Weather
metar & taf decoder
VFR and easy right now: a 1 kt wind, 10 km or more of visibility. The forecast turns: visibility down to 3.0 km setting in, 00:00Z to 09:00Z, 1 h 29 from now, 40% chance of visibility down to 300 m, 03:00Z to 09:00Z, 4 h 29 from now, and 30% chance of 300 ft ceilings, 09:00Z to 11:00Z, 10 h 29 from now.
No observed movement counts were supplied for this airfield, so nothing here is a claim about its traffic. What is shown is a wind-only inference. The wind direction is variable, and a wind with no settled direction favours no runway, so nothing here supports the end above.
Not derived from observed traffic, and not from a usable wind either. Not ATIS. Not an operational source. Density altitude is computed from the reported temperature and pressure at field elevation, not measured.
Raw METAR · observed 22:20Z
Tap any group to see what it says.
The observation, in plain English
At 22:20Z London Heathrow Airport reported VFR: wind variable in direction at 1 kt; visibility 10 km or more; no cloud detected by the automatic sensor (NCD). Temperature 14 °C with a dew point of 13 °C: a 1 °C spread, at or inside the 3 °C watch threshold, so mist or fog can form quickly. QNH 1030 hPa (30.42 inHg). The observation is fully automated, with no human observer: an automatic station can miss cloud type and some present weather.
TAF
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Each block is one hour of the validity, coloured by the category the forecast expects. Hatched blocks carry a TEMPO or PROB spell: those are possibilities, not the expected weather. A block with no colour is an hour whose period says nothing about visibility or cloud, so no category can be worked out. That is not the same as a clear hour. An hour whose period reports a broken or overcast layer at a height it does not give is uncoloured for the other reason: the cloud was stated and the ceiling cannot be read. The ringed block is the hour now. Across a BECMG window the worse of the old and new conditions is shown, because the change is only forecast to be complete by the end of it: an improvement appears when it is due, not when it starts.
Prevailing from the start of the validity:
Variable direction at 3 kt; 10 km or more; few (1-2 oktas) at 2,500 ft.
30% probability. That is a possibility, not a forecast that it will happen:
7 km.
Becoming, gradually across this period, and holding afterwards:
3 km; mist; shallow fog.
40% probability. That is a possibility, not a forecast that it will happen:
300 m; fog; sky obscured, vertical visibility at a height the station could not measure.
Becoming, gradually across this period, and holding afterwards:
10 km or more; no significant weather from here on.
30% chance of temporary spells, each under an hour. That is a possibility, not the forecast:
Broken (5-7 oktas) at 300 ft.
30% probability. That is a possibility, not a forecast that it will happen:
7 km.
Daylight
Sunset was 17:36Z · civil twilight ended 18:09Z · sunrise was 06:04Z
Night, for licensing purposes, began 18:09Z: the end of civil twilight, 33 min after sunset, and it is night now. Tomorrow’s dawn is not part of this calculation.
Computed from the aerodrome position and today’s date: a calculation, not an observation. Civil twilight is the sun 6° below the horizon.
Recent trend · last 4 observations
- 22:20ZVFR
METAR EGLL 032220Z AUTO VRB01KT 9999 NCD 14/13 Q1030latestno change - 21:20ZVFR
METAR EGLL 032120Z AUTO 08002KT 9999 SCT025 17/14 Q1030no change - 20:50ZVFR
METAR EGLL 032050Z AUTO VRB01KT 9999 FEW025 SCT036 17/14 Q1030no change - 20:20ZVFR
METAR EGLL 032020Z AUTO VRB02KT 9999 NCD 16/14 Q1030—
Steady: No change in the groups this strip compares.
Every delta is computed here by comparing consecutive reports on ceiling, visibility, wind, QNH and present weather. The station reports the rows, not the changes. Each row is a separate snapshot, so anything that happened in the gap between two of them was never observed. Pressure is shown but not counted towards the verdict. Wind is judged on speed alone (without a runway this strip cannot work out a crosswind), so a rising wind counts against the verdict and a falling one is reported without being counted for it.
Winds aloft over EGLL
forecast · Open-MeteoAsking Open-Meteo for the forecast over EGLL. Nothing is drawn here until it answers, and an empty chart is not calm air aloft.
Nearest alternatestap → same page for it
Asking the observation feed for the nearest reporting airfields. None is listed until it answers, which is not the same as there being none.
More numbers
Rel humidity
94%
from 14 / 13 °C
Press alt
−374 ft
457 ft below the field
ISA dev
−1.7 °C
vs 15.7 °C standard
T / Td in °F
57/55
same reading, other unit
All four are derived from the observation, not reported by it.
About EGLL
EGLL is London Heathrow Airport, country code GB. It lies at 51.4707°N, 0.4599°W, 83 ft above mean sea level. Its runways, as the aerodrome record lists them: 09L/27R and 09R/27L. Their live head and crosswind components are in the crosswind calculator, and the ends most likely in use now are worked out in the runway-in-use section further up this page. As a rule, routine METARs are issued hourly and half-hourly at busier aerodromes, with a SPECI whenever the weather changes sharply in between, and TAFs are reissued every six hours. That is the usual practice rather than this field’s published schedule, which is not held here.
Read further
For information and training only. Not an approved briefing source: always brief from the official service for your area before you fly.Observations and forecasts: NOAA’s Aviation Weather Center. Winds aloft: Open-Meteo. Sun times: computed here from the aerodrome’s position. Runway suggestion: computed here from the reported wind against the published runway alignments, and replaced by the observed runway where movements have been seen.