NW Iowa had sites get down to 30 degrees on Sunday morning. Today the phone calls, for limited parts of NW Iowa, have been coming in. So, I thought that I would send this to help your decision making - if you have questions. Hopefully, it is a limited part of the area. But if it is you, I think we have some information that might help.
Last year there was an article on the ISU ICM Blog site titled "Assess frost injury, crop recovery" written after a May 29, 2021 frost that caused some significant damage in parts of northern Iowa. Follow the link above to review the article written by Paul Kassel. Damage occurred a little later in the growth stage, but the information is still very good. A couple of key notes - for corn, the growing point is well below the surface. Recovery is likely, but too soon to tell for certain today. Soybeans - ideally wait a few days to see if recovery starts. Soybean plants with green cotyledons/seed leaves may recover, because there are two growing points at the axils of the cotyledons. See the pictures included in this article.
More on Frost and Corn - In 2020 I wrote an ISU ICM Blog article titled "Recovery of frosted corn – a case study." If you have corn concerns check it out. Here are some pictures of a field I followed after a 2013 frost that might help you understand the potential timeline for recovery.
I hope this helps. Better yet - I hope you don't need this information!
Extension Field Agronomist
Published in Iowa State University Extension and Outreach