Monday and Tuesday are both forecast to have clear skies and warm sunshine for most of the day, particularly towards the west of the county.
Temperatures on Monday are set to reach 18 degrees in early afternoon but brightest part of the week is expected to be late afternoon on Tuesday at more than 20 degrees.
Sunny spells will likely continue through Wednesday and Thursday albeit with more overcast skies and cooler temperatures of around 14 and 15 degrees.
Friday is expected to bring similar weather with pockets of sunshine to the north of Sussex in Horsham and Crawley.
The latest forecasts also predict a dry day to enjoy the royal wedding on Saturday, with sunshine towards East Sussex and the coastal areas in the early and late hours of the day.
Street party-goers can expect cloudy skies and temperatures of around 15 degrees across most of Sussex.