What is a METAR and why does it matter for drone operations?

A METAR (Meteorological Aerodrome Report) is a standardized, routine aviation weather observation that reports current surface conditions at an airport, including wind speed and direction, visibility, sky condition, temperature, dew point, and altimeter setting. For Part 107 remote pilots, METARs from the nearest reporting station give the best available snapshot of actual atmospheric conditions before and during a sUAS flight. Because Part 107 requires remote pilots to ensure safe operating conditions, consulting the most recent METAR is a fundamental step in pre-flight weather planning. The FAA's Pilot's Handbook of Aeronautical Knowledge (PHAK) and the Aviation Weather Handbook both identify METARs as a primary weather product for pre-flight decision-making.

What is the difference between a METAR and a TAF for remote pilots studying for the FAA Unmanned Aircraft General – Small knowledge test?

A METAR reports observed, real-time weather conditions at a specific location, while a TAF (Terminal Aerodrome Forecast) is a forecast of expected weather conditions for an area within approximately 5 statute miles of an airport, typically covering a 24- or 30-hour period. Remote pilots use METARs to assess current conditions and TAFs to anticipate how weather may change during a planned flight window. Understanding both products is directly tested on the FAA Unmanned Aircraft General – Small knowledge test and is essential for sound aeronautical decision-making under 14 CFR Part 107. The Aviation Weather Handbook notes that TAFs follow the same format conventions as METARs, making them easier to decode once you understand the standard coding.

How do you read wind information in a METAR for a sUAS pre-flight check?

Wind in a METAR is reported as a five- or seven-digit group where the first three digits indicate the true direction the wind is coming from (in degrees), and the next two digits show the speed in knots; gusts, if present, are shown after a 'G' followed by the peak gust speed (e.g., '27015G25KT' means wind from 270° at 15 knots gusting to 25 knots). Variable wind direction is indicated by 'VRB' in place of the direction digits, and calm winds are coded as '00000KT.' Part 107 remote pilots must pay close attention to both sustained wind speed and gust values because high or gusty winds can exceed the performance limits of small UAS and create unsafe flight conditions. The FAA recommends comparing METAR wind data against the sUAS manufacturer's operating limitations before every flight.

METARs and TAFs for sUAS Operations

Before launching any drone under 14 CFR Part 107, a remote pilot in command (RPIC) is legally responsible for determining whether weather conditions are safe and legal for the planned operation. Two of the most powerful tools for that determination are the METAR (Meteorological Aerodrome Report) and the TAF (Terminal Aerodrome Forecast). These are the same weather products used by manned-aircraft pilots worldwide, and the FAA expects Part 107 remote pilots to know how to find, read, and apply them. Understanding METARs and TAFs is not just a knowledge-test requirement — it is a genuine safety skill that separates a professional remote pilot from a hobbyist guessing at the sky.

This article walks through the structure of each product, how to decode the coded format, what the numbers mean for sUAS operations specifically, and the practical traps that appear on the FAA Unmanned Aircraft General — Small (UAG) knowledge test.

What Is a METAR?

A METAR is an observed weather report generated at an airport (or other reporting station) at a fixed time — typically every hour on the hour, with SPECI (special observation) reports issued any time conditions change significantly between scheduled reports. Because METARs reflect actual, current conditions at a specific location, they are the closest thing a remote pilot has to a verified snapshot of the real atmosphere.

METARs are issued in a standardized coded format recognized internationally. Here is a simplified example:

METAR KORD 151553Z 27015KT 10SM SCT040 BKN080 22/14 A3002 RMK AO2

Breaking this down element by element:

METAR — report type (METAR = routine; SPECI = special).
KORD — ICAO station identifier (Chicago O'Hare).
151553Z — date and time: the 15th day of the month at 1553 UTC (Zulu time).
27015KT — wind from 270° (due west) at 15 knots. If gusts were present, it would read, for example, 27015G25KT (gusts to 25 knots).
10SM — visibility 10 statute miles. Note that METARs report visibility in statute miles, matching Part 107 operational minimums.
SCT040 BKN080 — scattered clouds at 4,000 feet AGL; broken clouds at 8,000 feet AGL. Cloud heights in METARs are always in hundreds of feet AGL.
22/14 — temperature 22°C, dew point 14°C. A small spread between these values (roughly 4°C or less) indicates high relative humidity and potential fog formation.
A3002 — altimeter setting 30.02 inches of mercury.
RMK AO2 — remarks; AO2 indicates the station has a precipitation discriminator.

For Part 107 operations, the most operationally critical elements are wind speed and direction, visibility, and cloud layers. Part 107.51 requires the RPIC to know these three quantities before flight and during flight.

What Is a TAF?

A TAF is a forecast — a prediction of future weather conditions at an airport, typically covering a 24-hour period (some major international airports issue 30-hour TAFs). TAFs are issued four times daily at 0000Z, 0600Z, 1200Z, and 1800Z. Because they are forecasts, TAFs involve inherent uncertainty that METARs do not, but they are essential for planning operations hours in advance.

