Weathermen say wind and rain are set to blow away the Portsmouth area’s sunny spell.
Gusts of around 60mph are expected along exposed coastlines with the South East forecast to be among the worst affected areas.
Campers and those hoping to enjoy their weekend outdoors have been warned to be careful amid “unseasonably strong” winds, and travellers are being warned of possible disruption to transport.
The conditions are expected to be accompanied by “heavy, blustery showers”, the Met Office said.
The forecaster has issued a yellow weather warning for southern parts of Wales, the West Midlands, the South East, South West and east of England, as winds inland are expected to reach 45mph.
Temperatures are expected to drop from a high of 28C earlier this week to the low 20s or high teens in many parts.
Cornwall Council said emergency services officers will be on standby in case of problems including fallen trees and overturned vehicles.
Meteorologist Helen Roberts said: “It will feel quite chilly and noticeably cooler - there will be a noticeable change for just about everyone.”
Winds will peak on Saturday, with Sunday expected to see more settled conditions.
Ms Roberts added: “Winds will ease off but it will still be breezy, a bit wet and quite blustery in some places.”
The Met office forecast for the south-east is:-
‘A cloudy start today, with outbreaks of rain soon moving into western parts and spreading east during the morning. These easing away from the southwest later, with a few evening brighter spells possible. Feeling cooler than recently, and rather breezy. Maximum Temperature 22 °C.
‘Tonight: Friday’s rain will soon ease away northeastwards, with clearer skies following. although very isolated showers will remain possible. It will also stay rather breezy, especially along the south coast. Minimum Temperature 13 °C.
‘Saturday: Many parts starting dry although a few early showers are likely. These becoming more widespread later, and perhaps heavy at times, although there will also be some warm sunny spells Maximum Temperature 22 °C.
‘Outlook for Sunday to Tuesday: Breezy, with heavy showers Sunday. Winds easing Monday, but rather cloudy with further outbreaks of rain likely. Cloudy at first Tuesday, but also turning drier, more humid, and possibly warmer.’