Decoding Aviation Weather: How to Read METARs and TAFs Like a Pro

19 Degree East

Oct 3

2 min read

To an untrained eye, raw aviation weather reports look like encrypted code from an old teleprinter. But for student pilots, mastering these strings is fundamental not just to clear your DGCA Meteorology written exam, but to make confident, safe go/no-go decisions in the cockpit.

Once you know the standard sequence, decoding them takes seconds. Let’s break down both reports using real-world data from Delhi’s Indira Gandhi International Airport (VIDP).

1. Decoding a METAR (Current Surface Weather)

A METAR reports observed conditions at an airfield at a specific moment in time.

Plaintext

METAR VIDP 030930Z 28010KT 5000 HZ NSC 36/15 Q1011 NOSIG=

METAR VIDP: Routine observation at Indira Gandhi International Airport, New Delhi.
030930Z: Issued on the 3rd at 09:30 UTC (15:00 IST).
28010KT: Wind from 280° True at 10 knots (steady westerly flow aligning with RWY 28/29).
5000: Visibility is 5,000 metres (5 km).
HZ: Weather phenomenon, Haze.
NSC: Nil Significant Cloud (no clouds below 5,000 ft or sector minimum; no CB/TCU).
36/15: Temperature 36°C / Dewpoint 15°C. A wide 21°C spread means dry air, but high ambient heat drives density altitude well above field elevation.
Q1011: Altimeter setting (QNH) is 1011 hPa.
NOSIG=: No significant change expected over the next two hours.

2. Reading a TAF (Aerodrome Forecast)

While a METAR shows current weather, a TAF forecasts conditions within an 8 km radius of the airfield over the next 24 to 30 hours.

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TAF VIDP 030800Z 0309/0318 29008KT 5000 HZ NSC BECMG 0315/0317 34006KT 4000 HZ BR=

030800Z: Issued on the 3rd at 08:00 UTC.
0309/0318: Valid from 09:00 UTC to 18:00 UTC on the 3rd (14:30 to 23:30 IST).
29008KT 5000 HZ NSC: Initial baseline forecast, wind 290° at 8 knots, 5 km visibility in haze, no significant cloud.
BECMG 0315/0317: A gradual transition occurring between 15:00 UTC and 17:00 UTC (20:30 to 22:30 IST).
34006KT 4000 HZ BR=: By 17:00 UTC, winds back to 340° at 6 knots, and visibility drops to 4,000 metres as cooling air forms mist (BR) alongside haze (HZ).

Quick Reference: Weather Acronyms at a Glance

Obscurations: HZ (Haze), BR (Mist, vis< 1,000 m), FG (Fog, vis< 1,000 m), FU (Smoke).
Precipitation: RA (Rain), DZ (Drizzle), TS (Thunderstorm), SH (Showers).
The Ceiling Rule: Only BKN (Broken, 5/8–7/8) and OVC (Overcast, 8/8) count as legal operational ceilings. FEW and SCT do not.

Turn Raw Teletype into Second Nature

Cracking questions on METARs, TAFs, and density altitude is one of the quickest ways to clear in your DGCA Meteorology paper, if you have the right frameworks in place.

At 19° Degree East, we simplify the entire ground school syllabus into clear, structured concepts with rigorous DGCA-focused practice.

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Subjects Covered: Air Navigation • Meteorology • Air Regulations • Technical General
Format: Concept-first theory, regular mock tests, and 1-on-1 faculty mentorship.
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