metar.cloud — Real-Time Aviation Weather for Pilots Worldwide
metar.cloud is a free aviation weather platform delivering real-time METAR reports and TAF forecasts for thousands of airports worldwide. Designed for pilots, student pilots, flight dispatchers, and aviation enthusiasts, the application presents decoded weather observations alongside interactive wind direction compasses, cloud layer visualizations, runway wind component calculations, and TAF timeline charts. Whether you are planning a cross-country flight or checking conditions at your local airfield, metar.cloud provides the data you need in a clear, visual format — accessible on web, iOS, and Android devices.
Features include real-time METAR decoding with flight category indicators (VFR, MVFR, IFR, LIFR), animated wind compass with runway overlay, cloud layer altitude charts, crosswind and headwind/tailwind calculations for every runway, TAF forecast timeline with change group visualization, nearby airport weather comparison, sunrise and sunset daylight timeline, METAR history tracking, and a favorites system for quick access to frequently checked airports. All data is sourced from the Aviation Weather Center and refreshed every minute.
What is a METAR?
METAR stands for Meteorological Aerodrome Report. It is a standardized weather observation format used at airports and military airbases around the world. METARs are typically issued once per hour, or half-hourly at busy airports, and provide a snapshot of current conditions including wind direction and speed, prevailing visibility, cloud cover and heights, temperature, dew point, and barometric pressure. When weather changes significantly between scheduled observations, a special report called a SPECI is issued immediately.
A typical METAR follows the ICAO Annex 3 format. It begins with the station identifier (four-letter ICAO code such as KJFK or EGLL), followed by the date and time of observation in Zulu (UTC). The wind group reports direction in degrees true north and speed in knots. Visibility is given in statute miles in the United States or meters internationally. Cloud layers are encoded as FEW (1–2 oktas), SCT or scattered (3–4 oktas), BKN or broken (5–7 oktas), or OVC or overcast (8 oktas) with their height above ground level in hundreds of feet. Temperature and dew point are reported in degrees Celsius, and the altimeter setting provides sea-level adjusted barometric pressure in inches of mercury or hectopascals.
Example METAR: KJFK 031556Z 31012G20KT 10SM FEW045 BKN250 22/11 A3002. This tells us JFK airport observed on the 3rd at 15:56 Zulu, wind from 310 degrees at 12 knots gusting to 20, visibility 10 statute miles, few clouds at 4,500 feet, broken clouds at 25,000 feet, temperature 22°C, dew point 11°C, and altimeter setting 30.02 inHg.
What is a TAF?
TAF stands for Terminal Aerodrome Forecast. It is a weather forecast issued for the airspace within five statute miles of an airport, typically covering a 24- to 30-hour period. TAFs are issued four times per day at major airports and use a coded format similar to METARs. They describe expected weather conditions including wind, visibility, cloud cover, and significant weather phenomena such as thunderstorms, fog, or freezing precipitation.
TAFs use change groups to describe how weather is expected to evolve over the forecast period. FM (from) indicates an abrupt change at a specific time. BECMG (becoming) indicates a gradual transition over a one- or two-hour window. TEMPO (temporary) indicates conditions that may briefly occur for less than half the period. PROB groups indicate the probability — usually 30 percent or 40 percent — of certain conditions developing. Pilots use TAFs alongside METARs for preflight planning and in-flight decision-making, as TAFs provide the forward-looking weather picture essential for safe flight operations.
Understanding Flight Categories
Aviation weather conditions are classified into four flight categories based on ceiling height and prevailing visibility. These categories help pilots quickly assess whether conditions are suitable for visual or instrument flight and are color-coded on aviation weather maps and applications.
VFR (Visual Flight Rules) — Green. Ceiling above 3,000 feet AGL and visibility greater than 5 statute miles. These are the best flying conditions, and most general aviation flights operate under VFR. Pilots flying under visual flight rules navigate by visual reference to the ground and other landmarks.
MVFR (Marginal Visual Flight Rules) — Blue. Ceiling between 1,000 and 3,000 feet AGL or visibility between 3 and 5 statute miles. Marginal VFR requires extra caution and enhanced situational awareness. Student pilots and lower-time pilots should exercise particular care or consider delaying flight when MVFR conditions are reported or forecast.
IFR (Instrument Flight Rules) — Red. Ceiling between 500 and 999 feet AGL or visibility between 1 and less than 3 statute miles. IFR conditions require an instrument rating, a filed instrument flight plan, and ATC clearance. Pilots must rely on flight instruments rather than visual references to maintain safe flight.
LIFR (Low Instrument Flight Rules) — Magenta. Ceiling below 500 feet AGL or visibility less than 1 statute mile. These are the most restrictive conditions and pose significant challenges even for experienced instrument-rated pilots. LIFR may result in airport closures, approach minimums not being met, and diversions to alternate airports.
Key Weather Elements for Aviation
Wind is one of the most critical weather elements for pilots. METARs report wind direction — where the wind is blowing from — in degrees true north and speed in knots. Variable winds are noted when direction varies by 60 degrees or more at speeds above 6 knots. Gusts, which are sudden brief increases in wind speed, are reported when the peak speed exceeds the sustained speed by 10 knots or more. Crosswind and headwind/tailwind components for each runway help pilots assess takeoff and landing conditions.
