Fishability Summary (0–100)
PRIME 75–100 Get on the water
GOOD 60–74 Worth the trip
FAIR 45–59 Workable — pick your window
MARGINAL 30–44 Tough bite likely
TOUGH < 30 Maybe tie flies instead
Wind Speed (6 wt rod)
0–8 mph Negligible impact · easy casting
8–12 mph Minor impact · still comfortable
12–18 mph Moderate · shorten casts, heavier flies
18–22 mph Significant · accuracy & distance suffer
22+ mph Adverse / unsafe · stand down
Pressure Trend (3-hr Δ, inHg)
RAPID FALL ≤ −0.10 · feeding now, fish before the storm
FALLING −0.10 to −0.03 · pre-front feeding frenzy 🎯
STABLE −0.03 to +0.03 · reliable baseline activity
RISING +0.03 to +0.10 · steady feeding, good bite
RAPID RISE ≥ +0.10 · post-front spike, bite often stalls
Water Temperature (trout)
< 45°F Sluggish · slow presentations
50–65°F Ideal feeding window
65–68°F Marginal · fish early/late
> 68°F Stressful · consider standing down
Flow brackets — per stream
Driftless tributaries range from tiny spring creeks to the lower Root · thresholds calibrated per gauge (score Δ in parens)
Very low Spooky fish, tiny tippet (−10)
Low-normal Good wade visibility (0)
Prime Ideal wading & drifts (+5)
Elevated Streamers & edges (−5)
High / blown Off-color, unsafe wading (−20)
Driftless Note
These are spring-fed limestone streams — water temp and flow stay
more stable than freestone rivers. Short-term rain spikes, air
temp, and especially barometric trend are the strongest
daily signals for SE Minnesota fly fishing.