University of Arizona
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Archived Accumulated Growing Degree Average and Anomaly Products (1981-2010 climate normal)

posted on 2022-02-11, 16:27 authored by USA National Phenology Network
Heat accumulation is commonly used as a way of predicting the timing of phenological transitions in plants and animals. The USA National Phenology Network (USA-NPN) hosts a suite of accumulated growing degree day products to serve a number of audiences. In 2022, the USA NPN updated all long-term average and anomaly products in this suite to use the more recent climate normal period (1991-2020).

This record contains the archived layers that use the prior normal (1981-2010). The data consists of geotiff rasters with daily accumulated growing degree day values. The "average" files show the daily GDD value averaged across 1981-2010. The "anomaly" files show for each day 2016-2021, the difference between that day's accumulation and the long term average. These products begin accumulation on January 1 and use either a 32F or 50F base temperature.

The products using updated normals can be accessed here: Accumulated Growing Degree Days, Continental United States, 1981 - Current Year

For inquiries regarding the contents of this dataset, please contact the Corresponding Author listed in the README.txt file. Administrative inquiries (e.g., removal requests, trouble downloading, etc.) can be directed to