Twentieth‐century climate change in New England and New York, USA

We have analyzed twentieth‐century temperature data from 73 climate stations in New England and New York. Linear regression gives a 100‐year temperature change (Δ T 100 ) for each station. All but two stations show an increase over this time, giving a regional area‐weighted average Δ T 100 of 1.11°C. Average Δ T 100 values for each state are all positive, ranging from 0.86°C to 1.86°C. Spatial autocorrelation analysis reveals a southeastern New England cluster of stations with relatively large Δ T 100 , and a cluster in western New York with low but still positive Δ T 100 . Thus, at differing spatial scales, temperature in this region increased during the twentieth century, in most cases by more than the global average increase of some 0.6°C during this same period. Our results contrast markedly with the New England Regional Assessment, and may have implications for other regional assessments undertaken under the auspices of the U.S. Global Change Research Program.