Reading METAR and TAF Reports for UK Drone Pilots

What Are METAR and TAF Reports?

METAR (Meteorological Aerodrome Report) is a standardised format for reporting current weather conditions at an aerodrome. TAF (Terminal Aerodrome Forecast) uses a similar format but provides a forecast, typically covering 9 to 30 hours ahead. Both originate from the International Civil Aviation Organisation (ICAO) coding system and are used by manned aviation worldwide.

As a drone pilot operating under the UK Civil Aviation Authority (CAA) rules, you are not legally required to decode METAR and TAF reports. However, the CAA recommends that all remote pilots assess weather conditions before flight. Understanding these reports gives you access to the same data that crewed aircraft pilots rely on.

Where to Find METAR and TAF Data

• Met Office Aviation Briefing Service — provides decoded and raw METAR/TAF for UK aerodromes
• OGIMET — an independent aggregator that displays worldwide METAR data
• NATS Aeronautical Information Service (AIS) — the official UK source for aeronautical information, including weather
• Aviation weather apps — several mobile apps decode METAR and TAF automatically

Reading a METAR Report

A typical UK METAR looks like this:

METAR EGLL 290850Z 24012KT 9999 FEW040 17/09 Q1023=

Breaking It Down

• EGLL — the ICAO code for the aerodrome (London Heathrow)
• 290850Z — date and time in UTC (29th of the month at 08:50 UTC)
• 24012KT — wind from 240 degrees at 12 knots
• 9999 — visibility of 10 km or more
• FEW040 — few clouds at 4,000 feet
• 17/09 — temperature 17 degrees Celsius, dew point 9 degrees Celsius
• Q1023 — atmospheric pressure (QNH) of 1023 hPa

Wind Codes That Matter for Drone Pilots

• VRB — variable wind direction (common in light winds below 3 knots)
• G — gusts (e.g., 24012G25KT means wind at 12 knots gusting to 25 knots)
• 00000KT — calm conditions

Many consumer drones have wind resistance ratings around 10 to 12 m/s (approximately 19 to 23 knots). If the METAR shows sustained winds or gusts above your drone's rated resistance, postpone the flight.

Visibility Codes

• 9999 — 10 km or more (excellent)
• 5000 — 5 km (adequate for most visual line of sight operations)
• 0200 — 200 metres (too low for safe drone flight in nearly all circumstances)

Under the CAA's rules for Open Category operations, you must maintain visual line of sight (VLOS) with your drone at all times. Poor visibility directly affects your ability to do this.

Cloud Cover Codes

• SKC — sky clear
• FEW — 1 to 2 oktas (eighths of sky covered)
• SCT — 3 to 4 oktas (scattered)
• BKN — 5 to 7 oktas (broken)
• OVC — 8 oktas (overcast)

Low cloud ceilings can affect lighting conditions and make it harder to see your drone against the sky. Open Category drone flights must stay below 120 metres (400 feet) AGL, so cloud at or below that altitude is particularly relevant.

Reading a TAF Report

A TAF follows a similar structure but includes forecast periods and change indicators:

• BECMG — conditions becoming (a gradual change expected)
• TEMPO — temporary conditions (lasting less than an hour at a time)
• PROB30 / PROB40 — probability of occurrence (30% or 40%)

If a TAF shows TEMPO conditions with gusts exceeding your drone's tolerance, plan your flight window for the calmer periods — or postpone entirely.

Practical Tips for Drone Pilots

• Check the METAR for the nearest aerodrome to your flying site — it is the closest professional weather observation available
• Compare the METAR with a local forecast (Met Office or a weather app) since conditions can vary significantly even a few miles from the aerodrome
• Use the TAF to identify windows of favourable weather if the day is changeable
• Remember that METAR wind speeds are measured at 10 metres above ground — wind at your drone's operating altitude may be stronger
• Always conduct your own on-site weather assessment as well, as conditions can change rapidly