Most investigations of plant responses to changes in temperature have focused on a constant increase in temperature. However, changes in fluctuation in temperature, even if the mean temperature is the same, may affect plant growth. In a new article published in AoB PLANTS, Cerasoli et al. tested the effects of weekly warm and then cool moderate (5oC) and large (10oC) fluctuation in temperature (with the same biweekly temperature sum) on plant growth. They found that, while the ratio of photosynthesis to respiration did not change, fluctuations in temperature did increase biomass accumulation and alter biomass allocation. Their findings suggest that, like mean temperature, fluctuation in temperature can significantly impact plant growth.