Onllwyn Pressure & Humidity
Neath Port Talbot — Barometric Trends
Onllwyn Pressure & Humidity Outlook
Across Onllwyn today, the barometer is near 995 mb, well on the low side, with high humidity making it feel rather clammy in sheltered spots. That raises the chance of a more changeable spell at times, even with quieter windows in between. With a wide spread in values, the background feel can swing between steadier and more mixed spells. Later on, the balance can tip a touch more settled at times.
Over the coming days, pressure is likely to sit between 996 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
For Onllwyn, the forecast is best read as a combination of short-range detail and broader regime. The first few days carry the highest timing confidence, while later periods describe direction and pattern.
- 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 Onllwyn today?
Atmospheric pressure in Onllwyn is currently around 995 mb. It gives a sense of the overall pattern, though the local detail still comes down to cloud cover and wind. Humidity is near 94%, so the air is close to saturation — conditions where low cloud or reduced visibility can become more likely if winds ease, especially overnight. As the period goes on, the barometer tends to lift, supporting a more settled background pattern at times.
What counts as high or low pressure in the UK?
As a rough guide, the low 1020s (around 1020 mb–1024 mb) tends to be a more settled signal, while the low 1000s (around 1000 mb–1004 mb) more often points to Atlantic influence. The overall pattern matters more than any single reading.
How does pressure affect wind in Onllwyn?
Wind strength is driven mainly by the pressure gradient — how quickly pressure changes over distance. Tightly packed isobars usually mean stronger winds; a slack pattern often allows lighter winds, regardless of whether the headline pressure is high or low.
Does low pressure always mean rain in Onllwyn?
No. Low pressure increases the chance of changeable weather, but the wettest rain bands can miss your area entirely depending on where fronts set up.
What does humidity mean for comfort in Onllwyn?
It reflects how much moisture the air is holding compared with its maximum. Higher values can favour haze or low cloud, especially when winds are light. Humidity is frequently elevated through the period, which can keep the air feeling damp and occasionally reduce visibility in lighter winds.