Met Office officials have this lunchtime issued a severe weather warning for the region.
Severe gales are expected to develop across much of the country for a time tonight.
Inland gusts may locally exceed 60mph close to the squally cold front, whilst gusts of 60 to 70mph seem likely at coastal sites in the south and west, as well as across hills.
Gusts may exceed 75 mph in the more exposed coastal locations.
“The public should be aware of the risk of disruption to transport and possibly power supplies,” said a spokesman.
The previous warning covering much of the UK has been split; this warning for southern Britain is restricted to the overnight period, with the risk receding eastwards by morning.
Another deep Atlantic low pressure system will approach northern Britain tonight and into Thursday.
Across most of southern Britain, the strongest winds are expected from late evening through the nighttime period, particularly on and just ahead of a squally cold front, which will move east with time.
“As this continues eastwards, so the strongest of the winds should ease later,” added weather experts.
“As well as the very strong winds, a band of squally rain is likely to sweep eastwards across many parts through the period.”