Llanystumdwy Pressure & Humidity
Gwynedd — Barometric Trends
Llanystumdwy Pressure & Humidity Outlook
For Llanystumdwy today, pressure is around 997 mb, notably low for the season, with humidity running high, so it can feel a bit close at times. That favours a more variable day, with timing and wind making the biggest difference. With a wide spread in values, the background feel can swing between steadier and more mixed spells. The later rise can help conditions calm down in places.
Over the coming days, pressure is likely to sit between 994 mb and 1025 mb in the days ahead. Pressure trends higher through the coming days, favouring quieter spells at times. Humidity looks generally high, which can help low cloud to linger in calmer spells.
Current Readings
Pressure
Humidity
Dew Point
Today’s Hourly Humidity
Today’s Hourly Pressure
14-Day Trends
Humidity Chart
Pressure Chart
Forecast context and reference links
Forecast charts summarise likely conditions, but day-to-day outcomes in the UK often depend on how the larger pressure pattern evolves. Use the context links below to interpret the signal more reliably.
- Wales Climate for regional patterns and seasonal tendencies.
- UK Climate Overview for a national baseline and how regions compare.
- Wales for location browsing and regional navigation.
How to interpret confidence
For how forecast reliability changes with lead time, see Forecast Confidence. For transparency on how WeatherEngland sources and updates data, see Methodology.
Background guides
- UK Weather Patterns
- UK Seasonal Weather
- UK Weather Hazards
- UK Weather Safety
- UK Jet Stream
- UK Microclimates
Glossary support
Start with the Weather Glossary. Useful terms for this page include Isobar, Pressure Gradient, Relative Humidity, Dew Point, Anticyclone, and Depression.
FAQ
What is the air pressure in Llanystumdwy today?
Pressure in Llanystumdwy is close to 997 mb right now. It helps describe the broader set-up, while cloud, fronts and local effects still decide the day-to-day detail. Later in the outlook, pressure trends a little higher, which can bring quieter interludes at times.
What counts as high or low pressure in the UK?
In UK terms, pressure in the low 1020s (around 1020 mb–1024 mb) often supports a steadier background, while the low 1000s (around 1000 mb–1004 mb) more often sits closer to passing low-pressure systems. What matters most is the wider pattern and whether pressure is rising or falling.
How does pressure affect wind in Llanystumdwy?
Pressure influences wind through the regional gradient. When the pattern tightens, winds can pick up; when it relaxes, winds usually ease.
Does low pressure always mean rain in Llanystumdwy?
Not necessarily. Low pressure favours rising motion and cloud development, but rainfall depends on available moisture, frontal features and the track of the system. Some low-pressure days are simply cloudy and breezy with only patchy showers.
What does humidity mean for comfort in Llanystumdwy?
It is the amount of water vapour in the air relative to its capacity at that temperature. When humidity is high, evaporation slows and the air can feel damp; when it is lower, comfort and visibility often improve. Moisture levels stay on the higher side overall, so visibility can drop more easily in calmer spells, with low cloud more prone to linger.