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Cold Hold: Willamette Valley Week 13, 2026

Willamette Valley — April 01, 2026

Where We Stand

Through April 1, cumulative GDD stands at 29 — base 50F — on day 32 of the season. The week just closed delivered a high of 63F against a low of 30F, with 0.49 inches of precipitation and zero GDD added to the season total. That low of 30F is the number that defines this week. Bud break was recorded April 4, which means the vines are now carrying exposed tissue through a period that has already seen sub-freezing overnight temperatures. The season is open, but thermal accumulation has been effectively flat.

The Week Ahead

Models show a transition unfolding across the next seven days. The first two days carry the bulk of incoming precipitation — 0.93 inches followed by 0.10 inches — with forecast highs of 48F and 53F. After that, skies clear and the temperature trend builds steadily: 57F, 65F, 68F, 71F, before easing back to 62F on day seven. Precipitation for those final five days is essentially zero, with only 0.01 inches on the last day. The 71F high mid-week represents the warmest reading in the near-term record, and that four-day clear, warm stretch will contribute meaningfully to GDD accumulation after a week that added nothing.

Season Context

A cumulative GDD of 29 at this point in the season reflects a slow thermal start. The pattern so far — cold nights, variable precipitation, limited heat accumulation — is consistent with a season running behind a pace that would support early phenological development. Bud break has occurred on schedule, but the GDD base to support it has not yet built. The incoming warm stretch is the first real accumulation window of the season. How that stretch performs against the remaining April forecast will be worth tracking closely, particularly whether nighttime temperatures continue to moderate or hold near the threshold that defined this past week.

The relationship between the early bud break date and the shallow GDD foundation is the central tension in the season right now.

Season GDD Tracker

0255075100 Mar 01Mar 06Mar 11Mar 16Mar 21Mar 26Mar 31 29 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 63F · Low 30F · 0.49" precip · 0 GDD accumulated · Season total: 29 GDD
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