Weather remains the perennial wild card for UK energy markets. A colder-than-average Q4 would sharply increase heating demand, both directly through gas consumption and indirectly through power demand, particularly from electrified heating and industrial activity.
At the same time, the UK’s growing dependence on wind generation makes it vulnerable to “dunkelflaute” periods — when cold conditions coincide with very low wind output.
During such spells in recent winters, UK gas burn for power generation has risen sharply, at times nearly 20% higher year-on-year. The forward market always includes a winter premium to reflect this risk, but the scale of any cold/low-wind event determines whether prices spike above base-case ranges.
In a severe, prolonged event lasting several weeks, Q4–25 could see an extra 8–12 p/th added to NBP gas and 10–20 £/MWh to baseload power. Conversely, if weather proves mild and windy, prices could soften toward bear-case levels, especially given Europe’s supportive storage position.
Long-range forecasts from meteorological services currently suggest the UK’s weather for Q4–2025 will be milder than seasonal averages, although uncertainty remains. This could bring a mix of unsettled conditions, including storms, but with an overall tendency for above-average temperatures and slightly higher-than-average wind generation.
