Cold Temperatures & The Growing Degree Day Calculator


The primary discussions I’ve had during the past couple of weeks are cold temperatures. Are we colder than average? Yes, the weather remains a large driving factor in farming, and there is a calculator designed to help answer this question on the Small Grains web site. The Growing Degree Day (GDD) Calculator, is based on the AgWeatherNet weather stations across the region. A GDD is a measure of heat units that accumulate over time and is calculated by taking the average daily temperature (high temp + low temp divided by 2) and subtracting 32. For example, a high temp of 52°F and a low of 40°F has 14 GDD. [ (52+40)/2 – 32 = 14].

At the Davenport location, currently, there are a total of 673 GDD, and the average GDD over the last 10 years has been 654. This is very close to the 10-yr average. The most GDD was 1002 in 2016, and the lowest GDD was 405 GDD in 2009.

Growing degree day calculator for 2009 - 2020.

For questions or comments, contact Aaron Esser via email at or via phone at 509-659-3210.