The UK land observation network: Underpinning weather and climate understanding

The UK land observation network is a vital part of the nation’s meteorological infrastructure, which continuously captures data essential for weather forecasting, climate monitoring, and environmental management. This article explores the structure, function, and significance of the UK land observation network, which underpins the accurate, timely and trusted Met Office weather forecasts and climate data.

Synoptic observations: The heart of weather monitoring

At the core of the UK land observation network are synoptic stations. These stations are primarily tasked with collecting information about the present state of the atmosphere, which is essential for producing accurate weather forecasts. Synoptic observations provide comprehensive and frequent/regular measurements across a wide range of meteorological variables such as temperature, precipitation and wind.

However, synoptic stations are not the only contributors to the UK’s observational capacity. A variety of supplementary stations support specific requirements, such as long-term climate monitoring, site-specific temperature and wind measurements for customers, and a dense rainfall network critical for water management and flood forecasting. Together, these stations ensure the UK observation network meets both operational and scientific demands across sectors.

Distribution of stations: Ensuring comprehensive coverage

The UK’s synoptic stations are strategically distributed to provide near-uniform coverage across the country. With an average spacing of about 40 kilometres, the layout 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 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.

READ MORE: How the Met Office uses radar to deliver accurate weather observations and forecasts

Site selection: Minimising local influences

Accurate weather and climate observations depend heavily on where stations are located. To ensure data is representative of the broader region’s conditions, station siting follows strict criteria. The ideal location is level ground, free from nearby trees, buildings, or steep terrain that could influence measurements.

Local features can affect measurements: buildings may cause artificial warming, trees can block wind and sunlight, frost hollows may result in low overnight readings and wind measurements taken atop hills or escarpments may not reflect conditions in the broader region.

The Met Office does everything it can to avoid these influences on the UK land observation network in order to ensures its data remains consistent, reliable, and suitable for both operational forecasting and long-term climate monitoring.

What is measured?

With some exceptions, the synoptic stations across the UK measure a number of meteorological elements. These include:

• Air temperature at 1.25 metres above ground, and within a Stevenson Screen
• Air temperature over grass and concrete surfaces
• Soil temperature at depths of 0.1, 0.3, and 1.0 metres
• Relative humidity at 1.25 metres above ground
• Precipitation amount
• Depth of lying snow
• Mean wind speed, direction, and maximum gust at 10 metres above ground
• Atmospheric pressure at station level and reduced to mean sea level
• Pressure tendency and characteristic
• Visibility and present weather
• Cloud amount and type (as identified by an observer)
• Height of cloud base

This comprehensive suite of measurements provides a detailed picture of atmospheric conditions, supporting everything from daily weather forecasts to long-term climate studies.

READ MORE: Seeing the bigger picture: How satellite data shapes Met Office forecasts

Automation and data processing: modernising observation

While we still have 140 manual stations in the Voluntary Climate Network, most meteorological measurements across the UK land observation network are fully automated. Each station continuously logs data, processes it into standard meteorological formats, and transmits it to a central system at the Met Office’s headquarters in Exeter. Each automatic weather station produces data at minute intervals, resulting in a vast high-resolution database that supports operational forecasting and research.

While this high-frequency data is invaluable for research and scientific analysis, it can be too detailed for many practical applications. For synoptic purposes and international data exchange, automatic coded observations are standardised to hourly intervals.. Each automatic weather station reports 24 observations per day, on the hour, which are encoded in internationally agreed formats and shared in real time with users around the world.  

Maintaining quality and safety

Despite the widespread use of automation, some synoptic stations, particularly those at airfields, still rely on trained meteorological observers for key tasks. Aviation authorities require manual oversight of elements critical to aircraft safety, such as cloud, visibility, wind, present weather, and pressure.

Human observers can assess elements that are difficult to automate, including visibility, cloud type, cloud amount, and state of ground. For example, there are currently no sensors capable of identifying cloud type or detecting ground conditions. The human element thus remains an essential part of the network, ensuring that data quality and safety standards are maintained where it matters most.

Supplementary networks: Meeting specialised needs

In addition to the main synoptic network, a range of supplementary stations provide targeted data for specific applications. Climate stations, for example, may focus on long-term temperature and precipitation trends, supporting climate monitoring and research.

Customer-specific sites deliver bespoke measurements such as temperature or wind data. While the dense rainfall network is particularly important for our partners for their water resource management and flood forecasting, offering high-resolution data that supports both operational decision-making and public safety.

READ MORE: How does the Met Office work with the energy sector?

Data management and accessibility

The extensive data and metadata database at Exeter is accessible to researchers, forecasters, and decision-makers, supporting a wide range of meteorological and environmental applications. 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.

The UK land observation network is a cornerstone of the nation’s meteorological capability. Through its carefully distributed synoptic stations, rigorous site selection, comprehensive measurement suite, and integration of automation and human expertise, the network delivers the high-quality data necessary for accurate weather forecasting, climate monitoring, and environmental management.

As technology evolves and the demands on meteorological data increase, the UK land observation network continues to adapt, maintaining its role as a trusted source of information for the public, industry, and government. Whether it is supporting daily forecasts, informing climate policy, or safeguarding aviation, the network’s contribution is both enduring and indispensable.

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