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Pennsylvania

Lake Wilhelm

Lake Wilhelm covers 1,567 acres of Pennsylvania's Mercer County, where largemouth follow cover, baitfish, and seasonal cooling.

Surface
1,567acres
Primary species
Largemouth
§ 01Today on the water · Lake Wilhelmvia Open-Meteo · 08:45 local
Air temp
70.6°F
Barometric
29.96″
↓falling 24h(-0.10)
Wind
5mph
from S
Moon
Waning Gibbous
day 19.4 · 77% lit

Air conditions sampled near the lake center, not measured on the water · refreshed ~15 min

§ 03Next 3 daysvia Open-Meteo · interpretation
  1. 1
    sepTue

    Stable window

    hi 91° · lo 70°

    Anytime through the day. Quiet weather day; lean on seasonal pattern and structure.

    ── light sw wind · settled

  2. 2
    sepWed

    Tougher window

    hi 92° · lo 69°

    Pick the calmest hour and stay flexible. Conditions push hard today; bite likely shrinks. Plan around the calmest gap.

    ── heavy precipitation · bite likely shrinks

  3. 3
    sepThu

    Better early

    hi 87° · lo 69°

    Pre-dawn through 9am. Get on the water before the front; the bite likely shrinks once precip starts.

    ── front rolling in · w wind setting up

§ 04Field notesPennsylvania

Where it is

Lake Wilhelm sits in Mercer County, Pennsylvania, covering about 1,567 acres. Where the largemouth sit changes with the season, not the map.

Seasonal pattern

Spring. Warming water pulls largemouth toward shallow, protected areas where they stage and spawn; the quickest-warming pockets lead.

Summer. Heat pushes fish off the shallows toward depth and shade; work the cooler ends of the day.

Fall. As water cools, forage and bass return toward shallower water; movement is wide, so covering water pays.

Winter. Cold water settles fish deep and slow; patience and a subtle presentation are the more dependable choice.

Key structure

  • Creek and cove mouths that funnel fish and bait
  • Weed edges and the clean lines along them
  • Inside turns where a bank changes angle
  • Submerged wood, brush, and laydown cover

The calendar decides which of these is worth time on a given day.

Forage

Bass on Lake Wilhelm key on baitfish and panfish; the productive water moves with the forage through the year.

Access

Launches around Lake Wilhelm are public; confirm seasonal closures and water levels with local sources first.

Regulations

Check current state and local regulations before fishing; limits and seasons can change.

§ 05Sources & field guides

Field guides

Data & references

  • Today's conditions — Open-Meteo, refreshed every ~15 min
  • Moon phase — local astronomical calculation, no external API
  • Lake area, depth, structure — Identity, surface area, coordinates and county/state are from the ProjectD canonical waterbody index (snapshot conus-20260518-v1, group gnis:01200001). Maximum depth and regulation links were not available from an acceptable source and are intentionally omitted.
  • Regulations — verify current state and local regulations before fishing

Last revised · Back to Lake Guide