BBC weather forecast says UK's glorious 'mini-heatwave' to last nine September days

BBC weather forecast says UK's glorious 'mini-heatwave' to last nine September days According to the latest BBC Weather data, the UK is set for an extended run of late-summer warmth, with temperatures forecast to reach 22C or higher across nine consecutive days Britons are poised to experience a sustained late-season spell of sunshine. Temperatures will jump to way above average for the time of year for nine consecutive days later this month, meteorologists understand. The mercury will stay at 22C or above in several regions, according to the most recent BBC Weather projections. High pressure is expected to secure settled, bright weather across southern areas and the Home Counties from Tuesday September 22. Typically in September, the mercury rarely exceeds 20C across the Southeast of England and mid to late teens in northern areas of the UK. "Atlantic weather fronts becoming more confined to northern and northwestern areas. As such, plenty of dry and increasingly warm and perhaps rather humid weather will develop," reads the long-range Met Office forecast. BBC graphics also support the understanding the weather is set to be pleasant. But rain is forecast first, including tonight, and the end of the week is poised to be unsettled for many regions. Downpours are also likely, especially across the Northwest of England, on Friday, forecasters say. Yet the picture quickly changes and what has been dubbed a "mini-heatwave" is on the horizon. Temperatures will rise swiftly from Tuesday, with the East of England and the Southeast of England to bask in the warmest plumes. However, it will be at least 20C as far north as South Yorkshire, it is understood. During the hottest spells, most likely to be mid afternoons next week, the mercury could even each 23C in the Southeast of England. Skies will be clear everywhere and winds will be light, and so it may feel even warmer, meteorologists say. This high pressure will remain for most of the week, and so temperatures will be warmer than the 11.9C and 15.8C, recorded on Tuesday in Lerwick, Scotland and near Carlisle, Cumbria, respectively. But the rain forecast this week is due to be heaviest throughout tonight and into Thursday morning, particularly across northern and western Scotland. Friday's showers will be more widespread though, and strongest during the evening over Lancashire, Cumbria and parts of north Wales. The weekend will be unsettled too as drizzle is expected on Saturday across southern parts of England, including Somerset and Wiltshire, and south Wales. Sunday, however, is drier for many, leading into the warm spell next week. The Environment Agency had, until recently, flood alerts in place over concerns for the rain forecast. It had expressed concern for the Tidal River Avon, on the Somerset coast at Porlock Weir and the tidal River Waveney, where it said high tides were expected.