Weather for the construction industry.

Weather built for construction, not for choosing a coat

Weather Metric is a free UK weather tool made for people running building sites. A consumer forecast tells you it will rain. A site needs two different answers: what the weather is about to do to the programme, and what it actually did last Tuesday when the pour was called off. This does both, and it is free with no sign-up.

Rainfall measured at a named gauge, not a grid square

Daily rainfall comes from the nearest Environment Agency rain gauge, published under the Open Government Licence. The record names the station and states how far it is from your site. That distinction is the whole point: a gauge measurement is evidence somebody else can check, a model average is an estimate, and the record labels which one you are reading rather than blending them.

Your own limits, checked against the forecast

Set the figures your site actually works to and every breach in the next 48 hours is listed as a window you can act on. Careful-lift and MEWP gust caps, the wind speed that takes the crane out of service, the 5 to 30 degree concrete pour range, mortar below 2 degrees, coatings inside 3 degrees of the dew point, and the rainfall that pulls external trades in. The defaults are common industry figures and every one is editable, because a specific crane has a specific number in its manual and that is the number that matters on the day.

A crane weather app built around your crane’s own limits

If you are looking for the best app for crane weather, look for four things. It should read gusts, not only the mean wind. It should use your crane’s own figures from its manual, not one generic threshold. It should show the hours when a limit is approached or exceeded, not a single number for the day. And it should say how sure the forecast is. Weather Metric does all four, free and with no sign-up, on the web and on iPhone. The Crane view shows the next 48 hours against your out-of-service gust, careful-lift gust and mean wind limit, with the peak gust and the hour it arrives, and the 07:00 brief sends the day against your limits each morning. The figures are forecast at 10 metres, not at jib height, so it is a planning aid: the decision on a lift stays with the appointed person and the crane supervisor.

Free crane wind records, with every source named

The Record tab builds a day-by-day weather record for any UK site and any date range: the mean wind, the strongest wind and the peak gust for each day, with the wind direction, modelled from the historical weather archive and labelled as modelled, next to measured rainfall from the nearest Environment Agency gauge with its distance from site. It downloads as a CSV. When a lift was stood down or a pour was called off, that is a record of what the weather did on the day that the other side can check, rather than a recollection.

Concrete pours, mortar, roofing and coatings

The same limits cover the rest of the site: the 5 to 30 degree concrete pour window, frost and mortar below 2 degrees, the dew-point margin for coatings, and the rainfall that stops external trades. Each is checked hour by hour against the forecast and set to your own figures, so a roofer, a groundworks gang and a crane crew can each read the day against the number that governs their work.

Daylight costed against the shift

Sunrise, sunset and civil twilight are computed for the exact coordinates, along with how many minutes of your working hours fell outside usable light. In December that number is often the argument.

Why a weather record matters on a delay claim

Weather is one of the most argued causes of delay on UK construction projects. Under NEC and JCT contracts, a compensation event or an extension of time turns on contemporaneous evidence. "It rained all week" is an assertion. "The Environment Agency gauge two kilometres from site recorded 26 millimetres that day" is a fact the other side can verify. A weather record captured day by day from named sources is contemporaneous; one reconstructed at submission time is not, and it reads that way to everyone assessing it.

Bring a diary from any product

Export a site diary as a CSV from whatever you already use and drop it in. Every dated row comes back with measured rainfall, the gauge named, modelled conditions, sunrise and sunset, and the minutes of the shift outside usable light. The file is processed in your browser and is never uploaded anywhere.

What it covers

Forecast, radar, daylight and air quality cover the whole United Kingdom. Measured rainfall depends on Environment Agency gauge coverage, which is England, and the record always states the distance to the nearest gauge so you can judge whether it speaks for your site. Live traffic cameras are currently London only, through Transport for London’s open data.

When the record has to become evidence

Weather Metric is free and stops at the record. When that record has to carry a claim, weather evidence for extensions of time in Construction Metric adds the standdown log, daily values with sources and checksums, and the month against the long-term record with a properly calculated one-in-ten return period. Early warning notices drafted from the forecast turn a breach of your own limits into an NEC early warning or a JCT delay notice, marked for review before it goes. Tender weather allowances give the average unsuitable days per trade and month from the long-term record, with the return values kept apart from the averages. All three are built by AI Metric, which builds AI that understands how construction is actually delivered.

Weather Metric is a free side product of Construction Metric, which keeps the whole site record: the WhatsApp photographs, the diaries, the documents and the programme. Read what Weather Metric does, or see the full site diary.

