Conditions · Fox River
St. Charles Pool Fishing Outlook
Separate safety, trip-condition, season, productivity, direction, and evidence-quality decisions behind the current St. Charles Pool fishing outlook.
Updated Sep 10, 2026 12:55 AM CDT
Safety:
No Go
Trip Conditions:
Good
Season:
Open
Productivity:
Mixed
Direction:
Stable
Confidence:
High
A current safety restriction makes this a no-go.
The current NWS hourly forecast period is non-daylight, so the short-horizon operational result is NO GO. No material operational river limitation is currently identified.
Best Weather Window
Thu 6:00 AM – 6:00 PM
This is the longest continuous daylight period in the next 24 hours without a material operational weather limitation.
The current NWS hourly forecast period is non-daylight, so the short-horizon operational result is NO GO. No material operational river limitation is currently identified. Only this category can produce an overall NO-GO.
A favorable daylight fishing-weather window is available and no material operational limitation is identified. This combines practical weather and usable-window quality without redefining them as safety hazards.
Water temperature and the forecast daytime high are within Dive Otter's preferred operating season. Dive Otter Season combines a preferred water-temperature boundary of 55 °F or warmer with a preferred forecast daytime-high range of 55–90 °F. These are outfitter operating preferences, not a statement that fish cannot be caught outside them.
Productivity asks whether the combined environmental state supports a worthwhile fishing opportunity. The decision is driven by recognized hydrologic and biological patterns, including river level and trajectory, runoff and turbidity, water temperature, dissolved oxygen, and thermal or oxygen stress.
Direction describes whether the environmental situation appears to be improving, stable, deteriorating, or becoming uncertain.
Confidence describes the completeness and freshness of the evidence supporting the recommendation. It does not predict whether fish will bite.
River Conditions
Typical · Stable
Current river-state analysis is included in the fishing outlook. Detailed monitoring, seasonal baselines, and historical comparisons are maintained separately.
Typical · Stable
View River Analysis
Fishing Evidence
What Is Shaping the Outlook
Each section repeats one of the six decisions above,
then shows the evidence used to reach it. Supporting
Context preserves additional observations that do not
currently change a decision.
Absolute Mainstem Flow
745 cfs · Normal
Neutral
South Elgin discharge is within the provisional normal operating range.
How this is evaluated
At or below 2,100 cfs
Neutral
Above 2,100 and below 2,800 cfs
Neutral
2,800 to below 3,200 cfs
Caution
3,200 cfs or greater
Safety
Current Wind
0 mph
Favorable
Observed sustained wind.
How this is evaluated
Below 15 mph
Favorable
15 to below 30 mph
Unfavorable
30 mph or greater
Safety
Maximum Gust · Next 24 Hours
8 mph
Favorable
Maximum forecast wind gust during the next 24 hours.
How this is evaluated
Below 25 mph
Favorable
25 to below 35 mph
Caution
35 mph or greater
Unfavorable
Thunder Risk · Next 24 Hours
2%
Favorable
Maximum numerical thunder probability represented during the next 24 hours. Forecast wording and timing are also considered.
How this is evaluated
Below 20% across the broader forecast
Favorable
20% or greater somewhere in the next 24 hours
Caution
30% or greater within the next three forecast hours
Unfavorable
Current thunder or severe warning
Safety
Storm Timing
No near-term storm timing identified
Favorable
No material weather hazard is currently identified.
How this is evaluated
Storm potential later in the next 24 hours
Caution
Storm potential within the next three hours
Unfavorable
Current thunder or severe warning
Safety
Current Weather Hazard
Clear
Favorable
Current thunderstorms and severe weather can override otherwise favorable fishing conditions.
How this is evaluated
CLEAR or RAIN_POSSIBLE
Favorable
STORM_POSSIBLE
Caution
STORM_IMMINENT
Unfavorable
STORM_ACTIVE or SEVERE_WEATHER
Safety
Cold-Water Immersion
76.5 °F · Normal
Favorable
The available upstream water-temperature estimate is above the model cold-water advisory threshold. Temperature is an upstream McHenry estimate rather than a measurement within the St. Charles Pool.
Maximum Wind · Next 24 Hours
5 mph
Favorable
Maximum sustained wind represented during the next 24 hours. Individual forecast hours are evaluated when selecting the weather window.
How this is evaluated
Hourly wind below 10 mph
Favorable
Hourly wind from 10 through 15 mph
Caution
Hourly wind above 15 mph
Unfavorable
Thunder Risk · Next 24 Hours
2%
Favorable
Maximum numerical thunder probability represented during the next 24 hours. Forecast wording and timing are also considered.
How this is evaluated
Below 20% across the broader forecast
Favorable
20% or greater somewhere in the next 24 hours
Caution
30% or greater within the next three forecast hours
Unfavorable
Current thunder or severe warning
Safety
Recommended Window
Thu 6:00 AM – 6:00 PM
Favorable
This is the longest continuous daylight period in the next 24 hours without a material operational weather limitation.
How this is evaluated
Longest continuous GOOD daylight period
Favorable
If none exists, longest continuous CAUTION daylight period
Caution
POOR and NIGHT periods are excluded
Unfavorable
Window Length
12 hours
Neutral
Continuous forecast hours included in the selected daylight weather window.
