Coming off 90 and 100 degree temperatures across the state this week, a look ahead in the long term forecast shows cooler temperatures returning again to South Dakota and the corn belt. It seems as if we have written this same story several times already this growing season. Overall, growing degree days (GDD) in the corn/soybean regions have been near average or just slightly below average, despite the apparent cooler than average weather.
Corn is still five percent ahead of the five year average for tasseling. Soybeans are 4 percent ahead on setting pods. Calls have already started to come in with concerns about fall frost and inability to reach black layer/maturity this season. I have tried my best to reassure folks that we are not in any danger at this point, despite the late planting, and also that it is too early to predict when the first hard freeze will occur.
If there is anything to be concerned about at this point in the season, it might be the recent dryness across the row crop region of the state. Vermilion is currently running the race to be the second coolest July on record. But if we go much longer without significant moisture as we move into grain fill for corn and soybeans, we could see some yield impact. The silver lining might be that cooler temperatures will reduce the water demand by the crop, but moisture is needed nonetheless in the near future.
The current 6-10 day and 8-14 day forecasts from NOAA’s Climate Prediction Center are consistent in projecting cooler than average temperatures across the eastern states, including our area, and also drier than average over the Dakotas.
The U.S. Drought Monitor this week showed D0 (Abnormally Dry) across some parts of South Dakota. I would expect that area to grow as our dry climate pattern is forecast to continue in the next 1 to 2 weeks.
Source : SDSU