This data set contains information on a spatial survey of dissolved organic matter (DOM) across lakes and wetlands in the Northeast and Midwest, USA and modeled long-term changes in light limitation and whole-lake productivity in a suite of lakes in the Adirondack State Park, New York, USA. Widespread long-term increases in DOM have been observed in many lakes in a process known as browning. This data set enables the assessment of potential changes in dissolved absorbance and dissolved organic nutrients associated with browning. This data set accompanies a manuscript in review at Limnology and Oceanography: Letters.