BirdTroutOpen the map When to fish the Oconto River, Wisconsin
June, July and August — those are the months with the most insects recorded from northern Wisconsin, 23 in June, 21 in July and 15 in August. Wisconsin DNR classifies it as Class II and Class III, managed as stocked and wild supplemented — that is the season and creel row to look up. The Oconto River averages 74.7 °F in July across 1 gauged stretch, so the middle of summer is a morning-and-evening proposition rather than a bad month.
What's likely in September
22 insects peak in September in northern Wisconsin. By month, not week.
Start with these — the patterns that match most of what is out now:
Mayflies
Blue-Winged Olive #16–22, Isonychia / Slate Drake #10–14, Little Yellow May #16–18, Trico #20–24
Tie onPheasant Tail Nymph nymph · Parachute Adams dry · Rusty Spinner dry
Caddis
October Caddis #8–10, White Miller #14–18, Green Rock Worm / Green Weenie #10–14
Tie onElk Hair Caddis dry · Prince Nymph nymph · Stimulator dry
Terrestrials
Cinnamon Flying Ant #16–20, Black Ant #14–20, Grasshopper #8–12, Leafhopper #18–22, Caterpillar #8–14
Tie onFoam Beetle terrestrial · Black Foam Ant terrestrial · Parachute Ant terrestrial
Crayfish, scuds and baitfish
Crayfish #4–8, Minnows + Dace #2–10, Sculpin #2–8
Tie onZonker streamer · Woolly Bugger (Black) streamer · Woolly Bugger (Brown) streamer
Worms, leeches and the rest
Water Boatman #14–18, Cranefly #6–10, Aquatic Worm #10–16, Damselfly #10–14, Dragonfly #4–10, and 1 more
Tie onWoolly Bugger (Olive) streamer · Walt's Worm nymph · Woolly Bugger (Brown) streamer
The hatch calendar
Insects peaking each month. Midges, scuds and sculpins are left out: they peak every month, so counting them would flatten the bars.
Every insect recorded here, by month (42)
| Insect | Months | Hook | Active at |
|---|---|---|---|
| Fish Eggs | October–January and April | #10–16 | 33–60 °F |
| Little Brown Stonefly | February–April | #12–16 | 38–50 °F |
| Blue-Winged Olive | March–May and September–November | #16–22 | 38–58 °F |
| Blackfly | April–June | #18–22 | 40–65 °F |
| Cranefly | April–June and September–October | #6–10 | 40–65 °F |
| Grannom | April–May | #14–16 | 48–58 °F |
| Green Rock Worm / Green Weenie | April–June and September–October | #10–14 | 45–68 °F |
| Hendrickson | April–May | #12–14 | 45–58 °F |
| Alderfly | May–June | #10–14 | 52–66 °F |
| Caterpillar | May–September | #8–14 | 55–75 °F |
| Crayfish | May–October | #4–8 | 55–78 °F |
| Giant Black Stonefly (Salmonfly) | May–June | #4–6 | 50–62 °F |
| Green Sedge | May–August | #12–16 | 48–64 °F |
| Light Cahill | May–July | #12–16 | 55–68 °F |
| Spotted / Tan Caddis | May–August | #14–18 | 55–70 °F |
| Sulphur | May–July | #14–18 | 52–68 °F |
| Black Ant | June–September | #14–20 | 55–80 °F |
| Brown Drake | June | #10–12 | 55–65 °F |
| Golden Stonefly | June–July | #6–10 | 55–68 °F |
| Gray Drake | June–July | #10–12 | 55–68 °F |
| Hex | June–July | #6–8 | 60–72 °F |
| Isonychia / Slate Drake | June–September | #10–14 | 55–70 °F |
| June Bug / Beetle | June–July | #10–14 | 58–75 °F |
| Leafhopper | June–September | #18–22 | 58–75 °F |
| Little Sister Caddis | June–August | #16–20 | 60–74 °F |
| Little Yellow May | June–September | #16–18 | 58–70 °F |
| Little Yellow Sally | June–August | #14–16 | 55–68 °F |
| Pale Morning Dun | June–July | #14–18 | 50–65 °F |
| Annual Cicada | July–August | #6–10 | 60–78 °F |
| Grasshopper | July–September | #8–12 | 60–80 °F |
| Trico | July–September | #20–24 | 58–72 °F |
| White Miller | July–September | #14–18 | 60–74 °F |
| Cinnamon Flying Ant | August–September | #16–20 | 58–78 °F |
| October Caddis | September–October | #8–10 | 45–58 °F |
| Water Boatman | September–November | #14–18 | 45–65 °F |
| Aquatic Worm | all year | #10–16 | 35–70 °F |
| Damselfly | all year | #10–14 | 55–78 °F |
| Dragonfly | all year | #4–10 | 55–78 °F |
| Leech | all year | #2–10 | 35–75 °F |
| Midge | all year | #18–24 | 33–75 °F |
| Minnows + Dace | all year | #2–10 | 35–78 °F |
| Sculpin | all year | #2–8 | 33–72 °F |
The season
Wisconsin publishes no season on this reach in the file this site reads. Wisconsin DNR classifies it as Class II, Class III, managed as stocked, wild supplemented, and that is the row to look up in the digest — the season and creel rules follow the classification rather than the river. What the state designates on this water → Wisconsin regulations →
Water temperature through the year
July is the warmest month and the one this site measures: 1 gauged stretch average 74.7 °F . Everything either side of July is colder than that.
More about Oconto River
Oconto River — live water temperature, regulations and access