If you are looking for actual NWS COOP observations with no estimating and very little quality control done, check out this page.
This page allows you to download observed, sometimes quality controlled, and sometimes estimated once daily reports from various NWS networks including COOP. More detailed documentation exists here and should be consulted before using the data. Backend documentation exists for those wishing to script against the backend service.
Data is also available from the following states:
Publications Citing IEM Data (View All)
These are the most recent 10 publications that have cited the usage of data from this page. This list is not exhaustive, so please let us know if you have a publication that should be added.
- McDaniel, M., C. Dutter, et al. 2026, A minimally destructive method for 2-dimensional soil and root mapping in row crops. Plant and Soil. https://doi.org/10.1007/s11104-026-08632-2
- Zhen, X. and W. Sadok. 2026, Increasing transpiration sensitivity to rising vapor pressure deficit raises U.S. spring wheat yields under current and future climates: a two-model simulation study. in silico Plants, diag013 https://doi.org/10.1093/insilicoplants/diag013
- St Cyr, M. 2026, Perennial ground covers: A mitigation strategy to nitrous oxide (N₂O) emissions for maize cropping systems. Masters Thesis. Iowa State University https://www.regenpgc.org/wp-content/uploads/2026/05/2026-05-19-StCyr-OFFICIAL-THESIS.pdf
- Kimtai, D., C. Schmidt, et al. 2026, Pathogenicity and fungicide sensitivity of Phaeocytostroma ambiguum, a fungal species recovered from the crowns of corn plants. APS Online. https://doi.org/10.1094/PDIS-02-26-0383-RE
- Saha, G., F. Rahmani, et al. 2026, Analyzing the deep learning approach-based modeling framework to understand the critical environmental factors of predicting daily nitrate concentrations. Journal of Environmental Management. Vol 404 https://doi.org/10.1016/j.jenvman.2026.129539
- Thilakarathne, A., M. Woods, et al. 2026, Diversified cropping systems enhance soybean resilience to extreme drought. Agriculture, Ecosystems & Environment. Volume 399 https://doi.org/10.1016/j.agee.2025.110180
- Huang, H., P. Cao, et al. 2026, Combining in-field and edge-of-field practices enhances nitrate reduction in tile-drained catchments. Water Research https://doi.org/10.1016/j.watres.2026.125852
- Aina, O. and J. Brotzge. 2026, A Comparison of COOP, ASOS, and Kentucky Mesonet Precipitation. J of Atmospheric and Oceanic Technology. https://doi.org/10.1175/JTECH-D-25-0063.1
- Seraglio, N., A. Singh, et al. 2026, Optimizing planting date for mung bean cultivars. Crop, Forage and Turfgrass Mgnt. https://doi.org/10.1002/cft2.70113
- Kwakye, S., A. Garg, et al. 2026, Effect of soil health management on soil water storage for climate resilience. Agrosytems, Geosciences, and Environment. Vol 9 https://doi.org/10.1002/agg2.70322