The mum-of-three took to the garden at her London home in an eye-catching blue bikini with white stripes.
WATCH: Holly Willoughby reveals huge error at home
The presenter also took a Panama hat out with her to help protect her from the rays, but it wasn't relaxation that was on Holly's mind.
The 40-year-old had decided that the sunny weather had given her a great opportunity to "make the final edits" to her upcoming memoirs, Reflections.
"Saturdays in the sunshine… it doesn't get any better," she wrote.
"Using the time to make the final edits to my book 'Reflections'… going through the manuscript, adding, clarifying, tweaking… getting it just perfect for you… not too much longer now…"
Fans got incredibly excited for the news that Holly shared, with many commenting that they "can't wait" to read the book when it's released on 28 October.
The star used the good weather to tweak her memoirs
But many also complimented the star's appearance, as one wrote: "You look gorgeous, I'm so excited for your book. I know it's going to be amazing."
Another said: "Stunning always," and a third commented: "Gorgeous. Happy Saturday!"
When Holly announced her book, she said it was her "celebration of how inner and outer beauty can work together in perfect harmony".
Reflections by Holly Willoughby, £16, Amazon
"I hope this book will start conversations, whether they're about how to find your signature lipstick, reclaim your sexuality, or treat yourself more kindly – and, ultimately, what it means to feel beautiful, confident, complete."
The star enjoyed the sunny weather again earlier this week, but she left fans confused after they were convinced that she'd gone to Portugal, despite the government's travel restrictions.
Holly's last sunbathing snap left fans convinced she was in Portugal
Holly took a selfie while out enjoying the sun's rays, and relaxing in the garden at her £3million London property.
She has given several looks inside the beautiful outdoor space over the years, and it features a very large and pristine lawn as well as gorgeous rattan furniture.
The mother-of-three also has an egg-shaped BBQ which she will no doubt use as temperatures are meant to hit 28 degrees over the weekend.
Holly is a fan of holidaying in Portugal, but hasn't travelled there since 2020, and she had to cut her last vacation to the country short in order to quarantine and be able to present This Morning.
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