Data from: Comparing winter versus summer deepwater dissolved oxygen depletion with the potential for cross-seasonal forecasting of deepwater oxygen availability

Depletion of deepwater dissolved oxygen (DO) in lakes has become increasingly prevalent and severe due to many external stressors, potentially threatening human-derived ecosystem services ranging from drinking water quality to fisheries. Using year-round, high-frequency DO data from 12 dimictic lakes, we compared three measures of deepwater DO depletion during winter and summer:  DO depletion rate, DO minimum, and hypoxia duration. Hypoxia (DO < 3 mg L^-1) occurred in over half of the lakes and persisted an average of 83% longer in summer than in winter. While we found no difference in DO depletion rates between winter versus summer, these rates were strongly related to lake morphology in winter but water transparency and temperature in summer. Winter hypoxia duration was negatively related to summer hypoxia duration, suggesting potential utility for forecasting DO depletion in the subsequent summer. Spring mixing efficacy was strongly related to winter minimum DO saturation and hypoxia duration, and was also a strong predictor of summer minimum DO saturation and hypoxia duration. Hence, these cross-seasonal patterns suggest deepwater DO metrics can be used to forecast DO availability in subsequent seasons, modified by the relative importance of morphology, water transparency, and temperature. These findings can allow for improved, early management when DO is predicted to be critically low based on previous seasons’ DO measurements, which can work to minimize the negative consequences for water quality and fisheries health associated with severe DO depletion.