A warm Carribean blast will send temperatures soaring in London for a brief period
September’s wild month of weather is set to continue with temperatures soaring to 26C this week. From Wednesday, September 17 the mercury will steadily rise from 20C to 23C the following day before peaking at 26C on Friday, according to the Met Office.
This will be the crescendo of London’s short-lived ‘Indian summer’ before a dramatic shift into more autumnal conditions, with the mercury plunging to 16C by Monday, September 22. Long-range weather forecasts predict temperatures will then remain below average for the remainder of the month, although there could be some slightly warmer periods of sunshine.
Weather maps from WXCharts show the surge in temperatures is due to the jet stream bringing a brief surge of warm air from the Caribbean and southern US. But after this dies down weather fronts from the North Atlantic Ocean become more influential, resulting in the mercury plunging.
When will it reach 26C in London?
Temperatures will gradually rise from Thursday afternoon onwards as heavy cloud is replaced by sunshine from roughly 1pm. It will peak at 23C ahead of warmer conditions the next day.
Sunny weather is expected all day on Friday, with the warmest conditions of between 25C and 26C expected between 2pm and 5pm before gradually dipping throughout the evening.
Saturday will also bring seasonably warm weather with sun and 20C highs, while Sunday will be dominated by cloud as the mercury drops to 17C
What’s the picture for the rest of September?
More unsettled conditions are expected for the rest of September, although we could experience some drier and sunnier weather before the end of the month.
The Met Office long-range forecast reads: “It is likely to be fairly unsettled at first, with areas of rain or showers, most widespread across central, southern and eastern areas, perhaps accompanied by some strong winds. Into next week, a northwest-southeast split is most likely, with some further rain or showers in southern and eastern areas, closest to an area of low pressure, whilst the best chance of longer, drier spells will be towards the north and northwest, where some patchy fog and rural frost are possible.
“It will also turn colder, as a northerly flow becomes established for a time. Later in the period, more widely drier and settled conditions could develop as high pressure becomes slightly more influential, although probably still with a few coastal showers. Temperatures should gradually return closer to average.”
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