U.S. wind power output reaches its peak in March-April and lowest in July-August

Nationally, between January 2016 and August 2022, wind farm capacity factors peaked in March and April and reached minimums in July and August, according to the U.S. Energy Information Administration. The performance of a power plant is often characterized as a percentage of the maximum possible power generation for a given period of time, a measure known as the capacity factor.

Unlike fossil fuel power plants, such as coal or natural gas plants, wind power plants have no operating costs of fuel to generate electricity, and their power generation is entirely dependent on the available wind resources. The performance of a wind power plant is influenced not only by wind speed, but also by wind direction, wind constancy and turbine height. Because of geographic differences in wind resource potential, wind power generation varies in different regions of the United States.

The Lower Plains states, including Texas, Oklahoma, Kansas and New Mexico, account for the largest share of U.S. wind power generation, at 44% as of August 2022. Due to the concentration of wind generation in the Lower Plains, the wind performance pattern is very similar to the seasonal wind performance pattern in the Lower Plains: wind output peaks in spring, declines in summer, and rises again in autumn and winter. While the Upper Plains region has the second-largest share of wind capacity in the U.S. (29%), the Upper Plains also generally follow a similar seasonal pattern to the Lower Plains. The Eastern Interior (13 percent) followed the same pattern, but with larger summer declines than the Upper and Lower Plains.

The seasonal pattern is quite different in the West Coast region (10% of U.S. wind capacity), which is largely influenced by the concentration of wind capacity in California. Wind coefficients on the West Coast rise in late spring, peak in summer, and then decline steadily in fall and winter. The pattern is caused by the interaction of cold air from the Pacific Ocean Current with sea breezes and the location of California wind farms, which are often located near mountain passes near the coast.

In the Southwest, East Coast, and New England regions, wind capacity factors are slightly lower than the national average and there are fewer wind farms. Together, these three regions account for 4% of U.S. wind capacity as of August 2022.