While July has been relatively pleasant, temperatures have [somewhat surprisingly] been largely below seasonal for much of the month. That’s all about to change as significant heat builds across the region to round out the month.

A developing southerly wind of 20-30 km/h this morning will draw warmer air northwards out of the United States and help push daytime highs up to around the 30°C mark. Skies will remain mainly sunny and humidity in the mid-teens should keep things feeling relatively comfortable. Expect lows to fall to around the 19°C mark tonight with winds continuing out of the south and partly cloudy skies.

Saturday will see a cold front slowly sweeping across the province, bringing with it a severe thunderstorm risk. Before that, though, there will be a hot summer day on tap with highs once again near the 30°C mark under mixed skies. With the southerly winds slowly diminishing and dew points rising to around 19 or 20°C, it will end up feeling quite humid in the afternoon. The cold front will progress eastwards through the day, reaching the Red River Valley mid- to late-afternoon. As it pushes into the valley, it will bring with it the risk of severe thunderstorms.

The primary threats with any storms that develop will be large hail and damaging winds, although with dew points so high, torrential rain is likely as well. They would move southeastwards through the Red River Valley. The biggest question will be whether or not storms actually develop. The threat will exist generally around the Trans-Canada Highway corridor and south, but we’ll provide an update on Saturday with a new look at the day’s potential.

The thunderstorm threat will diminish before midnight and temperatures will then drop to a low near 17°C under clearing skies.

Sunday will be another hot day with a high near 31°C but more comfortable humidity as the dew point drops back towards the mid-teens. Skies will be partly cloudy and winds will be light out of the east. Winds will shift out of the south on Sunday night and increase to 15-25 km/h, keeping temperatures fairly warm; the overnight low will be just around 19 or 20°C.

Long Range

Temperatures will continue to be warm through the start of next week with partly cloudy skies and highs generally around the 30°C mark. Monday will likely be moderately humid again, but things will dry out on Tuesday as a cold front moves through. The rest of the week looks fairly quiet with near-seasonal temperatures and low humidity.

The heat will be cranking up over the Prairies this week, and Winnipeg will see increasing warmth through the start of the week. A potentially stormy Tuesday will be a marked turning point as hot and muggy weather moves into the region. Heading into the second half of the week, conditions will be more settled but the heat sticks around for the foreseeable future.

A major pattern shift is underway that will bring a prolonged period of heat to much of western North America. Winnipeg will begin feeling the impact today as temperatures climb towards a high of 27°C under mixed skies. Winds will pick up out of the south-southeast to around 20 km/h in the afternoon as low pressure system begins approaching the province from Saskatchewan. The humidity will remain relatively comfortable today, though, with dew point temperatures expected to remain around 13 or 14°C.¹

Winds will continue out of the south-southeast tonight with temperatures remaining warm overnight; the expected low is just 17°C as a warm front pushes across the Red River Valley.

Summer will arrive in all forms for Winnipeg on Tuesday. Now in what’s known as the warm sector, the humidity will rise quite quickly on Tuesday morning with dew points reaching around 18-19°C. Temperatures will climb towards a high of 29°C which will feel closer to the mid-30’s with the humidity factored in. For the afternoon, attention will turn towards the potential for severe thunderstorms as a cold front pushes southeastwards into the Red River Valley.

These thunderstorms may be severe with the primary threats being large hail and localized flooding due to intense downpours. Strong wind gusts are possible with these storms as well. At this point, it seems like a tornado threat is unlikely, but we’ll keep an eye on things as they develop.

After the cold front slides through, winds will shift out of the northwest at around 15-25 km/h and the humidity will begin to ease as drier air moves into the region. Temperature will still remain warm, though, with overnight lows dropping only to around the 17°C mark once again.

Wednesday will be another hot day with temperatures climbing to around the 28°C mark with partly cloudy skies in the morning. The humidity will be much more comfortable than on Tuesday thanks to drier air that works in through the day and drops dew points back down to the low teens for the afternoon. Expect a low near 17 or 18°C on Wednesday night with a slight chance of another shower or thunderstorm as a weak disturbance slides through the region.

Long Range.

Looking further ahead, temperatures will cool towards seasonal to round out the work week as slightly cooler air moves in behind Wednesday night’s disturbance.

The heat begins building back in through the weekend, and next week is looking quite warm and relatively humid as an upper ridge builds over the western Prairies, spreading above-normal temperatures across the region.

Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 13°C.