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Live forecasts update automatically; written guidance last reviewed 13 June 2026 by the Insight Britain weather desk. Data from national met services via Open-Meteo.
Surface pressure charts show the atmospheric pressure across the UK and surrounding seas, helping you forecast wind, rain, and settled weather. By reading the isobars, high and low pressure systems, and weather fronts, you can understand what conditions are heading your way over the coming days.
What exactly is a surface pressure chart?
A surface pressure chart, also known as a synoptic chart, is a map that displays atmospheric pressure at sea level. The Met Office and other weather services produce these charts to show the current state of the atmosphere and to predict how it will change. They are the foundation of most weather forecasts you see on television or online.
How do I read the lines on a pressure chart?
The curved lines you see are called isobars. Each isobar connects points of equal atmospheric pressure, measured in millibars. The closer together the isobars are, the stronger the wind will be in that area. Widely spaced isobars indicate light winds and generally calm conditions.
Isobars form roughly circular patterns around areas of high pressure (anticyclones) and low pressure (depressions). In the UK, high pressure usually brings settled, dry weather, while low pressure is associated with cloud, rain, and stronger winds.
What do the H and L symbols mean?
An “H” marks the centre of a high-pressure system. Air descends here, inhibiting cloud formation, so skies tend to be clear or partly cloudy. An “L” marks a low-pressure system, where air rises, cools, and condenses into clouds and rain. The pressure gradient between these systems drives our weather patterns across the Atlantic.
Understanding weather fronts on the charts
Weather fronts are shown as coloured lines with symbols. A blue line with triangles indicates a cold front, where colder air pushes under warmer air, often bringing heavy rain followed by clearer conditions. A red line with semicircles marks a warm front, where warm air rises over cold air, producing prolonged, steady rain. An occluded front, shown as a purple line with alternating triangles and semicircles, forms when a cold front catches up with a warm front, often bringing complex weather.
How do surface pressure charts help with wind forecasts?
The spacing of isobars directly tells you about wind strength. Tightly packed isobars mean a steep pressure gradient and strong winds. Widely spaced isobars mean a gentle gradient and light winds. Wind direction is also indicated: in the northern hemisphere, wind flows anticlockwise around a low and clockwise around a high, roughly parallel to the isobars.
Where can I find reliable surface pressure charts?
The Met Office provides free surface pressure charts for the UK and Europe, including 7-day and 10-day outlooks. Many independent weather sites also offer 14 day Atlantic pressure charts and 10 day pressure charts UK, which are useful for planning ahead. For a quick overview, you can check the 10-day forecast on our site, which is based on these same charts. For more detail, the UK weather hub links to the latest analysis and forecast charts.
What is the difference between a 7-day and a 14-day chart?
A 7 day surface pressure chart shows the forecast for the week ahead and is generally more reliable. A 14 day Atlantic pressure chart gives a longer-range view, useful for spotting broad trends, but confidence in the exact position of fronts and lows decreases after about day seven. Many forecasters offer 14 day Atlantic pressure charts free of charge, though they should be treated as guidance rather than a precise forecast.
How do pressure charts relate to weather warnings?
When a deep low-pressure system is forecast, with tightly packed isobars indicating gale-force winds, the Met Office may issue a weather warning. You can check the latest UK Weather Warnings on our site to see if any alerts are in force for your area. Similarly, prolonged high pressure in winter can lead to cold snaps that trigger Cold Weather Payments.
Can I use these charts to plan outdoor activities?
Yes. If you see a large area of high pressure over the UK on a surface pressure chart Europe view, you can expect a few days of dry, settled weather. If a low is approaching from the Atlantic, with fronts sweeping across the country, plan for rain and wind. For a quick summary of conditions, the live forecast above gives you the current situation, while the charts help you see what is coming.
What do the numbers on the isobars mean?
The numbers represent atmospheric pressure in millibars. Typical values around the UK range from about 960 mb (very deep low) to 1040 mb (strong high). The standard average sea-level pressure is 1013 mb. Numbers above this indicate high pressure; numbers below indicate low pressure.
Are Met Office surface pressure charts free to use?
Yes, the Met Office provides met office surface pressure charts free of charge on its website. They offer analysis charts for the current conditions and forecast charts for up to seven days ahead. Many other weather services also provide free access to similar charts for the UK and Europe.
How often are surface pressure charts updated?
The Met Office updates its analysis charts every six hours, based on observations at 00:00, 06:00, 12:00, and 18:00 UTC. Forecast charts are typically issued twice daily. For the most up-to-date view, always check the timestamp on the chart you are using.
What is the difference between a surface chart and an upper air chart?
A surface chart shows conditions at sea level, including pressure, fronts, and wind near the ground. An upper air chart shows pressure and wind at higher altitudes, such as 500 mb (around 5,500 metres). Upper air charts help forecasters understand the steering currents that move weather systems.
For a deeper understanding of how we produce our forecasts and where our data comes from, please see our Sources & Standards page.