Weather and climate conditions this week in Wisconsin
Here are this week’s take-home points about the weather. Scroll down for the full downloadable report.

Current Wisconsin weather and climate conditions
- An active May 20-21 brought 2” or more for some, especially in the SE. This was a switch from the first part of May, where most of the state had 3 days or less with measurable precip. Overall, most of the state has had a drier-than-normal May.
- Temperatures were unseasonably chilly last week, with most locations in the state reporting 8-10ᵒF below normal for average temps including a few nights with lows in the 30ᵒF’s.
Impact
- Soil moisture conditions showed widespread improvement from last week, with a large portion of the state estimated to have wetter-than-normal soils. Several Wisconet stations showed moisture gains following the precip last week.
- Rains in the southeast lead to 1 class improvements in drought severity in that region.
- Corn and soybean emergence made big gains from last week (52% & 42% complete, respectively), with planting nearing completion (Source: NASS).
Outlook for Wisconsin weather and climate
- Overnight frost/freeze risk is non-existent this upcoming week. Climatologically speaking, the odds for a frost/freeze after this week are very slim.
- Multiple rain chances throughout the state for the next 7 days, with the highest chances in the NW.
- Early June climate probabilities are leaning towards warmer and wetter than normal. The remainder of June is also leaning towards warmer-than-normal, with uncertainty for precip (equal chances).
Agronomic considerations
- Field Work and Conditions
- Avoid trafficking fields in moist conditions to prevent compaction with recent heavy precipitation.
- See these considerations for early season corn management.
- Manure Applications
- Reminder of Wisconsin’s NR 151 Runoff Rules with the timing of manure spreading and current runoff levels. Check DATCP Runoff Risk Advisory Forecast.
- Pest Management
- Scout fields to note which weed species are emerging.
- As corn and soybean crops emerge, note growth stages to time future applications and sampling.
- While slug issues have not been as severe this year, UW is monitoring populations weekly across the state with SlugNet.
- Be observant of black cutworm and true armyworm moths migrating to the state. Check trap catches in your region with the DATCP Pest Survey. Sign up for insect pest alerts specific to your region.
- Reports of black cutworm have started, and the window of damage is beginning. Begin scouting for signs of feeding as soon as corn plants emerge.
- Forage Management
- Continue scouting for alfalfa weevil as alfalfa stands grow.
- Many alfalfa stands in Southern WI have been harvested. See first harvest considerations here.
- Small Grains
- Reminder to properly stage small grains such as winter wheat, as many herbicides cannot be applied after Feekes 5.
- Scout for stripe rust and any early signs of disease with recent cool and wet weather.
- Fusarium Head Blight risk is low across the state but consider this reminder about spraying fungicides. Scab alerts and risk forecast can be found here.
- Specialty crops- Vegetables
- Be on the lookout for purple spot in asparagus. The recent wet and cool conditions promote the release of spores from infected residue from last season.
- Common asparagus beetle populations are still at damaging levels in northern WI and along Lake Michigan. If you have had problems before, make sure to scout the edges of those fields in the afternoon when these beetles are most active.
- The first generation of seed corn maggot have emerged and the second generation is starting to enter the southwest corner of the state. Mated females will begin laying eggs in southern WI in the next 10-12 days. Risk will be high in southern WI during the first week of June. Onion maggot continues to progress across the state with the greatest severity in northern and central WI. Cabbage maggot severity is high across most of the state. Adults are attracted to areas of high organic matter such as a recently tilled field or areas of high residue to lay eggs. If possible, incorporate residue or apply organic fertilizer at least 2 weeks prior to planting to reduce the attractiveness.
- Cucurbit growers may consider a kaolin clay drench of trays before transplanting as a mechanical barrier and repellant to reduce cucumber beetle feeding.
- Start scouting for Colorado potato beetle on potatoes and eggplant. Adults and initial egg masses have been detected in the southwest and southern WI will start seeing more in the next week.
- Cover eggplant with row cover immediately after transplanting to prevent damage from Colorado potato beetle and flea beetles. Keep the plants covered until they recover from transplant shock and start growing vigorously. Remember to remove when flowering!
- Specialty Crops- Fruit
- Wisconsin fruit growers can reference the Midwest Fruit Pest Management Guide for a list of registered products and recommended best practices. View the MFPMG Online or order a hard copy here: MFPMG Hard Copy.
- Apple growers can reference the NEWA weather station network to monitor disease infection events for apple scab and fire blight. Make sure to keep track of green tip and petal fall dates. Check out your nearest weather station: NEWA Weather Station Network (Cornell).
- Codling moth have been captured in Southern WI. Make sure to check traps after warm, calm evenings to establish a biofix date. Biofix occurs when ~5 or more moths are captured in one evening or captured across consecutive nights. First generation larvae will emerge after ~250 degree-days base 50ᵒF from the biofix date.
- Keep track of degree-days (base 50ᵒF) from petal fall to determine the end of plum curculio movement into the orchard. Plum curculio will continue movement into the orchard until ~308 degree-days base 50ᵒF have accumulated from petal fall.
- Recent rain events have driven infection periods for grape diseases. Grape growers may consider reviewing grape phomopsis monitoring and management.
- Grape growers can reference the NEWA weather station network to monitor disease infection events for phomopsis, powdery mildew and black rot. Check out your nearest weather station: NEWA Grape Diseases Model.
- Strawberry growers may consider reviewing scouting and management strategies for thrips, tarnished plant bug and mites.
If you would like to obtain a PowerPoint copy of this report, please email rue.genger@wisc.edu.