OVERTONE
Wine Weather Intelligence
← All Posts

758 GDD: July Arrives With Heat Behind It

Willamette Valley — July 01, 2026

Where We Stand

Through July 1, the season has accumulated 758 GDD (base 50F) across 92 days since April 1. This past week added 74 GDD — a modest contribution reflecting a week that topped at 70F and bottomed at 48F, with 0.71 inches of precipitation. Bud break came April 4. Bloom was concentrated around June 2. The vines are 29 days out of bloom and tracking through what the platform's phenology data places firmly in post-bloom development.

The Week Ahead

Models show seven consecutive dry days. Highs move from 70F on July 2 up through 81F, 85F, and 86F midweek before easing back to 79F by July 8. No precipitation is indicated across the entire window. That's a clean, accelerating heat accumulation curve arriving at a point in the season when berry development is actively underway. The shift from the cooler, wetter week just closed to a dry run topping at 86F is abrupt. The swing from this week's low of 48F to forecast highs in the mid-80s represents the kind of diurnal compression that changes how fast GDD accumulates relative to what the calendar suggests.

Season Context

At 758 GDD on day 92, the season is carrying meaningful heat. The bloom date of June 2 was early enough to put the valley in a reasonable position entering July, and a dry forecast through at least July 8 removes near-term disease pressure from the equation. What the next seven days establish in terms of additional accumulation will shape how much margin exists heading into what is historically the most consequential stretch of the Willamette summer. The pace of GDD gain through mid-July is worth tracking against where the season lands at the end of this coming week.

Season GDD Tracker

0217435653871 Apr 01Apr 16May 01May 16May 31Jun 15Jun 30 758 GDD 2026 Cumulative GDD (Base 50F)
Cumulative Growing Degree Days (base 50F, cap 86F) from April 1. Willamette Valley, Oregon.

7-Day Outlook

Wed
Jul 01
70°
52°
Thu
Jul 02
75°
49°
Fri
Jul 03
81°
53°
Sat
Jul 04
🌤
85°
52°
Sun
Jul 05
86°
46°
Mon
Jul 06
85°
51°
Tue
Jul 07
79°
46°
This week at a glance: High 70F · Low 48F · 0.71" precip · 74 GDD accumulated · Season total: 758 GDD
Get the forecast in your inbox
Weekly wine weather intelligence for the Willamette Valley. Free.