Visibility indicates the greatest horizontal distance at which prominent objects can be identified. Reduced visibility can result from fog, mist, haze, rain, snow, dust, smoke, or volcanic ash. Runway Visual Range (RVR) provides a more precise measurement for specific runways during low-visibility conditions and is reported in hundreds of feet.
Cloud coverage affects both flight category and pilot decision-making. The ceiling — defined as the lowest broken (BKN) or overcast (OVC) layer — directly determines flight category. Cumulonimbus (CB) clouds indicate thunderstorm activity and are always reported due to their association with severe turbulence, icing, wind shear, and hail. Towering cumulus (TCU) clouds are precursors to CB development and warrant close monitoring.
Temperature and dew point spread is an important indicator of moisture and fog potential. When the spread narrows below 3 degrees Celsius, fog or low clouds are likely to form. The altimeter setting — barometric pressure adjusted to sea level — is essential for accurate altitude readings. An incorrect altimeter setting can lead to dangerous altitude errors, especially in mountainous terrain or during instrument approaches.
Common weather phenomena in METARs include thunderstorms (TS), rain (RA), snow (SN), drizzle (DZ), fog (FG), mist (BR), haze (HZ), freezing rain (FZRA), freezing drizzle (FZDZ), ice pellets (PL), dust storms (DS), sandstorms (SS), and volcanic ash (VA). Intensity qualifiers range from light (minus sign) to moderate (no prefix) to heavy (plus sign). Vicinity (VC) indicates phenomena observed near but not at the airport.
Notable Airports Around the World
KJFK — John F. Kennedy International Airport in New York is the busiest international air passenger gateway to the United States, handling over 62 million passengers annually. Named after the 35th president, the airport sits on the shores of Jamaica Bay in Queens and features four runways, including 13L/31R at 14,511 feet — one of the longest commercial runways in North America. JFK was originally named Idlewild Airport when it opened in 1948.
EGLL — London Heathrow handles over 80 million passengers per year despite having only two parallel runways. Operational since 1946, Heathrow is famous for its strict noise abatement procedures including alternating runway use throughout the day. Landing slots at Heathrow are among the most valuable in aviation — a single pair has been traded for over 75 million dollars.
RJTT — Tokyo Haneda Airport is the busiest airport in Asia by domestic passenger traffic. Originally opened in 1931, it has undergone major expansions including a fourth runway built on reclaimed land in Tokyo Bay. Its international terminal features a replica Edo-period Japanese town and the airport consistently ranks among the world’s cleanest.
KATL — Hartsfield-Jackson Atlanta International is the world’s busiest airport by passenger traffic, with over 93 million travelers annually. Named after two former Atlanta mayors, it has held the title of busiest airport for over two decades. Its five parallel runways and underground people mover connecting seven concourses make it one of the most efficient hub airports in the world. Delta Air Lines operates its largest hub here.
LFPG — Paris Charles de Gaulle Airport is the largest international airport in France and the second busiest in Europe. Its distinctive circular Terminal 1, designed by architect Paul Andreu, was revolutionary when it opened in 1974. CDG spans over 32 square kilometers and serves as the main hub for Air France. The airport has four runways and handles both heavy European traffic and long-haul intercontinental routes.
OMDB — Dubai International Airport connects East and West as one of the world’s busiest international airports, handling over 87 million passengers annually. Home base of Emirates airline, it features Terminal 3, one of the largest airport buildings in the world by floor space. Remarkably, the airport sits just 4 kilometers from the Dubai city center, making it one of the most conveniently located major airports on Earth.
KLAX — Los Angeles International Airport is the busiest on the US West Coast and famous for its mid-century Theme Building, a futuristic structure built in 1961 in the Googie architectural style. LAX has four parallel runways and nine passenger terminals arranged in a horseshoe shape. It serves as the primary gateway for flights across the Pacific to Asia and Oceania.
VHHH — Hong Kong International Airport was built on the artificial island of Chek Lap Kok, replacing the legendary Kai Tak Airport in 1998. Kai Tak was notorious for its dramatic curved approach requiring pilots to make a 47-degree turn at low altitude over Kowloon City. The modern airport is one of the world’s busiest cargo hubs, processing over 5 million tonnes of freight annually.
WSSS — Singapore Changi Airport is consistently voted the world’s best airport. It features the Jewel complex with the world’s tallest indoor waterfall called the Rain Vortex, a butterfly garden housing over 1,000 tropical butterflies, a rooftop swimming pool, and a two-story slide. Changi is a major Southeast Asian aviation hub handling over 65 million passengers through four terminals.
EDDF — Frankfurt Airport is Germany’s busiest and a critical European hub for Lufthansa. It features four runways and two terminals connected by the SkyLine automated people mover. Frankfurt is one of the few airports in the world with a long-distance railway station built directly into the terminal complex, connecting to Germany’s high-speed ICE train network. It also hosts the world’s largest airport-based aircraft maintenance facility.