PrimeBite Fishing
Largemouth Bass
Research & Methodology
Largemouth Bass — Research & Methodology
Last updated: 2026-03-12
This page documents the current live Largemouth Bass profile, the open-access URLs behind each driver, verbatim quotes, and what is research-backed vs calibrated. We keep proprietary calibration details private.
On this page
How It Works
The Largemouth Bass profile uses the current Bass v2 structure: a day baseline plus an hourly activity curve. Unlike Walleye and Muskie (which use solunar window positions), Bass ratings are driven by environmental conditions: dawn/dusk timing, wind speed, water temperature, seasonality, and a small moon phase effect.
Rating Structure
- Day baseline (1.0–5.0): Represents the broader day setup before the exact hour is applied. It comes from seasonality, water temperature, moon phase, and a small built-in starting day level.
- Hourly activity curve: Shows how the rating changes throughout the day after dawn/dusk timing and hourly wind move the score up or down. Peaks are typically near dawn and dusk, with softer midday hours.
- Compact app headline: The single Bass headline number in the app is the best contiguous 2-hour average, not a simple all-day average.
- Best Times: Identifies the strongest windows from the hourly curve, typically around Dawn and Dusk.
What Drives the Rating
- Dawn/dusk proximity — Primary driver. Bass are most active near sunrise and sunset.
- Wind speed — Quadratic dome: optimal around 12 km/h (~7.5 mph). Both calm and high wind reduce catch rates.
- Water temperature — Dome: optimal 20–24°C (68–75°F). Estimated from 7-day air temperature history.
- Seasonality — Summer peak (June–July), winter trough (December–February).
- Moon phase — Small, conservative effect. Telemetry-only evidence; not a strong direct CPUE signal for Bass.
What Is NOT Used
- Barometric pressure — Two independent studies found no significant effect (p>0.05).
- Cloud cover / light intensity — Not significant in qualifying study.
- Solunar window positions (overhead/underfoot) — No bass-specific evidence found after comprehensive search.
Study Limitations
- Mixed methods: Some sources use electrofishing CPUE or telemetry, not recreational angling CPUE. Effect directions are supported, but exact magnitudes may differ for hook-and-line fishing.
- Moon phase: Evidence is telemetry-only (activity/depth shifts), and patterns are not consistent across the year. Included with very small weight.
- Water temperature: Estimated from air temperature history (7-day exponential decay model). Accuracy ~1–3°C. No free freshwater lake temperature API exists.
- Regional variation: Optimal temperatures and seasonal patterns may differ by latitude and lake type.
Ratings are relative indicators, not guarantees. Do not assume they apply universally. We use the evidence-backed direction of effects and calibrate magnitude for a stable 1–5 scale.
Variables
Every variable is classified as research-backed, calibrated, or excluded.
| Variable | Status | Evidence | Notes |
|---|---|---|---|
| Dawn/dusk influence | Research-backed | BASS-S5 (p<0.0001), BASS-S1 | Primary driver. Electrofishing CPUE + telemetry confirm crepuscular peaks. |
| Wind speed | Research-backed | BASS-S6 | Quadratic dome. Optimal ~12 km/h. AIC model selection supports inclusion. |
| Water temperature | Research-backed | BASS-S4 (p=0.0003), BASS-S7 | Dome. Peak 20–24°C. Estimated from air temp (no lake temp API). |
| Seasonality | Research-backed | BASS-S5, BASS-S1 | Summer 3–4× winter activity. Monthly multipliers are calibrated shape. |
| Moon phase | Calibrated (direction-backed) | BASS-S2 | Telemetry shows lunar-linked shifts, but NOT consistent year-round. Small weight. |
| Barometric pressure | Excluded (null result) | BASS-S3, BASS-S8 | F=0.08/0.16 (BASS-S3); p>0.05 (BASS-S8). Not significant in either study. |
| Cloud cover / light | Excluded (null result) | BASS-S3 | F=1.10/0.65. Not significant. |
| Solunar windows | Excluded (no evidence) | N/A | No bass-specific open-access evidence found after 5 search sweeps. |
Key Quotes (Verbatim)
Dawn/Dusk — BASS-S1 (Hlina et al. 2026)
"Largemouth bass acceleration peaked during dawn (0.521 ± 0.012 m s⁻²) and slowly decreased throughout the day with acceleration being the lowest at night (0.278 ± 0.002 m s⁻²)"
— p.7–8, Results
Dawn/Dusk — BASS-S5 (McInerny & Cross 2000)
"Sample period F = 32.50, P < 0.0001 (< 120 mm TL); F = 55.91, P < 0.0001 (200-299 mm TL); F = 20.13, P < 0.0001 (≥ 300 mm TL)"
— Table 1, p.5
Wind — BASS-S6 (Maahs et al. 2022)
"We observed a quadratic effect of wind speed on bass weigh-in probability, with weigh-in probability being highest at wind speeds around 12 km/h"
— p.1522, Results
Water Temperature — BASS-S4 (Louisiana CPRA 2016)
"The model produces a dome-shape relationship between CPUE and temperature, with highest CPUE occurring between 20-24°C"
— p.7, Results
"Temperature Parameter Estimate = 0.3328, p = 0.0003; Temperature² = -0.00764, p = 0.0001"
— Table 2, p.7
Moon Phase — BASS-S2 (Hanson et al. 2008)
"The percent of lunar face shining and whether the moon was waxing or waning were significant determinants of swimming activity and depth distribution during most of the lunar cycles evaluated, although these patterns were not consistent across the year."
— p.1, Abstract
Barometric Pressure — Excluded (BASS-S3, BASS-S8)
"Analysis of variance of environmental parameters during good and poor runs" shows barometric pressure F = 0.08 (1973) and F = 0.16 (1974), both below F.05 critical values.
— BASS-S3, Table 4, p.132
Full Source List
| ID | Authors / Year | Title | Link |
|---|---|---|---|
| BASS-S1 | Hlina et al. 2026 | Seasonal effects on the acceleration of largemouth bass (Animal Biotelemetry) | |
| BASS-S2 | Hanson et al. 2008 | Effects of lunar cycles on activity patterns and depth use (Fisheries Mgmt & Ecology) | |
| BASS-S3 | Winter 1976 | Movements and behavior of largemouth bass — UMN thesis | |
| BASS-S4 | Louisiana CPRA 2016 | Largemouth Bass HSI Model (2017 Coastal Master Plan) | |
| BASS-S5 | McInerny & Cross 2000 | Seasonal and diel variation in electrofishing CPUE (MN DNR Report 451) | |
| BASS-S6 | Maahs et al. 2022 | Effects of limits on largemouth bass tournament capture (N. Am. J. Fish. Mgmt) | Article |
| BASS-S7 | Sylvia et al. 2020 | Bass behaviors and environmental conditions (Iowa State) | |
| BASS-S8 | Burkett 1981 | Hook-and-line vulnerability vs physicochemical parameters (EIU thesis) |
Changelog
- 2026-03-12: Updated wording to match the live Bass v2 app model: day baseline + intraday modifier, hourly curve, and best contiguous 2-hour headline summary.
- 2026-03-08: Initial release. 8 open-access sources. Environmental day rating with hourly activity curve. Calibrated using 6-step evidence-anchored process.