The Iowa Environmental Mesonet (IEM) collects environmental data from cooperating members with observing networks. The data are stored and made available on this website.
Boone County Corn Yields
Posted: 23 May 2025 05:30 AM, Views: 507
Tags: corn
With USDA NASS's recent release of 2024 county corn yield estimates, it is a good time to plot up a bit of a deep dive comparing yearly yields and weather metrics. The featured chart combines the Boone County NASS corn yields with the long term Ames climate site data. As as aside, while Ames is mostly in Story County, the long term climate site was at the research farm west of town in Boone County for a good chunk of the period of record data. The top left panel shows the yearly yield values along with a linear trend line, trailing 10 year average, and simple mean plotted. The lower left panel plots the yearly departure against the 10 year trend line. The three worst and three best years against the trend are assigned special markers for the right side eight panels presenting various weather metrics between 1 May and 30 September. The bottom two right side panels tell a good story with too little and too much precipitation being negative for corn yields along with increasing Stress Degree Days (SDD)s decreasing yields. Of course, there is no magic metric between weather variables and corn yields, but it is certainly fun to play around with the data and see if you can spot any trends. You can follow the "generate this chart" link and generate more charts like this for your periods and location of choice.
Rate Feature
Previous Years' Features
2024: Polk-Story Tornado
2023: Soybean Progress
2022: Chilly Sunday Morning
2019: Potential ET
2018: Besting May 1934
2017: 23 Years of RADAR Data
2014: Quick Three Inches
2013: GDDs
2012: Getting the corn planted
2011: Widespread severe event
2008: Convective Complexes
2007: Not much rain yet
2005: An outstanding Sunday!
2004: Extreme Rainfall
2003: A bit below normal
2002: Rainy Thursday
ISU Memorial Union, IA Webcam:
Most Popular (List Apps)
New IEM LSR App
Posted: 22 May 11:15 AM
CoCoRaHS Update
Posted: 29 Jan 10:29 AM
13-16 Jan Network Issue [resolved]
Posted: 15 Jan 10:13 AM
Alaska Marine Warnings
Posted: 8 Jan 9:28 AM
Wagering on ASOS Temperatures
Posted: 4 Dec 10:39 AM
Sign up for the Daily Bulletin
Current Website Performance:
Bandwidth: 46.1 MB/s
Total Website: 2,665 req/s
API/Data Services: 118.5 req/s
API Success: 100%
Soil Temperatures

Data from the Iowa State Soil Moisture Network is found on this website and daily soil temperature averages are used to produce the highlighted analysis.