The Cooperative Institute for Mesoscale Meteorological Studies is a research organization created in 1978 by a cooperative agreement between the University of Oklahoma (OU) and the National Oceanic and Atmospheric Administration (NOAA). CIMMS promotes collaborative research between NOAA and OU scientists on problems of mutual interest to improve basic understanding of mesoscale meteorological phenomena, weather radar, and regional climate to help produce better forecasts and warnings that save lives and property. CIMMS research contributes to the NOAA mission through improvement of the observation, analysis, understanding, and prediction of weather elements and systems and climate anomalies ranging in size from cloud nuclei to multi-state areas.

It is one of 16 NOAA Cooperative Institutes (CIs). On Oct. 1, 2021, CIMMS transitioned to become the new NOAA Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO), hosted at the University of Oklahoma.

CIMMS concentrates its research and outreach efforts and resources on the following principal themes: