Long-Term Temperature Trends of the Hudson River: A Study of the Historical Data

Abstract

Water temperature data from the Hudson River at Poughkeepsie from 1908 to the present were acquired. This long-term data set contains (with a few gaps) daily water temperatures at a constant location for the 82-yr period. We hypothesized that water temperatures, because of the dampened variability as compared to air temperatures, would provide a useful record of long-term temperature change. The data were analyzed for statistically significant trends, both annually and monthly for long-term and 10-yr blocks; both warming and cooling trends within all categories were found. The longest significant trend was a 0.12°C per decade increase from about 1920 to 1990. This increase, which was statistically significant for both simple regression and time-series analysis, is within the limits of the suggested rates of change on the global scale. On the other hand, there was no significant trend from the beginning of the record (1908) to the present, due to an apparent dramatic cooling from 1908 to about 1920.