Live wind and weather at Heathrow, and how the wind lines up with its two runways: headwind and crosswind for every runway end, with a map of the airfield, Heathrow's westerly preference and a way to try your own wind.
Northern runway 09L/27R (3,902 m) · Southern runway 09R/27L (3,660 m)
Wind and weather come from NOAA METAR reports for Heathrow (EGLL). The map shows how the wind lines up with each runway; it is not the runway plan, because which runways and which direction are in use is decided by air traffic control (NATS) and depends on the forecast and traffic as well as the surface wind. Runway coordinates are from OurAirports, the base map is © OpenStreetMap contributors (ODbL), and runway names, lengths and usage are from Wikipedia and Heathrow. AeroGaze is an independent site, not affiliated with Heathrow Airport Limited or NATS.
Two, both running east-west and parallel: the northern runway (09L/27R, 3,902 m) and the southern runway (09R/27L, 3,660 m).
That is decided by air traffic control (NATS), not by AeroGaze, so this page doesn't claim to know. In the daytime Heathrow prefers westerly operations unless the tailwind would exceed 5 knots. This page sets today's wind against that number and shows the headwind and crosswind on every runway end.
In westerly operations Heathrow uses one runway for landings and the other for take-offs, and the two swap at 15:00 each day so that communities under the flight paths get respite. In easterly operations the runways do not swap at 15:00. Night flights follow a separate rotation.
The number is the runway's compass heading divided by 10, rounded: 27 is about 270° (flying west) and 09 about 90° (flying east). L and R (left and right) tell the two parallel runways apart. Every runway has two ends with numbers 18 apart, such as 09L and 27R.
From the METAR for Heathrow (EGLL), the standard aviation weather report, via the NOAA Aviation Weather Center. It is issued about every half hour and the report time is shown on the page. Wind directions are true (not magnetic), the same as the runway headings used here.