Definition
A METAR (Meteorological Aerodrome Report) is the primary surface-level aviation weather product, providing a snapshot of actual atmospheric conditions at a specific location and time. It is standardized globally under ICAO Annex 3 (Meteorological Service for International Air Navigation) and WMO Technical Regulations No. 49, Volume II, Part 1 — the same publication series designated Tech Reg 49.3. Within the United States, METARs are disseminated by the FAA and National Weather Service, with operational requirements for air carrier operators formalized in 14 CFR §121.97 (airport weather minimums for Part 121) and reinforced across Part 135 and Part 91 preflight planning obligations under §91.103.
The METAR format follows a fixed sequence: report type (METAR for routine, SPECI for a special unscheduled observation), the ICAO four-letter station identifier, the observation date-time group in DDHHMMZ format, wind direction and speed in degrees true and knots (or meters per second in some ICAO states), wind gusts when they exceed mean speed by 10 kt or more, prevailing visibility (statute miles in the FAA/US system; meters in the ICAO/EASA system), present weather phenomena using standard two-letter descriptors (RA = rain, SN = snow, FZRA = freezing rain, TS = thunderstorm, BR = mist, FG = fog, BLSN = blowing snow, and approximately 40 additional codes), sky condition layers using coverage fractions (FEW = 1–2 oktas, SCT = 3–4 oktas, BKN = 5–7 oktas, OVC = 8 oktas) plus height in hundreds of feet AGL, and a vertical visibility figure (VV) when sky is obscured. Temperature and dewpoint follow in whole degrees Celsius, then the altimeter setting — reported with the prefix A and in inches of mercury (e.g., A2992) in the US, and with the prefix Q in hectopascals (e.g., Q1013) in ICAO/EASA states. The coded remarks (RMK) section that follows is FAA-specific and not part of the ICAO standard; it includes precision temperature/dewpoint to tenths of a degree, sea-level pressure, recent weather, and sensor status.
The SPECI is an unscheduled METAR issued whenever a significant change in conditions occurs between routine hourly observations. Trigger criteria include: ceiling dropping to or below 3,000, 1,500, 1,000, or 500 ft; visibility decreasing to or below 3, 2, 1 SM or ½ SM; a tornado, funnel cloud, or waterspout reported; hail of any size; wind shift; or any wind reaching or exceeding 25 kt from a calm condition. The SPECI format is identical to METAR; only the header word differs.
For pilot certification purposes, the ability to decode METARs is tested on all FAA Airman Knowledge Tests from Private Pilot through ATP, and correct interpretation is evaluated on all practical tests. ICAO states examine METAR decoding under EASA Part-FCL Annex I theoretical knowledge syllabi. METARs feed into the go/no-go decision for every individual flight, into dispatch release documents for Parts 121 and 135, into fuel calculations that require actual winds and temperature, and into automated terminal information service (ATIS) broadcasts updated with each new observation.
Why It Matters for Flight Schools
For flight school dispatchers and chief flight instructors, the METAR is the most time-sensitive weather product reviewed before any training sortie. A ceiling that drops from 3,000 ft BKN to 1,500 ft OVC between the preflight briefing and the student's engine start can invalidate the planned lesson entirely. Schools operating VFR-only training fleets need their dispatchers checking the current METAR against school-defined minima before confirming every booking, and checking subsequent METARs during long lessons to determine whether conditions remain adequate for the student to continue or return.
METAR interpretation is also core training content across the PPL, instrument rating, and CPL syllabi. Instructors spend significant ground time teaching students to decode each field correctly and to identify the weather phenomena combinations that indicate rapidly deteriorating conditions — for example, TSRA with a falling altimeter and temperature-dewpoint spread of 1°C signals convective weather that can make conditions unflyable within minutes. Flight schools that integrate live METAR data into their training platforms create teachable moments out of every preflight briefing, accelerating a skill that is tested on every FAA and EASA practical examination.
How Aviatize Handles This
Aviatize's smart planning and booking module can surface the current METAR for each training airport alongside the daily schedule, giving dispatchers a real-time weather picture without requiring them to navigate to a separate briefing tool. When a METAR shows conditions at or below school-configured VFR or IFR training minima, the system can flag affected bookings for dispatcher review, preventing students and instructors from showing up for a lesson that will be a guaranteed cancellation before the aircraft leaves the ramp.
For training record purposes, Aviatize can associate the METAR observation at the time of each lesson with the flight log entry, building a searchable weather-versus-performance record over time. This supports audits under 14 CFR Part 141 or EASA Part-ATO by demonstrating that each solo or cross-country flight was conducted in conditions that met the applicable minima — a documentation requirement that otherwise falls entirely on manual instructor notes.