Holiday searches for June on the Thomson website were up by almost 20% on the same month last year.
The operator saw a strong weekend of bookings to top off the month of high demand.
The Balearics, mainland Spain, Greece, Tunisia and Morocco have proved the most popular destinations.
Head of online marketing Nathan Timmins said: “The constant rain is driving all of us around the bend, so it’s no wonder that so many people are looking to head off to get some sunshine.
“As the Mediterranean enjoys temperatures in the late 20s and early 30s we’ve barely seen any sunshine this summer.
“With rain forecast for the rest of the week we imagine that the website will keep attracting more users, as people look to research and book their holidays or just get some inspiration and take their mind off the rain.”