Milwaukee
Treat broadleaf57°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 3 – Oct 28
Wisconsin Weed Watch · updated Nov 3, 1:18 AM CT
When to apply pre-emergent in Wisconsin
Live soil temperatures for Milwaukee, Madison, Green Bay and Eau Claire, updated every three hours. Weeds sprout by soil temperature, not by the calendar, so the right week moves from year to year.
In Wisconsin, pre-emergent is a spring job: it stops crabgrass. Fall is seeding season here, so fall weed control means treating broadleaf weeds instead.
Spring pre-emergentNext season
Typically Apr 23 – May 17
Stops crabgrass and other summer weeds before they sprout.
Fall: no pre-emergentThis season
Treat broadleaf weeds Sep 1 – Oct 28
Fall is seeding season here, and pre-emergent would stop grass seed too.
Right now · fall (seeding season)
Treat broadleaf weeds now across Wisconsin
Soil is 54–57°F now. In fall, dandelions, clover and creeping Charlie pull sugars — and weed killer — down to their roots. Seeding this fall? Skip pre-emergent; it stops grass seed too.
Soil temperature by city
Soil 2 inches down, 5-day average: solid line = the last two weeks, dashed = the six-day forecast.
Madison
Treat broadleaf56°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 1 – Oct 24
Green Bay
Treat broadleaf55°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 1 – Oct 24
Eau Claire
Treat broadleaf54°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 1 – Oct 19
Wisconsin pre-emergent calendar
Spring pre-emergent stops crabgrass. The window runs from the typical day soil warms to 50°F to the day it holds 55°F, when crabgrass starts germinating (2016–2025). In fall Wisconsin lawns are in seeding season, so there is no fall pre-emergent; the window shown is for treating broadleaf weeds instead, from September until two weeks after soil usually cools to 55°F.
| City | Spring pre-emergent (crabgrass) | Fall (seeding season) |
|---|---|---|
| Milwaukee | Apr 23 – May 12 | None (seeding season) · treat broadleaf Sep 3 – Oct 28 |
| Madison | Apr 23 – May 10 | None (seeding season) · treat broadleaf Sep 1 – Oct 24 |
| Green Bay | May 6 – May 17 | None (seeding season) · treat broadleaf Sep 1 – Oct 24 |
| Eau Claire | Apr 25 – May 10 | None (seeding season) · treat broadleaf Sep 1 – Oct 19 |
These are typical-year dates (the median of 2016–2025); any one year can run a couple of weeks earlier or later, which is what the live readings above are for. For your exact yard, check soil temperature by ZIP.
What people in Wisconsin are identifying
We record the state each identification comes from. Wisconsin's list appears here once it has at least 40 identifications spread over 7 or more days — so no single scan stands out. Until then, see the national list, or add yours:
Identify a weed from a photoWeeds to watch in Wisconsin this fall
Questions about Wisconsin
When should I apply crabgrass pre-emergent in Wisconsin?
Put crabgrass pre-emergent down as soil warms to 50°F, before it holds 55°F and crabgrass starts germinating. In a typical year (2016–2025) that window is Apr 23 – May 12 in Milwaukee; Apr 23 – May 10 in Madison; May 6 – May 17 in Green Bay; Apr 25 – May 10 in Eau Claire.
Should I put down pre-emergent in the fall in Wisconsin?
Usually not. Fall is the best time to seed a cool-season lawn in Wisconsin, and pre-emergent stops grass seed as well as weeds. Fall is the time to treat broadleaf weeds such as dandelion, clover and creeping Charlie, once the summer heat breaks and while they are still growing.
What is the soil temperature in Wisconsin right now?
As of Nov 3, 1:18 AM CT: Milwaukee 57°F, Madison 56°F, Green Bay 55°F, Eau Claire 54°F (5-day average, about 2.4 inches down). Treat broadleaf weeds now across Wisconsin.
How the readings and dates are made, and their limits: Weed Watch method. Soil data: Open-Meteo.com (CC BY 4.0); typical dates: NASA POWER.