Crisp Morning Air Gives Way to Haze, Heat, and a Fiery Forecast for Monday
Thunder Bay, ON – It’s a classic Northwestern Ontario flip: after starting the day near freezing, Thunder Bay is heading for a sun-soaked high of 26°C, with hazy skies and wildfire smoke drifting in overnight. Get ready for a dramatic shift as the region warms rapidly — but also prepares for showers and potential thunderstorms early in the workweek.
Sunday: From Fridge to Furnace
As of 6:00 AM EDT, Thunder Bay Airport is reporting a mainly sunny sky and a brisk 2.1°C. With light winds at 4 km/h from the west, humidity is a moist 93%, and visibility stretches a full 32 km. Barometric pressure is on the rise at 101.4 kPa.
Today will be sunny and hazy, with the high soaring to 26°C. The UV index is 8 – very high, so sunscreen, sunglasses, and wide-brimmed hats are must-haves if you’re outdoors. Hydrate often — especially if you’re headed to parks, trails, or backyards for weekend fun.
Tonight: Clear Skies and Incoming Smoke
Tonight remains clear and calm, but haze will thicken into local smoke overnight as wildfire smoke begins to drift in from the west and north. The overnight low will sit around 10°C — mild, but less refreshing than the crisp morning start.
Monday: Summer Heat and Storm Potential
On Monday, June 2, the mercury keeps climbing, with a high of 27°C and a humidex of 32 — making it feel like July. The morning starts sunny, but skies will turn into a mix of sun and cloud by midday with a 30% chance of showers and risk of thunderstorms in the afternoon.
Southwest winds will gust up to 50 km/h, helping push smoke into the area, contributing to local air quality concerns. The UV index jumps to 9 — so once again, sun safety is key.
Monday Night and Tuesday: Rain Lingers
Monday night remains unsettled with cloudy skies and a 60% chance of showers, dipping to a low of 13°C.
Tuesday continues cloudy with another 60% chance of showers, keeping the high to a more seasonable 19°C. Relief arrives Tuesday night with clearing skies and a low of 7°C.
Wednesday: Sunny and Settled
Wednesday, June 4, brings a return to stability with sunny skies and a high of 23°C, perfect for catching up on outdoor plans without dodging heat or downpours. The night remains clear and comfortable with a low of 7°C.
Wardrobe & Health Tips
Today: Start layered, but switch to shorts and tees by mid-morning.
Monday: Sunblock, water bottles, and storm awareness will all be essential.
Smoke-sensitive residents should monitor symptoms and stay indoors if smoke becomes concentrated — especially by Monday afternoon and evening.
Weather Trivia: Did You Know?
Thunder Bay’s June temperature record stands at a sizzling 34.4°C, set in 1988 — a year that also featured forest fire smoke drifting in as early as May. While we’re not quite there yet, this week’s forecast is a strong early-season reminder of how quickly summer arrives on Superior’s doorstep.
