Meteorology made simple: reading METAR & TAF for DGCA

METAR and TAF reports look intimidating the first time you see one — a dense string of letters and numbers with no spaces. Once you learn the group order, though, they read almost like a sentence. Here's how to break one down, group by group.

METAR vs TAF — what's the difference?

A METAR (Meteorological Aerodrome Report) is an observation — what the weather actually was at a specific aerodrome at a specific time, issued hourly or half-hourly. A TAF (Terminal Aerodrome Forecast) is a forecast — what the weather is expected to do over the next 24–30 hours. DGCA questions often test whether you can tell these apart, and whether you know a TAF can include change groups (BECMG, TEMPO) that a plain METAR does not.

Decoding a METAR, group by group

Take a sample: METAR VABB 051030Z 24012KT 6000 HZ SCT018 BKN100 28/22 Q1008 NOSIG

• VABB — the ICAO station identifier (here, Mumbai).
• 051030Z — day of month (05) and time in UTC (1030Z).
• 24012KT — wind direction 240° true, speed 12 knots.
• 6000 — visibility in metres (6 km).
• HZ — present weather: haze.
• SCT018 BKN100 — cloud: scattered at 1,800 ft, broken at 10,000 ft.
• 28/22 — temperature 28°C, dew point 22°C.
• Q1008 — QNH (pressure setting) 1008 hPa.
• NOSIG — no significant change expected in the next two hours.

Notice the order never changes: station → time → wind → visibility → weather → cloud → temperature/dew point → pressure → trend. Once that order is second nature, unfamiliar reports stop being scary — you're just reading down a checklist.

Reading a TAF's change groups

A TAF adds forecast periods and change indicators that a METAR doesn't need:

• BECMG (becoming) — a gradual, permanent change expected within a stated time window.
• TEMPO (temporary) — a temporary fluctuation, each occurrence lasting less than an hour at a time, over a stated period.
• PROB30 / PROB40 — a probability (30% or 40%) of the stated conditions occurring.

Exam questions frequently ask you to identify which conditions apply at a specific time within the TAF's validity — this means reading the base forecast first, then checking whether any BECMG/TEMPO/PROB group overlaps that specific time.

Cloud amount codes — memorise these exactly

Cloud cover is reported in oktas (eighths of sky covered), grouped into: FEW (1–2 oktas), SCT scattered (3–4 oktas), BKN broken (5–7 oktas), and OVC overcast (8 oktas, full cover). DGCA loves testing the boundary values, so know exactly where each category starts and ends, not just the general idea.

Common present-weather abbreviations

A short list worth over-learning: RA rain, TS thunderstorm, FG fog, BR mist, HZ haze, SN snow, SH showers (used as a prefix, e.g. SHRA = rain showers), and intensity markers - (light) and + (heavy) placed before the code.

A study routine that works

Pull a real METAR/TAF for any major airport (they're publicly available) every day and decode it fully by hand before checking a reference. Ten reports a week, decoded properly, will make DGCA's weather-report questions some of the easiest marks on the paper.