Overview
- Short‑range forecasts show southern England warming into the mid‑20s with London expected to reach about 25°C on Monday.
- The Met Office says those temperatures are transient and do not meet its heatwave rule which requires region‑specific thresholds to be exceeded for three consecutive days.
- Some forecasting models hint at a possible late‑September surge with spots up to about 30°C and as many as 20 counties reaching 28°C or more but forecasters rate that signal as low confidence and still developing.
- Long‑range guidance for 16 September–10 October points to a changeable pattern with northern and western areas facing more rain and wind while southern England may see drier, warmer spells, and seasonal forecasts raise the chance of a wetter‑than‑average autumn partly linked to El Niño.
- The outlook sits against a provisional record‑warm summer (mean June–August about 16.5°C) and lingering drought impacts, so short spells of warmth are unlikely to trigger heat alerts but could heighten public concern and increase the need to monitor late‑September and autumn flood risks.