Seasonal temperature distribution at Snake River Mile 192, 1991-1997. The difference in temperatures upriver compared to downriver also exhibits a seasonal pattern. Generally, the water is cooler downstream in the fall and winter and warmer in the early spring and late summer. During the summer juvenile fall chinook migration from Hells Canyon, the water may be either warmer or cooler downstream. Figure 5 .
Positive values indicate warming.
Figure 6 . Temperature difference between RM 246 and RM 192, 1991-1997. Positive values indicate warming. Although there are seasonal patterns of flow and water temperature at Hells Canyon Dam, the two properties are uncorrelated as illustrated in Figure 7. Figure 7 .