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Pre-Bloom, High Heat, and a Cooling Trend on Deck

Willamette Valley — May 04, 2026

Where We Stand

Through May 4, the valley has accumulated 241 GDD (base 50°F), with 63 of those coming in just the past seven days. That single-week figure reflects what the thermometer confirmed: a high of 86°F paired with a low of 39°F — a 47-degree swing that compressed a lot of thermal work into a short window while keeping nights cold enough to slow vegetative momentum. Precipitation for the week was essentially nothing, 0.02 inches. Bud break was recorded April 4, putting us at day 34 of the active season, and the vines are currently in pre-bloom.

The Week Ahead

Models show a descending temperature profile over the next seven days: highs of 72°F, 76°F, 72°F, 68°F, 57°F, 67°F, and 75°F. Precipitation is forecast at trace levels — 0.01 inches on day five, nothing on the remaining six days. The mid-week dip to 57°F is meaningful in the context of where the vines are. Pre-bloom fruit development responds to accumulated warmth, and a single cooler day mid-sequence won't erase the week's gains, but the overall trajectory is a moderation from the 86°F spike rather than a continuation of it. The dry conditions hold throughout.

Season Context

241 GDD at day 34 reflects a season that has moved with purpose. The April 4 bud break date and the current pre-bloom status are consistent with that pace. The 86°F high this past week is the kind of reading that pulls the season forward in a concentrated burst — the question the coming weeks will answer is whether that acceleration holds or whether cooler temperatures moderate the path to bloom. The forecast pattern indicates a pause rather than a reversal. Bloom timing and the thermal conditions surrounding it are what the season now hinges on.

Season GDD Tracker

069138207277 Apr 01Apr 06Apr 11Apr 16Apr 21Apr 26May 01 241 GDD 2026 Cumulative GDD (Base 50F)
Cumulative Growing Degree Days (base 50F, cap 86F) from April 1. Willamette Valley, Oregon.

7-Day Outlook

Mon
May 04
72°
52°
Tue
May 05
🌤
76°
48°
Wed
May 06
72°
44°
Thu
May 07
68°
42°
Fri
May 08
🌦
57°
44°
0.01"
Sat
May 09
67°
48°
Sun
May 10
75°
45°
This week at a glance: High 86F · Low 39F · 0.02" precip · 63 GDD accumulated · Season total: 241 GDD
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