The Oklahoma Mesonet is a statewide meteorological observing network that provides real-time data from 115 stations with at least one station in every county. Data are recorded every 5 minutes and include meteorological variables such as air temperature, wind speed and direction, and rainfall. In 1996, Campbell Scientific 229-L (CSI 229-L) heat dissipation soil moisture sensors were installed at 60 Mesonet sites at depths of 5, 25, 60, and 75 cm to provide continuous observations of soil moisture. The soil moisture sites collect observations every 30 minutes and are quality assured through automated multi-pass procedures. The 229-L sensors measure a temperature difference, which is a change in the sensor temperature after a heat pulse is introduced. From the measured temperature difference, hydrological variables such as soil water content, soil matric potential, and Fractional Water Index (FWI) are calculated. In 1999, approximately 90 additional 229-L sensors were deployed at Mesonet sites across Oklahoma, bringing the total number of stations observing soil moisture data to 100.

In October 2002, quality assured soil moisture data was made available (real time) to the public. A suite of soil moisture products were added to the existing Mesonet data internet web pages. These products include maps of FWI and soil matric potential categories for each of the four depths of the network. The user can also chose a specific soil moisture index, depth and date to view archive data. In addition, time series plots of FWI and soil water content can be viewed at each site location. These plots are also customizable by the user by allowing specific time periods of data to be viewed. The utility of such products allows meteorologists, climatologists, decision makers, and the general public to continuously monitor soil moisture conditions across Oklahoma and to assess critical trends in soil water shortage or abundance. The added utility of real-time soil moisture monitoring combined with information obtained from collocated measurements of atmospheric variables provides a unique framework to monitor short and long-term climatic changes such as periods of sustained drought conditions.