Climate change may result in increasingly frequent extreme events, such as the unusually dry conditions that occurred in Germany during the apple growing season of 2018. To assess the eﬀects of this phenomenon on dormancy release and ﬂowering in apples, we compared irrigated and non-irrigated orchard blocks at Campus Klein-Altendorf. We evaluated bud development, dormancy release and ﬂowering in the following season under orchard and controlled forcing conditions. Results showed that irrigated trees presented longer (39.2%) and thinner shoots compared to non-irrigated trees. In both treatments, apical buds developed a similar number of ﬂower primordia per cyme (4–5), presenting comparable development and starch dynamics during dormancy. Interestingly, buds on non-irrigated shoots exposed to low chill levels responded earlier to forcing conditions than those on irrigated shoots. However, chill requirements ( extasciitilde50 Chill Portions) and bud phenology under ﬁeld conditions did not diﬀer between treatments. In spring, buds on non-irrigated trees presented a higher bloom probability (0.42) than buds on irrigated trees (0.30). Our ﬁndings show that mild water stress during summer inﬂuenced vegetative growth during the same season, as well as the response of buds to forcing temperatures and ﬂowering of the following season. The diﬀerences between irrigation levels in the phenological responses of shoots under low-chill conditions point to a so-far understudied impact of water supply on chilling requirements, as well as subsequent bud behavior. Accounting for the eﬀects of both the water status during summer and the temperature during the dormant season may be required for accurately predicting future tree phenology in a changing climate.