whole route — not just departure and destination. Consequently, this gives you a picture of the corridor you’ll actually be flying, not just the endpoints. Areas where multiple adjacent stations show declining conditions often indicate a developing system moving into your path.

Where to Find METARs and TAFs

Several reliable, free resources give you direct access to current METAR and TAF data for flight planning:

• aviationweather.gov — The official FAA/NOAA source. Specifically, the METAR page allows you to pull decoded or raw reports for any ICAO station. The regional map view shows conditions across your entire route at a glance.
• 1800wxbrief.com — Standard Weather Briefing Service. Furthermore, filing a standard briefing here creates a legal record of your preflight weather check, which supports both safety and liability documentation.
• SkyVector — Free web-based flight planning with METAR overlays directly on the sectional chart view. Therefore, it’s a practical quick-reference tool for VFR cross-country planning without a subscription.
• ForeFlight / Garmin Pilot — Both apps display METARs and TAFs integrated with route planning and NOTAMs. However, full access requires a subscription.

For mobile preflight, the free Aviation Weather Center app also provides direct METAR and TAF access without a paywall. Additionally, for flights to remote areas with limited cell service, download current weather data before departure — don’t count on pulling it en route when you need it most.

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