Boulder Creek Fly Fishing Report – 12/5/25

Boulder Creek is low, clear, and cold this week with short but rewarding midday midge activity in town and higher in the canyon.

Updated: 12/5/2025

Flows are holding around 13 cfs which is expected for early winter. Water is clear, air temps are mild for December, and the trout are holding deep in slower pocket water. Week over week, flows are steady, clarity is unchanged, and the bite remains strongest in the warmest part of the day. Expect technical fishing, small flies, and highly targeted presentations. Maybe not your top choice right now. 

Listen to the Audio Overview

Conditions Summary

Flow (CFS): 13 cfs, steady; trout pushed into deeper mid-winter holding pockets.
Water Temperature: Low to mid 30s; stable and cold, with slight midday bumps.
Air Temperature: Upper 40s to low 50s; improves the midday window.
Clarity: Clear; stealth and long leaders required.
Crowds: Low during the week, moderate near Eben G. Fine on weekends.
Best Window: 11 am to 3 pm, when sunlight opens trout feeding.
Fishing Type Focus: Nymphing, because trout are hugging the bottom and feeding on tiny winter midges.

Weather

Expect cold mornings, frozen edges early, and modest warming through midday. The canyon stays shaded and colder; the town section often fishes better in early winter.

Top Flies in Your Box This Week

1. Zebra Midge Black 20–22

2. Top Secret Midge 20–24
3. RS2 Gray 20–22
4. WD40 Brown 20–22
5. Juju Midge Red 20–22
6. Spanish Bullet 18–20
7. Rainbow Warrior 20
8. Perdigon Olive 18–20
9. Micro Leech Black 12–14
10. Pheasant Tail 18–20

Pro Rig of the Week – Boulder Creek Winter Double-Midge

Top Fly: Spanish Bullet #18
Dropper: Top Secret Midge #22, 14 inches below
Indicator: Small yarn or micro indicator for soft landings
Weight: One tiny split shot, only enough to tick bottom occasionally
Target Water: Deep pockets, shaded canyon bowls, and slower winter troughs just upstream of town

Hatch Chart for December

Access Points

Eben G. Fine Park
Town water with slow runs and deeper pockets; good winter visibility.
Rating: ⭐⭐⭐⭐

Boulder Canyon Pullouts (Hwy 119)
Cold but excellent structure; deep canyon pockets hold wintering fish.
Rating: ⭐⭐⭐⭐

Fourmile Canyon Confluence
Reliable winter depth and softer seams in the mixing zone.
Rating: ⭐⭐⭐⭐

Settlers Park Area
Easy access, slower water, and dependable winter holding slots.
Rating: ⭐⭐⭐

East of 28th Street
Open, lower gradient with good nymphing lanes at low flows.
Rating: ⭐⭐⭐

Stop Here After the River

Avery Brewing Co. – Gunbarrel

Not the busiest brewery in Boulder, but one of the most consistently excellent. Spacious taproom, warm seating, and perfect after-fish energy.
What to order: White Rascal or the Ellie’s Brown Ale. Pair it with the green chile queso fries for the full winter-warmup treatment.

Local Regulations & Notes

• Boulder Creek Path areas can get busy; fish early or in shaded pockets
• Watch for thin ice shelves along canyon edges
• Barbless recommended for safer cold-water release
• Respect seasonal closures near spawning gravel if posted

FAQ

Q: Can you fish dries right now on Boulder Creek?
A: Rare, unless midges cluster in the town stretch on warm, windless days.

Q: Is the canyon or town fishing better?
A: Town generally fishes warmer; canyon fishes deeper but colder.

Q: Do I need 6X?
A: Yes. The creek is clear and technical at 13 cfs.

Q: Are small streamers worth trying?
A: Only micro leeches fished very slowly in deeper pockets.

Q: Best time of day?
A: Midday when temps bump up and trout activate.

Q: Can flows change quickly?
A: Not usually this time of year; winter is stable unless snowmelt spikes during warm spells.

Companion Article

Colorado Winter Trout Feeding Behavior in Clear, Low-Flow Rivers