No-till farming (NT) is increasing in the Canadian Prairies in recent years because of the economic and environment benefits and its potential to sequester atmospheric carbon into the soil. Because surface residue and stubble act as insulation and impedes the exchange rate of thermal energy between the soil and the atmosphere, lower root-zone temperatures in the NT fields compared with that in the conventionally tilled (CT) fields were widely observed in the spring. Some studies found that low temperatures under NT persisted to the mid-season or throughout the whole growing season. Little attention, however, has been paid to the impact of the cooling effect of NT on the grain yield of wheat. The objective of this study was to investigate if NT could alleviate heat stress and benefit yield.