A simplified TAF example:

TAF KORD 151130Z 1512/1612 27012KT P6SM BKN050 TEMPO 1514/1518 5SM TSRA OVC030 FM152000 24008KT P6SM SKC

Key elements:

TAF KORD 151130Z — TAF for Chicago O'Hare, issued on the 15th at 1130Z.
1512/1612 — valid period: from the 15th at 1200Z to the 16th at 1200Z.
27012KT P6SM BKN080 — prevailing forecast: winds 270° at 12 knots, visibility greater than 6 statute miles, broken clouds at 8,000 feet AGL.
TEMPO 1514/1518 — temporary conditions expected between 1400Z and 1800Z on the 15th. Temporary changes last less than one hour at a time and cover less than half the period.
5SM TSRA OVC030 — during that TEMPO window: 5 miles visibility, thunderstorms and rain, overcast at 3,000 feet AGL.
FM152000 — from the 15th at 2000Z: conditions improve to winds 240° at 8 knots, visibility greater than 6 statute miles, sky clear.

TAF change groups include FM (from — a permanent change), TEMPO (temporary — less than half the period), and BECMG (becoming — a gradual change that completes within the stated window). Recognizing these terms lets a remote pilot decide whether a deteriorating forecast is brief or sustained.

Why METARs and TAFs Matter for Part 107 Operations

Part 107 sets specific weather minimums that directly map to METAR and TAF data. Under 14 CFR 107.51, a small UAS may not be operated when:

Flight visibility is less than 3 statute miles from the control station.
The aircraft flies closer than 500 feet below or 2,000 feet horizontally from clouds.

These limits exist because sUAS operations must remain compatible with manned aircraft in the same airspace. A METAR's visibility field and cloud layer data tell you immediately whether you are legal to fly. For example, if a METAR reports OVC005 (overcast at 500 feet AGL), a remote pilot operating near that station would face a cloud ceiling that almost certainly violates the 500-foot-below rule — and possibly the visibility minimum as well.

Wind data from METARs is equally important. While Part 107 itself does not specify a maximum wind speed, the aircraft's manufacturer operating limits (found in the sUAS documentation) do. Winds reported in METARs are measured at 10 meters (approximately 33 feet) AGL at the reporting station; actual winds at your operating altitude may be different, especially near terrain, structures, and in thermal activity. Remote pilots should treat reported winds as a baseline and consider that winds often increase with altitude.

Temperature and dew point spread can warn of fog, mist, or low stratus forming — conditions that reduce visibility rapidly. When the spread is 5°C or less, fog is possible; at 3°C or less, it becomes likely.

How to Access METARs and TAFs

The FAA and NOAA make METARs and TAFs freely available through several channels:

aviationweather.gov — the official NOAA Aviation Weather Center website, offering METARs, TAFs, winds-aloft forecasts, SIGMETs, and graphical products.
1800wxbrief.com (Leidos Flight Service) — the official FAA-contracted weather briefing service; remote pilots can register and receive standard briefings.
ForeFlight, Garmin Pilot, and similar apps — commercially developed apps that pull official data from aviationweather.gov and display it in user-friendly formats.

Regardless of how you access the data, always confirm you are viewing current products. An hourly METAR becomes stale quickly in rapidly changing conditions; always check the time stamp.

Key Numbers and Rules

3 statute miles — minimum flight visibility required under Part 107.51.
500 feet below clouds — minimum vertical distance from clouds for sUAS.
2,000 feet horizontally from clouds — minimum horizontal distance from clouds for sUAS.
METARs issued hourly — SPECI issued for significant changes between hours.
TAF valid period: 24 hours (30 hours at select locations), issued 4 times daily.
Cloud heights in METARs are in hundreds of feet AGL; BKN030 = 3,000 feet AGL.
Visibility in METARs is in statute miles — the same unit used in Part 107 minimums.
Wind speeds in METARs are in knots — 1 knot ≈ 1.15 mph. Convert if your aircraft specs list wind limits in mph.
A dew point spread of 5°C or less indicates elevated fog risk.

Common Test Traps

Confusing AGL with MSL for cloud heights. METAR cloud heights are always AGL, referenced to the airport elevation. This matters if your drone operating site is at a different elevation than the reporting station.
Misreading wind gusts. In 27015G28KT, the sustained wind is 15 knots but gusts reach 28 knots. Your aircraft must handle the gust value, not just the mean.
Treating a TAF as observed fact. A TAF is a forecast; actual conditions may differ. Always cross-check a recent METAR before launch.
Overlooking TEMPO groups. A TAF may show great prevailing conditions but embed a TEMPO window with thunderstorms and low visibility right during your planned flight time. Read the entire TAF, not just the opening line.
Assuming the nearest METAR applies perfectly to your site. METARs are point observations at airports. Conditions at your drone operation site — particularly in valleys, near large water bodies, or in urban heat islands — may differ. Use the METAR as your best available data but remain alert to local variations.

Mastering METARs and TAFs is a foundational skill that makes you a safer, more professional remote pilot. These products give you the meteorological situational awareness to plan legal flights, avoid hazardous conditions, and make smart go/no-go decisions — not just on the knowledge test, but on every flight you ever conduct.