Long term trends in precipitation and temperature determine a region's climate. Dane County's climate is typical of the Great Lakes states. Winters tend to be long, cold and snowy, while summers are short and, at times, humid. The temperature ranges from an average of 18.5° F in January to 71.6° F in July. Average annual precipitation is about 35 inches, with 68 percent falling from April through September. June is the wettest month, with average precipitation of 4.8 inches, and January is the driest, with about 1.2 inches. Snowfall averages 51 inches per year. The ground usually begins to freeze at the end of November and thaws in mid-April. Maximum frost depth averages over 18 inches. Severe storms often occur from late fall through mid-spring. The potential for runoff and severe erosion is often highest in March and early April when heavy rainstorms and snowmelt occur on bare or sparsely covered ground.

By 2055, it is predicted that all seasons will warm by at least 5°F in Dane County (spring by 6°F, summer by 5°F, autumn by 6°F, and winter by 7°F). Winter is expected to show the most warming, which will result in fewer days with frozen conditions. Our future climate will be more like what is currently observed in central Illinois. Climate models also show that winter precipitation will increase about by 0.5 inches.

The Wisconsin Initiative on Climate Change Impacts (WICCI) documented how local climate is likely to change, impacts of those changes, and how the region can adopt strategies for adaptation. These are all important components of planning for climate change. Working groups for infrastructure, stormwater, and water resources are all addressing how anticipated changes should influence current management decisions.

The Dane County Council on Climate Change coordinates the community's work to adapt to the impacts of our changing climate. Initiatives center on reducing local green house gas emissions, promoting renewable energy, and preparing for future storm events. The County has allocated money for infrastructure updates so that the region is better prepared for large volume storms and future flooding. The Council is developing a Dane County Climate Action Plan which focuses on deep decarbonization and will coordinate efforts in reducing the local use of green house gases.

Temperature and precipitation directly impact our local water resources, and local water quality will inevitably be impacted by future climate change. Winter ice cover along with stream, groundwater, and lake levels are all influenced by climactic trends. Native biota are also adapted to the local climate, and as changing conditions alter habitat (such as water temperature), nonnative and nuisance species can prosper as native species struggle. From maintaining high quality aquatic habitat to successfully managing stormwater runoff, planning for climate change is an important part of managing regional water resources.