According to the Köppen Classification, Juneau has a humid continental climate despite its coastal location, though it is influenced by the Pacific Ocean. Average annual rainfall ranges from 55 inches (1,400 mm) to over 90 inches (2,300 mm) depending on location; annual average snowfall at Juneau International Airport is 93 inches (236.2 cm). The average high temperature in July is 65 °F (18 °C), and the average low temperature in January is 20 °F (-7 °C).

Juneau is only accessible via sea or air. Cars and trucks are transported to and from Juneau by barge or ferry.The only airport in Juneau is Juneau International Airport. Alaska Airlines is as of 2008 the sole commercial jet passenger operator. MarkAir and Western Airlines and its successor, Delta previously served Juneau. The fishing industry used to be a major part of the Juneau economy. Until recently, Juneau was the 49th most lucrative U.S. fisheries port by volume and 45th by value taking in 15 million pounds of fish and shellfish valued at 21.5 million dollars in 2004 according to the National Marine Fisheries Service.