Water released from Navajo Dam is a constant 42 F. Chest high neoprene or Gore-Tex waders are best year round. The best days to fish midges and Baetis on the surface are the windless and overcast ones. Add a little drizzle and things could be perfect. For the PMD's, a nice bright sunshiny day with a tiny breeze is the best. With constant 42F water temps the fish continue to feed all year, at an elevation of just under 6000 feet, the climate tends to be less severe than many trout waters.
Most springs see increased flows and somewhat off color water conditions.
Even at peak flows of 5000 cfs the river can fish well. With high water conditions floating is always a good option, but wade fishing is still possible in some areas. Summer and fall tend to be very consistent, with good insect activity and moderate to low flows. There is no closed season to the fishing on the San Juan. Below the Quality Water standard NM state regulations apply.