Midge and Yellow Sally window opening on NM's Rio Grande and San Juan

What's biting

What's next

Without current flow or temperature readings, forward projections lean on seasonal norms rather than hard numbers — treat the timing windows below as starting points to verify against local conditions before you load the truck.

On the San Juan tailwater below Navajo Dam, summer follows a reliable pattern. Cold releases from the dam's lower intake suppress water temperatures relative to the air, keeping trout active even as July approaches. The full moon this week can shift feeding to low-light windows — expect the best dry-fly and surface midge action in the first 60–90 minutes of daylight and the final hour before dark. MidCurrent's recent tying coverage points to midge patterns built for 'clear, pressured water of tailraces,' and sizes 20–24 in red, black, and olive are where to start on the San Juan. When surface activity fades mid-morning, drop to scud and Baetis nymph imitations — fish them slowly through the deeper, slower channels where tailwater trout hold during peak heat.

On the Rio Grande, the outlook depends on how quickly runoff has cleared — a variable we can't pin down without gauge data this cycle. In most years, the canyon above Taos is fishable and clearing by the final week of June. If clarity has arrived, look for trout holding where current breaks against boulders and undercut banks. Caddis Fly (OR) notes that Yellow Sallies are 'often overlooked' relative to larger stoneflies — watch for them in slower, rocky runs through late morning. A size 14–16 Yellow Sally dry or a jigged nymph fished as a dropper is the starting move; if the hatch isn't showing yet, a hopper-dropper rig becomes a strong summer alternative as July approaches.

For the Fourth of July weekend: mornings before 9 a.m. and evenings after 6 p.m. are the windows worth planning around. Midday heat suppresses surface activity on both rivers; go heavy on the nymph rig and work slower, deeper slots during the midday hours. With the full moon overhead this week, the last light of evening on the San Juan in particular can produce exceptional midge and dry-fly action — an edge worth staying for.

Context

Late June on New Mexico's two signature freshwater rivers follows a fairly predictable arc, though year-to-year variation in snowpack can shift the calendar by several weeks in either direction.

The Rio Grande above Taos draws most of its flow from southern Colorado snowmelt. In an average year, peak runoff lands in late May to early June, with the river dropping and clearing through the back half of June. By the final week of the month — right where we are now — conditions are often in the seasonal sweet spot: flows manageable for wading, clarity adequate for sight-fishing, terrestrial and hatch activity building. Heavy snowpack years push that window out to mid-July, keeping the river off-color through the holiday weekend. Without gauge data this cycle, it isn't possible to confirm which scenario is playing out in 2026.

The San Juan below Navajo Dam is a different animal. As a regulated tailwater, it fishes through summer in ways free-flowing mountain rivers cannot. Gink and Gasoline notes that trico spinner falls on Western tailwaters 'build as summer progresses' — their South Platte reference translates reasonably to the San Juan, where comparable trico populations typically arrive in earnest by mid-July. Late June is the lead-in phase: midges and Baetis dominate, and pressured fish on this Gold Medal water reward precise, drag-free presentations over brute-force tactics.

No comparative data from this fetch cycle confirms whether 2026 is running early, late, or on schedule across NM. This update draws on historical norms only. Check USGS WaterWatch and NM Game & Fish current advisories before making the drive to either river.