In Summer is an 1868 oil-on-canvas painting by Pierre-Auguste Renoir, a portrait of Lise Tréhot aged about 20. Tréhot was Renoir's companion from about 1866 to 1871. He painted her at least 23 times, including Lise with a parasol, painted in 1867, Renoir's first significant critical success which was admired at the Paris Salon in 1868. This success may have inspired Renoir to paint her again, this time in a more informal style.