The Met Office is warning of rain in the SW, including Cornwall and Devon.
Areas of persistent and sometimes heavy rain may lead to localised flooding and travel disruption.
Timing is listed as between 14:00 on Sun 27 Jun 2021 and 07:00 on Mon 28 Jun 2021.
More detail: persistent rain, heavy and possibly thundery at times, will move across southern and southwestern areas of England and parts of south Wales through Sunday afternoon, persisting into Monday morning, before easing. 20-40 mm is likely to fall quite widely across the area but a few places could see 60-80 mm over this period, including 15-25 mm within an hour.
Such totals may cause travel disruption and some flooding.