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Understanding Airport Weather Forecasts: A Comprehensive Guide

June 22, 2026 · The Clime Team

Airport weather forecasts are essential for ensuring safe and efficient flight operations. Two primary types of aviation weather reports are METARs and TAFs, each serving distinct purposes.

What Are METARs and TAFs?

METARs (Meteorological Aerodrome Reports) are standardized, coded weather observations issued at regular intervals—typically every hour or half-hour. They provide real-time data on current surface conditions at specific airports, including:

Wind: Speed and direction.
Visibility: Distance at which objects can be clearly seen.
Cloud Cover: Types and amounts of clouds present.
Temperature and Dew Point: Indicating moisture levels.
Pressure: Atmospheric pressure readings.

TAFs (Terminal Aerodrome Forecasts), on the other hand, are aviation-specific forecasts predicting weather conditions at an airport for the next 24 to 30 hours. They assist pilots and air traffic controllers in planning by detailing expected:

Wind: Speed and direction.
Visibility: Forecasted distances.
Cloud Cover: Anticipated cloud formations.
Precipitation: Expected rain, snow, or other forms.

How Are METARs and TAFs Structured?

Both METARs and TAFs follow standardized formats to ensure consistency and clarity.

METAR Structure:

Station Identifier: Four-letter ICAO airport code.
Date and Time: Day of the month and time in UTC.
Wind: Direction in degrees and speed in knots.
Visibility: Measured in meters or statute miles.
Weather Phenomena: Codes for rain, snow, fog, etc.
Cloud Cover: Height and type of clouds.
Temperature and Dew Point: In degrees Celsius.
Pressure: Altimeter setting in inches of mercury.

TAF Structure:

Station Identifier: Four-letter ICAO airport code.
Date and Time of Issue: Time the forecast was issued.
Forecast Period: Start and end times of the forecast.
Wind: Direction in degrees and speed in knots.
Visibility: Forecasted distances.
Weather Phenomena: Anticipated weather events.
Cloud Cover: Expected cloud formations.
Change Indicators: Terms like 'BECMG' (becoming), 'TEMPO' (temporary), and 'FM' (from) to indicate changes.

How to Read a METAR

Decoding a METAR involves understanding its structured format. For example:

METAR KATL 121753Z 27015G25KT 10SM SCT030 BKN250 15/M02 A3000 RMK AO2 SLP265

KATL: Atlanta International Airport.
121753Z: 12th day of the month at 1753 UTC.
27015G25KT: Wind from 270° at 15 knots, gusting to 25 knots.
10SM: Visibility 10 statute miles.
SCT030: Scattered clouds at 3,000 feet above ground level.
BKN250: Broken clouds at 25,000 feet above ground level.
15/M02: Temperature 15°C, dew point -2°C.
A3000: Altimeter setting 30.00 inches of mercury.

For a detailed guide on reading METARs, refer to Aviatopia's How to Read a METAR.

How to Read a TAF

Interpreting a TAF requires understanding its components. For example:

TAF KATL 121730Z 1218/1324 31012KT P6SM FEW040 BKN250
  FM122200 28015G25KT 4SM -RA BKN020
  TEMPO 1222/1302 2SM RA OVC015
  FM130600 33008KT P6SM SCT030 BKN100
  BECMG 1312/1314 SKC

KATL: Atlanta International Airport.
121730Z: 12th day of the month at 1730 UTC.
1218/1324: Forecast valid from 12th at 1800 UTC to 13th at 2400 UTC.
31012KT: Wind from 310° at 12 knots.
P6SM: Visibility greater than 6 statute miles.
FEW040: Few clouds at 4,000 feet above ground level.
BKN250: Broken clouds at 25,000 feet above ground level.
FM122200: From 12th at 2200 UTC, expect the following conditions.
28015G25KT: Wind from 280° at 15 knots, gusting to 25 knots.
4SM: Visibility 4 statute miles.
-RA: Light rain.
BKN020: Broken clouds at 2,000 feet above ground level.
TEMPO 1222/1302 2SM RA OVC015: Temporary conditions between 12th at 2200 UTC and 13th at 0200 UTC: visibility 2 statute miles, rain, overcast clouds at 1,500 feet above ground level.
FM130600: From 13th at 0600 UTC, expect the following conditions.
33008KT: Wind from 330° at 8 knots.
SCT030: Scattered clouds at 3,000 feet above ground level.
BECMG 1312/1314 SKC: Becoming clear skies between 13th at 1200 UTC and 1400 UTC.

For a comprehensive guide on reading TAFs, refer to Aviatopia's How to Read a TAF.

How to Access METARs and TAFs

In the United States, METARs and TAFs are issued by the National Weather Service (NWS) for nearly 700 airports. These reports are typically available through aviation weather services, flight planning tools, and official NWS websites.

Why Are METARs and TAFs Important?

Both METARs and TAFs are crucial for flight safety and operational planning. While METARs provide current weather conditions, TAFs offer forecasts that help anticipate and prepare for changing weather patterns. Understanding and accurately interpreting these reports is essential for pilots, air traffic controllers, and airline operations teams to make informed decisions and ensure safe flight operations.

For more detailed information on aviation weather reports, consider exploring resources like Aviatopia's Aviation Weather Explained.