Winter Weather Alert – January 2026

By: Maria Smith, HCS-OSU

Cold is an obvious feature of our Ohio winters, but believe it or not, this month’s sustained cold is an anomaly not seen for nearly the past century. 

Although we’ve had pockets of damaging cold temperatures over the past week (Figure 1), tomorrow morning will be the most widespread and deepest of them all (Figure 2). 

Figure 1. Minimum temperatures for 24 Jan 2026. Note a pocket of tempertures between -5 to -15F in far-NE OH. Temperatures at the Kingsville AARS Research Station logged -9.4F on 24 Jan 2026. Data from https://newa.cornell.edu 

Figure 2. Forecast temperatures for 31 January 2026. Widespread temperatures well below 0F are expected across the state. 

Current bud hardiness models are estimating temperatures for Vinifera such as Chardonnay to have attained a hardiness to nearly -16F (Figure 3). What is interesting, according to the model, is that many of our cold-hardy hybrids are estimated to have less hardiness closer to -11 to -14F (Figure 3). We will show in a follow-up post that many cultivars did lose hardiness following the warm temperatures in early January, although we would expect to regain some hardiness with the recent sustained cold weather pattern

Figure 3. Predicted LT50 (estimated minimum temepratures at which we would expect to sustain 50% primary bud mortality) for Chardonnay (left) and Frontenac (right). 

Based on some initial estimates of injury following temps reaching -9.4F in Kingsville over the past week, I suspect the hardiness is likely over-estimated for Vinifera, at least. However, we will be monitoring injury rates and temperatures over the next several days and will provide more in-depth information once this sustained cold period has passed in the next week or two.

In the meantime, now is a good opportunity to review assessing grapevine winter injury prior to starting or resuming dormant pruning to determine needs for adjusted pruning and yield retention in the 2026 season.