Summertime heat continues on this late May spring day on Tuesday in Manitoba. Temperatures are climbing across the Prairies under a ridge of high pressure over the region, effectively creating a heat dome for the next several days. Daytime highs across most of southern Manitoba, including Winnipeg and Brandon, will reach the mid to upper 20s Tuesday afternoon. A yellow warning for heat is in effect for much of southern Saskatchewan, where temperatures are even hotter Tuesday. Environment and Climate Change Canada said the core of the warmest air will shift east in Manitoba throughout the week. Indeed, temperatures Wednesday will once again climb into the upper 20s in the sunshine in southern Manitoba, before catapulting into the mid-30s on Thursday and Friday. Those mid-30s highs coupled with warm overnight lows in the 20s later this week will likely trigger heat warnings here. But whether a heat warning is in effect or not, take proper precautions in this unseasonably warm weather, which will continue at least into early next week. Meanwhile, northwestern Ontario will enjoy sunshine and mid-20s highs on Tuesday, without the showers and thunderstorms that crossed the region on Monday. Warm temperatures in the upper teens and low 20s in the sunshine will extend well into northern Manitoba on Tuesday, too. The lone holdout is Churchill, where north winds will hold the community to a high of 5 C under a mix of sun and cloud.