Weather observations are on everyone’s mind at the moment, with provisional May daily maximum and minimum air temperature records already reported and further warmth on the way.
New national records undergo a rigorous validation process before a decision is made on officially inducting the figure into the meteorological record books.
This process will include a site inspection and a verification check of the equipment used to measure the temperature.
In order for a value to be treated as an official national record, the Met Office follows national and international best practice and guidance. If the equipment and set-up doesn’t meet the required standards, it will be rejected as an official national record.
But how does the UK land surface observation network actually operate? How do we know the figures are reliable? Here, we explore the UK’s land surface observations network to get you behind the scenes on just one of the ways we monitor the UK’s weather.
Observing the weather
First, it’s important to understand the land-based observations are just one part of the data collection that is undertaken at the Met Office. Satellites, ocean buoys, airplanes and weather balloons all contribute to a rich tapestry of data that observes the UK’s weather and helps inform the complex calculations undertaken on the Met Office supercomputer to help develop the weather forecast.
Weather stations
At the core of the UK land surface observation network are weather stations. These stations are primarily tasked with collecting information about the present state of the atmosphere, which is essential for producing accurate weather forecasts. These observations provide comprehensive and frequent measurements across a wide range of meteorological variables such as temperature, precipitation and wind.
Stations meet varying needs across the UK, such as long-term climate monitoring, site-specific temperature and wind measurements for customers, and a dense rainfall network – which includes data from third-party sources - critical for water management and flood forecasting. Together, these stations ensure the UK observation network meets both operational and scientific demands across sectors.
Comprehensive UK coverage
Weather stations are strategically distributed across the UK, aiming to provide near-uniform coverage where possible. The network is designed to capture key features, such as the weather associated with typical low-pressure systems and frontal activity that frequently influence the UK.
Despite this density, some weather phenomena, such as thunderstorms, occur on smaller scales and may evade detection by the land surface network. To bridge these gaps, satellite and weather radar technologies play a crucial remote sensing role, complementing land-based observations and enhancing the overall spatial resolution of meteorological data and provide a more complete picture of atmospheric conditions.
Choosing where sites are located
Station locations follow strict criteria to ensure data is as consistent and reliable as possible. The ideal location is level ground, free from nearby trees, buildings, or steep terrain that could influence measurements.
Steps are taken to balance the need for observations from a wide variety of locations – such as in cities – with the need for observations that can be as representative as possible of a wider area. For example, frost hollows could result in low overnight readings while windspeeds from on top of hills may not reflect wider conditions.
The Met Office takes steps to avoid these influences on the land observation network to ensure the data is suitable for operational weather forecasting as well as long-term climate monitoring.
Monitoring the data
The Met Office’s commitment to data quality, standardisation, and accessibility ensures that the UK land observation network remains a world-class resource for weather and climate science, and is recognised by the World Meteorological Organization.
In addition to the rigorous standards for the land surface observations network, data is monitored as it is collected, helping to highlight any potential issues on the ground. If data is thought to be suspect, it will be investigated and, if necessary, removed from ongoing official reporting.
Find out more about how the weather is observed.
Find out more about weather stations and how they work.
