Hill County, Montana / Spring Wheat

Total GDD: 3191 (Jul 31)

Day 108 / 108 (100%)

Current Season

Total GDD: 3191 (Jul 31)

Method: 32°F

7-Day Daily Avg: 40.6

7-Day Projection: 3475 by Aug 07

Season: Apr 15, 25 - Jul 31, 2025

Key Freeze Dates (32°F)

Last Freeze:
10%: 04-30
50%: 05-15
90%: 05-23

First Freeze:
10%: 09-10
50%: 09-12
90%: 09-13

Growing Degree Days (GDD) track heat accumulation to predict when plants reach growth stages, pests emerge, and diseases become active.

Thresholds mark specific GDD values when events typically occur, with crossing dates showing when your season reaches each milestone.

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Thresholds & Notes

Planting Window (GS00) 630 °D

May 15, 2025 | May 19, 2024 | May 15, 2023

Growth Stage

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Big Sandy optimal seeding window. Target 90 lbs/acre for dryland Montana wheat.

Emergence (GS10) 815 °D

May 24, 2025 | May 28, 2024 | May 22, 2023

Growth Stage

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Coleoptile emergence. Scout for wireworms in northern Montana soils.

Three Leaf (GS13) 1030 °D

May 31, 2025 | Jun 5, 2024 | May 28, 2023

Growth Stage

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Main shoot plus 2 tillers. Broadleaf herbicide window for Montana spring wheat.

First Node (GS31) 1290 °D

Jun 10, 2025 | Jun 14, 2024 | Jun 5, 2023

Growth Stage

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Stem elongation begins. Apply second nitrogen split Big Sandy dryland wheat.

Flag Leaf Ligule (GS39) 1640 °D

Jun 19, 2025 | Jun 26, 2024 | Jun 15, 2023

Growth Stage

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Flag leaf fully emerged. Stripe rust scouting critical Montana wheat belt.

Heading (GS55) 1940 °D

Jun 29, 2025 | Jul 5, 2024 | Jun 26, 2023

Growth Stage

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Half of inflorescence emerged. Wheat midge threshold Big Sandy area.

Anthesis (GS65) 2090 °D

Jul 3, 2025 | Jul 9, 2024 | Jun 30, 2023

Growth Stage

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Flowering mid-ear. Fusarium head blight fungicide window Montana wheat.

Milk Development (GS73) 2340 °D

Jul 9, 2025 | Jul 15, 2024 | Jul 7, 2023

Growth Stage

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Early milk stage. Montana spring wheat kernel filling rapidly.

Soft Dough (GS85) 2540 °D

Jul 14, 2025 | Jul 19, 2024 | Jul 12, 2023

Growth Stage

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Grain content soft. Preharvest herbicide timing Big Sandy wheat fields.

Hard Dough (GS87) 2740 °D

Jul 20, 2025 | Jul 24, 2024 | Jul 17, 2023

Growth Stage

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Fingernail impression held. Direct harvest Montana spring wheat 14% moisture.