Issue 3, May 14, 2018

Modified Growing Degree Days (Base 50°F, March 1 through May 13)

Station Location

Actual Total

Historical Average (11 year)

One- Week Projection

Two-Week Projection

Freeport

252

267

323

398

St. Charles

267

258

333

402

DeKalb

233

296

310

391

Monmouth

322

339

407

491

Peoria

343

372

430

515

Champaign

371

373

461

552

Springfield

461

419

561

662

Perry

471

402

562

652

Brownstown

443

470

545

651

Belleville

476

495

582

692

Rend Lake

506

540

617

733

Carbondale

475

513

578

688

Dixon Springs

537

559

647

762

Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. Home, Yard, and Garden readers can use the links below with the degree day accumulations above to determine what insect pests could be active in their area.

GDD of Landscape Pests
GDD of Conifer Pests

Degree day accumulations calculated using the Illinois IPM Degree-Day Calculator (a project by the Department of Crop Sciences at the University of Illinois and the Illinois Water Survey). (Kelly Estes)

Author:
Kelly Estes

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