Full Breakdown
Heat Dome Weakens: Met Office Forecasts Final Warm Spell Followed by Changeable Autumn Weather
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Background & Context
A high-pressure “heat dome” over western Europe in early September pushed temperatures above 40 °C in parts of Spain and Portugal. The Met Office explained that sinking air compresses and warms, suppressing clouds and producing dry, hot conditions. By mid-September the dome began to dissipate, allowing cooler maritime air to move northward. The agency now expects the lingering warmth to give way to a more typical early-autumn pattern across the United Kingdom and Wales.
Core Forecast Overview
The Met Office warned that a deep low-pressure area developing over the Atlantic will draw warmer air from the continent and subtropical Atlantic, leading to “predominantly dry and bright conditions” later in the week. Temperatures could reach the upper 20s °C by the end of next week, offering “a final taste of summer.” A colder front from the west may arrive later, making conditions “changeable” with intermittent rain and a return to near-normal temperatures.
Detailed Day-by-Day Outlook
- Friday, September 18 – Clear start, 11 °C early, rising to about 18 °C by early afternoon. Light rain chance of <5 % after 9 p.m., with overnight lows near 15–16 °C.
- Saturday, September 19 – Partly cloudy, morning temps near 16 °C and afternoon highs 18–20 °C. Rain chances 5–10 %, occasional sunny intervals. Oldham gusts up to 35 mph, feeling closer to 15 °C.
- Sunday, September 20 – Partly cloudy early, clearing by mid-morning. Temps climb from 11 °C to a peak of 21 °C; rain probability under 5 %. Evening clouds increase, modest rain chance (~30 %) in Oldham.
- Monday, September 21 – Partly cloudy, warm spell; temps start near 17 °C and rise to 24 °C in many locations. Sunny intervals likely from early afternoon. Wales: highs of 21 °C in Cardiff, up to 23 °C in Wrexham, Abergavenny and Hay-on-Wye.
- Saturday, September 26 – South Wales peak 17 °C; north Wales highs around 16 °C.
- September 22 – October 1 – Long-range outlook anticipates a build of high pressure across much of the UK, with Atlantic fronts confined to the far northwest.
Why It Matters
The brief return to upper-20s °C offers a final opportunity for outdoor events and reduces immediate heat-related health risks. The shift to changeable weather and stronger winds—particularly the 35 mph gusts expected in parts of the North West—poses challenges for agriculture, travel and flood-risk management as the country moves toward autumn.
Conflicting Reports & Gaps
Local forecasts are broadly consistent, all citing clear to partly cloudy conditions, modest temperature rises and low rain probabilities for the weekend. The only notable variation is the specific wind-gust estimate for Oldham versus generally breezy conditions elsewhere. No substantive contradictions or missing data were identified.