Sagebrush ecosystems cover vast areas of the West and are home to many species of conservation concern. Unfortunately, distribution models predict that the total area suitable for sagebrush could be greatly reduced over the next 100 years due to global warming. However, these predictions are based on correlation, not causation. Stronger evidence that above average temperature can actually cause sagebrush cover to change at short timescales would strengthen our confidence in these predictions. We used population models to test how annual temperature variation affected sagebrush cover at 944 monitoring sites across its range. We found that sagebrush cover decreased with above average temperature at hotter sites and increased with above average temperatures at colder sites. This response largely agrees with the predictions made by distribution models and should increase our confidence that the distribution of sagebrush will change in response to climate change in the near future.