San Juan Fishing Forecast
The San Juan in New Mexico behaves like a classic tailwater: cold, predictable releases that stretch the trout season when freestone neighbors run warm or muddy. Anglers target rainbow trout and brown trout across riffles, seams, and undercut banks in this region, with prime dry-fly and nymph windows typically clustering in March through November. USGS gauge 08379500 tracks live flow and temperature for planning wade or float days. Local tactics angle: The San Juan River below Navajo Dam is one of the finest tailwaters in the United States, producing trophy rainbow trout in incredible numbers. Fish counts exceed 15,000 trout per mile. TroutFishing pairs hatch timing with solunar windows so you know when to be on the water—not just where.
Constant 70°F water flows through the San Juan at 0 CFS CFS — 5/10 today. Top pick: a Parachute Hopper.
Open year-round
Quality Waters below Navajo Dam. Year-round. Barbless hooks required in Quality Waters section. One trout over 20in
Forecast and on-page guide updated September 9, 2026 (UTC). Open the app for hourly conditions.
Today's Fishing Conditions
Fair
Updated 8:47 AM
70°F
--
5 AM - 7 AM
Parachute Hopper
Free forever • No signup required • Hourly updates
Quick Facts
Rainbow Trout and Brown Trout
tailwater
54°F - 64°F
What Makes the San Juan Unique?
Signature hatch or window
BWO (Mayfly) is a headline hatch to watch in September. Peak activity often tracks 38–55°F water temps.
Distinctive access
Texas Hole: Famous pool below Navajo Dam.
Rules anglers miss
Quality Waters has strict regulations.
September Fishing Tactics
Primary Targets
Recommended Tactics
Fall fishing improves. BWOs return, browns become aggressive.
September Hatches
BWO
Mayfly
Blue Wing Olives hatch on overcast days, spring and fall
Caddis
Caddis
Evening caddis hatches prolific through summer
Hopper
Terrestrial
Grasshoppers effective on windy afternoons
Trico
Mayfly
Early morning spinner falls, tiny flies
October Caddis
Caddis
Large fall caddis, evening emergence
Scud
Crustacean
Year-round tailwater food source
Year-Round Fishing Guide
| Month | Water Temp | Tactics |
|---|---|---|
| January | 32-38°F | Nymphing, Midges, Small Streamers |
| February | 32-40°F | Nymphing, Midges, Small Streamers |
| March | 36-46°F | Dry Flies, BWOs, Skwala |
| April | 42-52°F | Dry Flies, BWOs, Skwala |
| May | 48-58°F | Dry Flies, BWOs, Skwala |
| June | 54-64°F | Hoppers, Terrestrials, PMDs |
| July | 58-68°F | Hoppers, Terrestrials, PMDs |
| August | 60-70°F | Hoppers, Terrestrials, PMDs |
| September(Now) | 54-64°F | Streamers, BWOs, October Caddis |
| October | 46-56°F | Streamers, BWOs, October Caddis |
| November | 38-46°F | Streamers, BWOs, October Caddis |
| December | 32-40°F | Nymphing, Midges, Small Streamers |
Spawning Seasons
Please respect spawning fish and their redds. Avoid fishing over actively spawning trout.
Brown Trout
Spawn months: October, November
Night spawning common. Males become very dark with pronounced kype during spawn.
Rainbow Trout
Spawn months: March, April
Resident rainbow trout spawn in smaller tributaries and tend to build smaller redds than steelhead.
Access Points & Parking for San Juan
Texas Hole
Famous pool below Navajo Dam.
Kiddie Hole
Quality fishing access.
Upper Flats
Technical fishing in flats.
Baetis Bend
Famous for BWO hatches.
How to Fish San Juan: Tips & Tactics
The San Juan River below Navajo Dam is one of the finest tailwaters in the United States, producing trophy rainbow trout in incredible numbers. Fish counts exceed 15,000 trout per mile.
Best Times of Day
Year-round fishing is excellent. Midge and BWO hatches occur daily. Morning hours offer the best surface activity.
Recommended Techniques
Match the prolific midge and mayfly hatches. Sight fishing to specific trout is highly productive. Fine tippets and small flies essential.
Water Conditions
Cold dam releases create exceptional conditions. Water clarity is excellent. Fish are numerous but can be selective.
Fly Selection
Midge patterns in sizes 20-26 essential. BWO patterns for mayflies. San Juan Worms work year-round.
When is the Best Time to Fish San Juan?
Spring
Excellent fishing continues. BWO hatches increase.
Summer
Year-round tailwater stays cool. Fish early morning.
Fall
Outstanding conditions. Less crowded.
Winter
Cold water fishery produces. Midge focus.
Recommended Equipment for San Juan
Rod
9-foot, 4 or 5-weight for technical fishing.
Line
Floating line with long leaders.
Leader & Tippet
12-15 foot leaders, 6X-7X tippet.
Waders
Breathable waders. Cold water year-round.
Essential Flies
San Juan Fishing Regulations
Season
Open year-round.
Limits
One fish over 20 inches in Quality Waters.
Special Regulations
Quality Waters has strict regulations.
Bait Restrictions
Single barbless flies only in Quality Waters.
Notes
New Mexico Game and Fish manages this trophy water.
Always verify current regulations with New Mexico fish and wildlife agency before fishing. Regulations can change annually.
Fly Shops & Guides Near San Juan
Local Fly Shops
- Abe's Motel & Fly Shop - Navajo Dam
- Rizuto's Fly Shop
- San Juan River Lodge
Guide Services
- San Juan River Lodge Guides
- Abe's Guide Service
- Rizuto's Guides
Optimal Fishing Conditions
Optimal Flow
500 - 2500 CFS
Best fishing conditions
Optimal Water Temperature
42° - 55°F
Ideal for active trout
Other Rivers You Might Like
Popular forecasts outside New Mexico—great for trip planning and comparing conditions.
San Juan — frequently asked questions
When is the best time to fish the San Juan?
Fall fishing improves. BWOs return, browns become aggressive.
What flies should I bring to the San Juan?
For the San Juan (tailwater), carry: Midge, RS2, San Juan Worm, BWO, Annelid.
What water temperature is best for trout on the San Juan?
On the San Juan, trout hold between 42° and 55°F. Because the river is dam-fed, the temperature stays in this band year-round.
Do I need a fishing license for the San Juan?
Yes — you need a valid New Mexico fishing license to fish the San Juan. Local season: Open year-round.. Daily limit: One fish over 20 inches in Quality Waters..
What hatches should I watch for on the San Juan in September?
BWO is the signature hatch on the San Juan in September. Match size and adjust leader size to 5X-6X. The fish key in on the emergence during low-light hours, so plan to be on the water at first light.
Ready to Fish the San Juan?
Get real-time forecasts with AI-powered fly recommendations, live water conditions, and hatch predictions.
Get Your Forecast