wildlife species including woodland caribou, Canada lynx, grizzly bear, and wolves. The large lakes in the Idaho panhandle attract birds on the Pacific Flyway, and bird watching is popular on Lake Coeur d'Alene, especially from November to February when bald eagles come annually to feed on the spawning kokanee. The Cougar Bay Nature Preserve on the northeast portion of Lake Coeur d'Alene is the closest and most accessible nature preserve for wildlife viewing, as it is located a few minutes from downtown Coeur d'Alene. Environmental concerns have come as a result of upstream hardrock mining and smelting operations in the Silver Valley. The Coeur d'Alene Basin, including Lake Coeur d'Alene, is polluted with heavy metals such as lead and was designated a superfund site in 1983 that spans and of the Coeur d'Alene River. The majority of the lake bed is covered in a layer of contaminated sediment and local health officials at the Panhandle Health District advise the lake's visitors to wash anything that has come into contact with potentially lead-laced soil or dust in the Coeur d'Alene River basin. Climate Coeur d'Alene has, depending on the definition, a dry-summer continental climate (Köppen Dsb) or a warm-summer Mediterranean climate (Csb), characterized by a cold, moist climate in winter, and very warm, dry conditions in summer. The daily mean temperature ranges from in December to in July and August. Temperatures exceed on 13 days per year, only occasionally reaching , and there may be several nights below . The average first and last freezes of the season are October 12 and May 3, respectively. The city straddles the border between USDA Plant Hardiness Zones 6B and 7A. The Spokane–Coeur d'Alene area has many microclimates that can have different weather patterns and observations from the nearby official reporting stations used by the National Weather Service due to the diversity of the topography and other factors. For instance, northern Idaho experiences more precipitation in rain and snow than eastern Washington from weather systems originating from the Pacific Ocean because it is on the windward side of the Rocky Mountains. Average annual rainfall is and the average annual snowfall is . Northern Idaho weather is influenced by both maritime and continental weather systems. Moist air masses from the coast are released as precipitation over the North Central Rockies forests, creating the North American inland temperate rainforest, and dry air masses from Canada and