Observations

Everything the Meteorological Office of the Velocity Interoperability Network does begins with observation. Twelve stations, two weather radars, an upper-air station and three coastal gauges measure the weather of the Network continuously, and their observations are the basis of every forecast, every warning and every entry in the climate record.

Observations are made to a common programme at every station so that readings from different sites and different years can be compared. The programme was adopted during the transition period, between 10 August and 5 September 2026, when the stations were transferred to the Office from the member organisations that had operated them.

288

Surface observations recorded across the Network every day

576

Radar scans each day from the two weather radars

30 km

Height reached by the twice-daily sounding balloon from Central Exchange

3

Staffed stations at which an observer supplements the automatic record

What is observed. The elements below are measured across the network. Not every element is measured at every station; the register on the Stations page shows the programme at each.

Air temperature and humidity

Measured at every station in a ventilated screen 1.25 metres above the ground, reported hourly, with the highest and lowest temperature of each day recorded at 09:00.

Atmospheric pressure

Measured by a barometer at every station and reduced to mean sea level so that readings from stations at different heights can be compared. The pressure tendency over the past three hours is reported with it.

Wind

Speed and direction measured ten metres above open ground. The mean over the ten minutes before the hour and the highest gust of the hour are both reported; the highest gust of the day is recorded separately.

Rainfall

Measured continuously by a tipping-bucket gauge at every station and totalled hourly. At the staffed stations a storage gauge is read at 09:00 as a check on the automatic record.

Visibility and present weather

Measured by sensor at every station and by the observer at the three staffed stations, who reports the weather occurring at the time of observation and during the past hour.

Cloud

Amount, type and base height. Base height is measured by ceilometer at Central Exchange, Northgate Relay and Southbank Terminal; amount and type are reported by the observers at those stations.

Sunshine and solar radiation

Measured continuously at Central Exchange, Eastfield Campus and Ridgeway Summit and totalled hourly.

Sea state and water level

Wave height and period and the level of the sea against predicted high water, measured every ten minutes at Southbank Terminal, Harbour Head and Saltmarsh.

Upper air

Temperature, humidity, pressure and wind measured by a radiosonde carried by balloon from Central Exchange at 00:00 and 12:00 to a height of about thirty kilometres.

Precipitation by radar

The location, intensity and movement of rain, snow and hail across the Network, scanned every five minutes by the radars at Harbour Head and Ridgeway Summit to a range of 150 kilometres.

Soil temperature and state of ground

Soil temperature at 10 and 30 centimetres, and whether the ground is dry, wet, frozen or snow-covered, recorded at the staffed stations at 09:00.

The observing programme. Observations are made at the times and frequencies below. All times are those of the Network.

Quality control. Every observation is checked automatically as it is received for range, for consistency with the station's previous readings and for agreement with neighbouring stations. Readings that fail a check are flagged and examined by an observer before they enter the climate record. Instruments are inspected monthly and calibrated against reference instruments held at Central Exchange at least once a year. Observations are marked provisional until they have passed through these checks, which is normally within ten days.

Reports from the public. The Office welcomes reports of notable weather from citizens of the Network: the size of hail, the depth of snow, damage caused by wind, flooding and the like. Reports with the place, the time and, where possible, a measurement may be sent to contact@meteorology.gov.vin. They are used to verify warnings and are acknowledged in the monthly climate summary.

Obtaining observation data. Observations are available to member organisations, to citizens and to researchers on request.

1. 1

   Step 1: Identify what you need

   Decide which station or stations, which elements, what period and what frequency you require. The register of stations and the observing programme above show what is available.

2. 2

   Step 2: Write to the Office

   Send your request to the Office's email address, stating the purpose for which the data is required. Data is supplied without charge to member organisations and citizens of the Network for their own use; requests for reuse in a published or commercial product are considered individually.

3. 3

   Step 3: Receive the data

   Data is supplied by email as a plain text file, normally within five working days. Observations not yet through quality control are marked as provisional.

4. 4

   Step 4: Acknowledge the source

   Data reproduced elsewhere should be acknowledged as observations of the Meteorological Office of the Velocity Interoperability Network, with the date of supply.

For the forecasts made from these observations, see Forecasts; for the summaries compiled from them, see Climate Records; for answers to common questions, see the frequently asked questions.