The Met Office has issued a yellow warning for rain, from midnight to 9pm on Thursday, December 18.
Forecasters say there will likely be “heavy rain” that may cause disruption to travel.
The Met Office added that flooding is possible due to this.
Met Office forecasts heavy rain and flooding in Sussex
The Met Office says: “Some heavy rain will affect southern counties of England during Thursday, perhaps causing some disruption to travel, along with the possibility of some flooding.
“Widely, 15-25 mm is likely across the warning area, but 40-60 mm may fall in some places, most likely over the Downs.
“Rain will clear to the east by the end of the day.
“Strong winds, perhaps gusting in excess of 50 mph in some exposed coastal areas, will accompany the rain, perhaps exacerbating the impacts in a few places.”
The Met Office added that bus and train services will “probably be affected”, with journey times taking longer, and that “some interruption to power supplies and other services is likely”.
Yellow warning of rain affecting London & South East England https://t.co/mWOu2yw1nv pic.twitter.com/41UI3VNLYO
— Met Office – SE England (@metofficeSEEng) December 16, 2025
The forecaster has urged people to check if their property could be at risk of flooding and if so, consider preparing a flood plan and an emergency flood kit.
It also advises avoiding delays by checking road conditions if driving, or bus and train timetables, and amending your travel plans if necessary.
What is a yellow weather warning?
As explained on the Met Office website , weather warnings are issued “when severe weather has the potential to bring impacts to the UK”.
Warnings are given a colour, either yellow, amber or red, depending on a “combination of both the impact the weather may have and the likelihood of those impacts occurring”.
The Met Office explains: “Yellow and Amber warnings represent a range of impact levels and likelihoods.
“This means it is important to read each warning to know what level of impact you can expect for your chosen warning area – and how likely those impacts are to occur.”
For the weather warning for Sussex on Thursday, the warning has a medium likelihood and a low impact.
For a yellow warning specifically, the Met Office says these are typically issued “when it is likely that the weather will cause some low-level impacts, including some disruption to travel in a few places”.
It adds: “Many people may be able to continue with their daily routine, but there will be some that will be directly impacted and so it is important to assess if you could be affected.
“Other yellow warnings are issued when the weather could bring much more severe impacts to the majority of people but the certainty of those impacts occurring is much lower.”
Read more here: Click Here
