Linfield University Wine Studies Reports

Document Type


Publication Date



This report describes the impacts of climate and phenology on vintage for the North Willamette Valley in Oregon in 2019. A relatively mild early winter in 2018 was followed by a cold and wet second half of winter in 2019 and then a wet, but warm, spring. The growing season saw a few mild frosts during late April, but started off warmer than average, moderating through mid-vintage with fewer than average heat spikes. Near-record precipitation amounts during late June and early July brought increased disease pressure to the region. The vintage will be remembered for the early rains in September and rapid cool-down into October, which challenged harvesting decisions. Degree-day totals for 2019 ended up similar to 2012 and 2018, marked by the lowest heat accumulation experienced in September and October since 2007. Phenological timing and interval lengths were similar to observations in 2018 averaging April 16th for bud break, June 8th for bloom, August 14th for véraison, and September 27th for harvest. The cool vintage came largely from substantially lower maximum temperatures while minimum temperatures were near average to slightly above average. This was largely the result of higher humidity levels, which also brought greater disease pressure.


This report was made possible by data provided by Results Partners and the participating vineyards.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.