Wind check for lifting

Cranes are designed and winded off on the 3-second gust, not the average wind in a forecast. Gusts can be well above the mean, especially at mid-range wind speeds, so the colours on this page always follow the gust.

The Met Office forecasts the wind 10m above the ground, and that is what you see first. The wind is usually stronger higher up, and a crane’s wind limit applies at the boom or jib tip, where its anemometer is (a MEWP’s applies at the platform). When you choose what you are lifting with and set its height, the figures are scaled up to that height, and the switch on the chosen day shows the original Met Office figures. “About this forecast” explains the scaling and where it comes from.

They are cautious planning figures from published guidance and makers’ charts: CPA guidance CIG/TCIG 2507 for mobile and crawler cranes, Liebherr and Spierings load charts for mobile tower cranes, BS 7121-5 for tower cranes and BS EN 280 for MEWPs. Always use the figure for your machine and its set-up from its load chart or manual, and change the preset to match. The full list is in “About this forecast”.

Large, light loads such as cladding, glazing, pods and site cabins catch more wind than a crane is designed for, so they need a lower wind limit. Enter the weight on the hook, the largest face and the shape, and the tool works out a limit for the load using the method in BS 7121-1 and CPA guidance, then marks the forecast against it. It is a planning estimate: the appointed person confirms the limit in the lift plan.

A lightning bolt means a chance of lightning of 5% or more; cranes should stop in thunderstorms. A drop means rain or snow is likely (50% or more, or any snow). Lines mean fog, with visibility under 1km. A snowflake means a frost or ice risk (2°C or colder, or feeling like 0°C or below). The lightning chance comes in 3-hour blocks.

Seven days. The first two days are hour by hour, then the Met Office gives 3-hour blocks. We fetch a fresh forecast at most every 30 minutes, and the time the Met Office issued it is shown under the place name. The further ahead, the less certain the forecast, so check again nearer the day.

Yes. Share (on phones and some browsers), Copy link and Email send a link that opens the same place, settings and day. PDF report makes a report with a QR code to the live forecast. The calendar reminder adds the day to your calendar with an alert three days before, while the job can still be moved.

No. A forecast covers a wide area and your site can differ: buildings can funnel wind, and open or coastal sites catch more. The appointed person sets the limit in the lift plan, and the crane operator makes the final call using the crane’s anemometer.