Systematic weather observations began in Alaska more than 150 years ago and by the beginning of the 20th century there were nearly 50 stations around the state, located primarily at settlements in coastal areas. The mid 20th century brought a significant increase in the number of stations and with it, a more detailed picture of Alaska's varied climate could be achieved. The primary factors controlling the climate are: latitude, proximity to water, topography, and semi-permanent pressure features. These factors result in three primary climate regions found in the state: arctic, maritime, and continental. However, local terrain features and the presence of sea ice can have a dominant role in determining the microclimate of a given location. As is the case for most high latitude regions, climate variability on a temporal scale is quite high, especially for the extreme continental climate of the Interior region. This variability is significantly greater for the cold seasons, than for summer. One type of longer-term variability in the temperature record is correlated to a large-scale pattern of multi-decadal variability in the Pacific basin - the Pacific Decadal Oscillation (PDO). The mean annual temperature in Alaska has increased on the order of 1.9°C since 1950, however the change has not been linear and shows a step-wise change in the mid 1970s associated with a regime shift in the PDO. The magnitude of temperature change is greater for the cold seasons and for the continental and arctic climate regions than for the warm season and maritime regions. This presentation will discuss the primary features of Alaska climatology as well as variability and observed change in the historical record.