After a severe hailstorm at Fort Ellis, Montana, an experienced hail insurance adjuster estimated 90–100% damage in replicated yield plots of barley (Hordeum vulgare L.). After harvest, grain yield losses for all 66 entries in the nursery were found to range from 26 to 84%. A group of 11 cultivars selected for further study averaged 55% less than normal yield with a range of 29–82%. Yield and heading date were significantly (P < 0.05) correlated for all cultivars (r = 0.39*, n = 42), within six-rowed cultivars (r = 0.79*, n = 7), and for the 11 selected cultivars (r = 0.62*, n = 11). Although there was no significant correlation between yield and heading date within two-rowed cultivars, a group of two-rowed early isogenics was significantly reduced in grain yield compared to their late counterparts. The number of days between heading and time of hail damage was a better indicator of final yield loss than number of culms remaining (the criterion used for hail-adjuster estimates of damage). Regrowth is more likely to occur in barley if the hail damage is near or before heading time rather than 5–15 days after heading. Therefore, the positive correlation in this test between late heading date and yield is because the later entries had just headed out when the hail came, while the low yielding entries headed 10–15 days before the hailstorm.