Issue 4, May 20, 2013

Modified Growing Degree Days (Base 50°F,  March 1 through May 16)

Station Location

Actual Temperature

Historical Average   (11 year)

One-Week Projection

Two-Week Projection

Freeport

261

297

333

412

St. Charles

278

285

344

417

DeKalb

275

328

353

438

Monmouth

317

375

401

488

Peoria

341

409

426

515

Champaign

373

411

463

559

Springfield

398

461

499

603

Brownstown

418

514

521

631

Belleville

437

540

544

657

Rend Lake

492

588

604

725

Carbondale

476

557

582

696

Dixon Springs

490

605

601

721

Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity.  In warm years, insects emerge earlier, like we experienced last spring. Degree day accumulations remain slightly behind, but high temperatures this last week have begun to get us closer to being on track with the historical average. 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 University of Illinois Department of Crop Sciences and the Illinois Water Survey). (Kelly Estes)

Author:
Kelly Estes

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