Firehole River Fishing Forecast
The Firehole River is a Wyoming freestone where flows and clarity swing with storms—meaning the bite window can flip in a single afternoon. Anglers target brown trout, rainbow trout, and brook trout across riffles, seams, and undercut banks in this region, with prime dry-fly and nymph windows typically clustering in late June through September. USGS gauge 06036905 tracks live flow and temperature for planning wade or float days. Local tactics angle: The Firehole River flows through Yellowstone's geyser basins, offering unique fishing for brown and rainbow trout amid thermal features. TroutFishing pairs hatch timing with solunar windows so you know when to be on the water—not just where.
Constant 74°F water flows through the Firehole River at 192 CFS CFS — 5/10 today. Top pick: a Cicada.
Open Sat of Mem Day wknd — First Sun in Nov
YNP fishing permit required. Thermally influenced - runs too warm Jun-Sep in many sections
Forecast and on-page guide updated September 9, 2026 (UTC). Open the app for hourly conditions.
Today's Fishing Conditions
Fair
Updated 9:51 AM
74°F
192 CFS
5 AM - 7 AM
Cicada
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Quick Facts
Brown Trout, Rainbow Trout, and Brook Trout
freestone
48°F - 58°F
What Makes the Firehole River Unique?
Signature hatch or window
BWO (Mayfly) is a headline hatch to watch in September. Peak activity often tracks 45–58°F water temps.
Distinctive access
Biscuit Basin: Upper river access near geysers.
Rules anglers miss
Park fishing permit required.
September Fishing Tactics
Primary Targets
Recommended Tactics
Excellent fall fishing. Browns aggressive.
September Hatches
BWO
Mayfly
Spring and fall BWO fishing. Geothermal influence extends season.
Speckled Dun
Mayfly
Slower water sections. Comparaduns effective.
Year-Round Fishing Guide
| Month | Water Temp | Tactics |
|---|---|---|
| January | 32-38°F | Deep nymphing, Midges, Streamers |
| February | 33-40°F | Midges, Small nymphs, Deep pools |
| March | 36-45°F | BWO dries, Streamers, Early stonefly nymphs |
| April | 40-50°F | Skwala dries, BWO patterns, Streamers |
| May | 45-55°F | Mother's Day Caddis, Nymphing, Streamers |
| June | 50-60°F | Salmonfly dries, Golden Stones, PMDs |
| July | 55-68°F | PMDs, Hoppers, Caddis, Attractor dries |
| August | 55-70°F | Hoppers, Tricos, PMDs, Terrestrials |
| September(Now) | 48-58°F | BWOs, Streamers, Hoppers |
| October | 40-50°F | Streamers, BWOs, Egg patterns |
| November | 35-42°F | Streamers, Deep nymphs, Egg patterns |
| December | 32-38°F | Deep nymphs, Midges, Slow presentations |
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.
Brook Trout
Spawn months: September, October
Males develop vibrant red bellies and white-edged fins during spawning. Early fall spawners.
Access Points & Parking for Firehole River
Biscuit Basin
Upper river access near geysers.
Midway Geyser Basin
Access near Grand Prismatic.
Firehole Canyon
Canyon access below falls.
Madison Junction
Confluence with Madison.
How to Fish Firehole River: Tips & Tactics
The Firehole River flows through Yellowstone's geyser basins, offering unique fishing for brown and rainbow trout amid thermal features.
Best Times of Day
Fall is the best season after summer thermal heating. Spring fishing before thermal warming is excellent. Summer waters can be too warm.
Recommended Techniques
Match the prolific hatches. The Firehole has unique insect life due to thermal influence. Stealth is essential.
Water Conditions
Thermal inputs warm the water in summer. Fall cooling brings the best fishing. Unique fishing among geysers.
Fly Selection
BWO patterns work well. Caddis hatches are prolific. PMD and sulfur patterns. The Firehole has unique hatches.
When is the Best Time to Fish Firehole River?
Spring
Excellent fishing before thermal warming.
Summer
Water can be too warm. Fish early morning only.
Fall
Prime season as water cools. Best fishing.
Winter
Closed - Yellowstone winter access limited.
Recommended Equipment for Firehole River
Rod
9-foot, 4 or 5-weight.
Line
Floating line for dry flies.
Leader & Tippet
9-12 foot leaders, 5X-6X tippet.
Waders
Breathable waders. Watch for thermal features.
Essential Flies
Firehole River Fishing Regulations
Season
Check Yellowstone National Park regulations.
Limits
Catch-and-release for wild trout.
Special Regulations
Park fishing permit required.
Bait Restrictions
Artificial flies and lures only.
Notes
Yellowstone National Park regulations apply.
Always verify current regulations with Wyoming fish and wildlife agency before fishing. Regulations can change annually.
Fly Shops & Guides Near Firehole River
Local Fly Shops
- Blue Ribbon Flies - West Yellowstone
- Madison River Outfitters
- Parks' Fly Shop
Guide Services
- Yellowstone Guides
- Blue Ribbon Guides
- West Yellowstone Anglers
Optimal Fishing Conditions
Optimal Flow
200 - 500 CFS
Best fishing conditions
Optimal Water Temperature
50° - 65°F
Ideal for active trout
Other Rivers You Might Like
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Other Wyoming Trout Rivers
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Green
Snake River
North Platte River
Gibbon River
Firehole River — frequently asked questions
When is the best time to fish the Firehole River?
Excellent fall fishing. Browns aggressive.
What flies should I bring to the Firehole River?
For the Firehole River (freestone), carry: BWO, Caddis, PMD, Sulfur, Pheasant Tail.
What water temperature is best for trout on the Firehole River?
On the Firehole River, trout hold between 50° and 65°F. In summer, expect temps to swing with air temperature — fish early.
Do I need a fishing license for the Firehole River?
Yes — you need a valid Wyoming fishing license to fish the Firehole River. Local season: Check Yellowstone National Park regulations.. Daily limit: Catch-and-release for wild trout..
What hatches should I watch for on the Firehole River in September?
BWO is the signature hatch on the Firehole River 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.
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