What makes it different

• Five models, one honest number. Every published hour is the mean of the Met Office, ECMWF, NOAA GFS, DWD ICON and Météo-France models for the first days (gusts from the four that publish one; ECMWF does not), then of the longer-range models that still run, with the spread between them shown and each hour saying how many models it rests on, so a confident forecast and a contested one look different. The mix is checked against what UK airport stations and Environment Agency gauges recorded. If the comparison fails to load, the page says it is showing one model instead of pretending otherwise. Expected is the mean; Cautious is the worst credible hour, a stated rule about the spread and never a probability.
• Rules written in construction terms. Crane out-of-service gusts, careful-lift and MEWP caps, the concrete pour window, mortar minimums and dew-point margins for coatings, each set to your own figures and reported as within limits, approached or exceeded, hour by hour.
• Measured, not modelled, where it matters. Rainfall in the record comes from a named Environment Agency gauge with its distance from site stated, so a claim quotes a reading the other side can check.
• Rain to the minute, drone zones and the national map. Next-hour rain by the minute where Apple WeatherKit has it, the Met Office 2 km nowcast for the next hours, NATS drone restriction zones around the site, and a UK overview map for the whole country.
• Nothing to sign up for. Type a postcode and the record loads; export it, or bring a site diary CSV and get the weather appended in the browser.

Guides

• Crane wind speed forecast: When will gusts exceed your crane’s out-of-service and careful-lift figures?
• Construction weather forecast: What will the weather do to your site programme this week?
• Concrete pour weather: When is the temperature outside your 5 to 30 degree pour window?
• Roofing weather forecast: When are wind, rain and dew point outside your roofing and coating limits?
• Construction rainfall records: What did the nearest Environment Agency gauge measure on a given day?
• Weather delay claim evidence: What does a contemporaneous weather record need to contain under NEC and JCT?
• Site diary weather record: How do you attach measured weather to an existing site diary?

Questions people ask

What is the best app for crane weather in the UK?

Look for an app that reads gusts as well as the mean wind, uses your crane’s own figures, shows the hours when a limit is approached or exceeded, and says how sure the forecast is. Weather Metric does all of that for free, on the web and on iPhone, with no sign-up: the Crane view shows the next 48 hours against your out-of-service gust, careful-lift gust and mean wind limit.

Is there a free crane wind speed app?

Yes. Weather Metric is free at www.weather-metric.com and free on the App Store for iPhone. There is no account and no subscription. Set your crane’s limits once and they are saved with the site on your device.

How accurate is the wind forecast for cranes?

Every hour is the mean of up to five national models (the Met Office, ECMWF, NOAA GFS, DWD ICON and Météo-France) for the first days, with gusts from the four that publish them, and the spread between the models is shown, so you can see when the forecast is confident and when it is contested. The Cautious reading takes the worst credible hour across the models. No forecast is exact, and the figures are at 10 metres rather than at jib height, so the spread is how you judge it.

Can I get free wind records for a crane that was stood down?

Yes. The Record tab builds a day-by-day record for any UK site and date range, with the mean wind, the strongest wind, the peak gust and the direction for each day, labelled as modelled, next to measured rainfall from the nearest Environment Agency gauge. It downloads as a CSV, free.

Is there a free weather app for concrete pours?

Yes. Weather Metric checks the forecast against the 5 to 30 degree pour window, frost and the rain that stops a pour, hour by hour, using your own figures. It is free with no sign-up.

What is the best weather app for construction sites?

One that checks the forecast against the limits your site works to rather than showing a general forecast. Weather Metric does that for crane, lifting, MEWP, concrete, mortar, coating and rain limits, keeps a day-by-day record with measured rainfall from named Environment Agency gauges, and is free on the web and on iPhone.

Is Weather Metric free?

Yes, and there is no sign-up. Type a postcode and the record loads. It is free because the weather line belongs in the same place as the rest of a site record, and it shows what Construction Metric does with everything else a site says and photographs.

Where does the rainfall figure come from?

Measured rainfall comes from the nearest Environment Agency rain gauge, under the Open Government Licence, and the record names the station and states its distance from your site. Modelled figures come from open weather-model data and are labelled as modelled. A gauge measurement is checkable evidence; a model average is an estimate, and the record never blends them.

Can weather records be used in a construction delay or extension of time claim?

Weather is one of the most argued causes of delay on UK projects, and under NEC and JCT a compensation event or extension of time turns on contemporaneous evidence. It rained all week is an assertion. The Environment Agency gauge two kilometres from site recorded 26 millimetres that day is a fact the other side can check. A record captured day by day from named sources is contemporaneous; one reconstructed at submission is not.

What are trade threshold alerts?

You set your own working limits, starting from common industry figures: careful-lift and MEWP gust caps, the crane out-of-service wind speed, the 5 to 30 degree concrete pour window, mortar below 2 degrees, coatings within 3 degrees of the dew point, and the rainfall that pulls external trades in. Every breach in the next 48 hours is listed as a time window, so you get Sunday 10:00 to 11:00, gusts to 41 km/h rather than a wall of numbers.

Can I add weather to a site diary kept in another product?

Yes. Export the diary as a CSV from whatever you use and drop it in. Every dated row comes back with measured rainfall, the gauge named, modelled conditions, sunrise and sunset, and the minutes of the shift outside usable light. The file is processed in your browser and is never uploaded.

Does it cover the whole of the UK?

Forecast, radar, daylight and air quality cover the whole UK. Measured rainfall depends on Environment Agency gauge coverage, which is England, and the record says how far the nearest gauge is so you can judge it. Live traffic cameras are currently London only, through Transport for London open data.