Preferred-Season Water Temperature
76.5 °F
Favorable
Water temperature is current and is used to evaluate Dive Otter's preferred mixed-species kayak-fishing season. Evidence: CURRENT (0.9 hours old).
How this is evaluated
Below 55 °F
Unfavorable
55 °F or greater
Favorable
Daytime Comfort Forecast High
79 °F
Favorable
The forecast high is used as a day-level boundary for Dive Otter's preferred operating season. It is an outfitter preference, not a universal fishing, biological, or heat-safety threshold.
How this is evaluated
Below 55 °F
Unfavorable
55 to 90 °F
Favorable
Above 90 °F
Unfavorable
Mainstem flow
Typical
Neutral
Seasonal flow position used by the productivity pattern model.
Mainstem trend
Stable
Neutral
Recent river trajectory used to distinguish active from recovering high water.
Turbidity
Typical
Favorable
Seasonal turbidity position used with runoff and river conditions.
Local runoff
Typical Or Low · Stable
Neutral
Tributary state and direction used to identify runoff-driven conditions.
Water Temperature
76.5 °F
Favorable
The upstream McHenry temperature proxy is evaluated as biological context in addition to its seasonal position. The screening points are not hard physiological limits for smallmouth bass.
How this is evaluated
Below 80 °F
Favorable
80 °F or greater
Neutral
84 °F or greater together with critically low oxygen
Unfavorable
Dissolved Oxygen
6.1 mg/L
Favorable
The upstream McHenry dissolved-oxygen proxy is evaluated separately from its seasonal percentile. It represents regional stress context rather than a current in-pool measurement.
How this is evaluated
5.0 mg/L or greater
Favorable
Below 5.0 mg/L
Unfavorable
Below 4.0 mg/L together with very warm water
Unfavorable
Combined Heat + Low Oxygen
Not triggered
Favorable
Warm water and low absolute dissolved oxygen must occur together.
How this is evaluated
80 °F or greater + oxygen below 5.0 mg/L
Unfavorable
Severe Thermal / Oxygen Stress
Not triggered
Favorable
Very warm water and critically low dissolved oxygen must occur together.
How this is evaluated
84 °F or greater + oxygen below 4.0 mg/L
Unfavorable
River Trend · Past 24 Hours
Stable
Neutral
The primary river trajectory used by the direction model.
How this is evaluated
FALLING or RAPIDLY_FALLING
Favorable
STABLE
Neutral
RISING or RAPIDLY_RISING
Unfavorable
Tributary Trend
Stable
Neutral
Whether local runoff is increasing, falling, stable, or mixed.
How this is evaluated
FALLING
Favorable
STABLE
Neutral
MIXED
Caution
RISING
Unfavorable
Forecast Rain · Next 24 Hours
0.00 in / 24h
Favorable
Forecast rainfall is evaluated together with river trajectory.
How this is evaluated
Below 0.50 in
Neutral
0.50 to below 0.75 in while mainstem is improving
Caution
0.75 in or greater
Unfavorable
Primary mainstem flow
Fresh
Favorable
Supporting aquatic observations
7 fresh
Favorable
Current weather observation
Complete · 20 minutes old
Favorable
A fresh current wind observation and supporting station data are available.
Hourly weather forecast
Available
Favorable
Missing major inputs
None
Favorable
Rain in Next 72 Hours
0.00 in
Neutral
Longer-range rainfall context. The current model does not apply an independent 72-hour rainfall threshold.
How this is evaluated
Cloud Cover · Next 24 Hours
49%
Neutral
Average forecast cloud cover during the next 24 hours.
How this is evaluated
Below 65%
Neutral
65% or greater
Neutral
Pressure Change · 3 Hours
-0.34 hPa
Neutral
Observed short-term barometric-pressure movement.
How this is evaluated
Recent Pressure Trend
Stable
Neutral
Recent observed pressure behavior.
How this is evaluated
FALLING + precipitation
Neutral
FALLING + cloud cover at or above 60%
Neutral
Pressure Change · 6 Hours
+0.34 hPa
Neutral
Broader observed pressure movement when a usable comparison is available.
How this is evaluated
Background Pressure Trend
Stable
Neutral
Longer-duration pressure behavior retained as atmospheric context.
How this is evaluated
Atmospheric Transition
Not triggered
Neutral
The combination required for the atmospheric-transition context pattern is not currently present.
How this is evaluated
Recent pressure FALLING + precipitation
Neutral
Recent pressure FALLING + cloud cover at or above 60%
Neutral
About the Fishing Outlook
How the Recommendation Is Built
The fishing outlook does not use a single numerical score.
It evaluates safety, practical trip conditions, Dive
Otter season availability, productivity, direction, and
evidence quality as separate decisions.
Safety alone can produce a No-Go. Poor comfort, a limited
season, an unfavorable productivity outlook, or the lack
of a fully favorable weather window can make the overall
outlook Marginal without labeling the trip unsafe.
Direction describes whether conditions appear to be
improving, stable, deteriorating, or uncertain. Confidence
describes the completeness and freshness of the evidence;
it does not predict whether fish will bite.
