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Warming Into It: Willamette Valley Week 15

Willamette Valley — April 15, 2026

Where We Stand

Bud break recorded April 4. Forty-six days into the season, cumulative GDD through April 15 sits at 72 base 50F. This past week added 18 of those degree days against a high of 71F and a low of 39F, with 2.09 inches of precipitation. The vines are in pre-bloom phase — still early, but the thermal accumulation is moving. That combination of a 32-degree diurnal swing and meaningful soil moisture is the texture of mid-April in the Willamette: not hostile, not generous, just conditional.

The Week Ahead

The 7-day forecast opens wet — 0.93 inches expected on day one, a trace of 0.1 inches on day two, then nothing through the back half of the week. Highs climb from 48F to a peak of 71F by day six before pulling back to 62F on day seven. That arc matters. The front end of the week absorbs the moisture from last week's pattern and clears it. The back half, with highs pushing into the mid-to-upper 60s and low 70s under likely dry conditions, is where GDD accumulation accelerates. Models suggest meaningful heat addition over the second half of this 7-day window.

Season Context

At 72 cumulative GDD on April 15, the season is neither aggressive nor behind — it is measured. Bud break on April 4 places the vine in a position where the warming forecast arrives at a reasonable moment, before the canopy has committed to rapid elongation. Historically, the Willamette's April pattern tends to front-load its precipitation and release into drier, warmer conditions by late month. The current forecast is consistent with that structure. What the next two weeks will determine is whether this warming holds or whether the marine layer reasserts — the late-April and early-May thermal record will define how much cushion the season carries into the critical June window.

The number to track from here is how quickly cumulative GDD closes the gap toward 150 as the forecast warming plays out.

Season GDD Tracker

020416282 Mar 01Mar 08Mar 15Mar 22Mar 29Apr 05Apr 12 72 GDD 2026 Cumulative GDD (Base 50F)
Cumulative Growing Degree Days (base 50F, cap 86F) from April 1. Willamette Valley, Oregon.

7-Day Outlook

Wed
Apr 15
🌧
48°
39°
0.93"
Thu
Apr 16
🌦
53°
36°
0.1"
Fri
Apr 17
57°
39°
Sat
Apr 18
65°
38°
Sun
Apr 19
68°
47°
Mon
Apr 20
71°
48°
Tue
Apr 21
🌦
62°
47°
0.01"
This week at a glance: High 71F · Low 39F · 2.09" precip · 18 GDD accumulated · Season total: 72 GDD
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