Ontario’s Morning Hot Spot Cools Down Fast in Thunder Bay

Thunder Bay, ON – Friday, March 21, 2025 – Thunder Bay is waking up as Ontario’s morning hot spot — and in late March, a balmy 2.8°C actually qualifies as “hot.” Observed at 7:00 AM EDT from Thunder Bay Airport, skies are cloudy, winds are blowing in from the west-southwest at 19 km/h, and humidity is a moderate 56%.

Visibility is a clear 24 km, though a look at the falling barometric pressure (99.6 kPa) hints at changes ahead.

While this warm start may feel like a spring sneak peek, don’t put away the parka just yet. There’s a 40% chance of rain showers or flurries this morning, followed by a few flurries beginning late this morning.

Winds will shift northwest and increase to 20 km/h, gusting up to 40, and the temperature is expected to tumble to -2°C by late afternoon. With the wind chill, it’ll feel more like -10°C. UV index? Just a low 1, so it’s a great day to forget your sunglasses without consequence.

Winter’s Return Tonight – Cold, Clear, and Crisp

Tonight, any lingering flurries should wrap up early in the evening, giving way to clearing skies. However, the clearing comes with a serious cooldown. Winds from the northwest at 20 km/h (gusting to 40) will die down late in the evening, but not before helping drop temperatures to a biting -18°C.

The wind chill tonight will make it feel like -22°C — ideal weather for staying indoors with a blanket and an aggressively oversized mug of hot chocolate.

Weekend Weather – A Bright Start, But Snow’s Not Far Behind

Saturday, March 22nd brings plenty of sunshine, but don’t let the clear skies fool you. The morning starts off with a brutal wind chill near -25°C. The temperature will climb to a high of just -5°C, with wind chills still near -10°C in the afternoon.

Winds will shift again, becoming southeast at 20 km/h by late day. UV index rises slightly to 3 — moderate — so the sun may be weak, but it’s not shy.

Saturday night brings increasing cloud cover and a 60% chance of snow, with a low of -11°C. Sunday continues the wintry streak with periods of snow and a high of -2°C. Expect more snow Sunday night with a low of -7°C.

Monday finally offers a hint of moderation with cloudy skies and a high right around 0°C — positively tropical compared to the weekend. Monday night remains cloudy with a low of -8°C.

What to Wear – Spring at 7 AM, Deep Winter by Dinner

This is the kind of day where you start in a light jacket and end the day bundled like an Arctic explorer. Dress in layers — base warmth, a windproof mid-layer, and a solid winter jacket to top it off. Gloves and a hat are a must this afternoon and evening when the wind kicks in and temperatures plunge. Boots are a good idea too, especially with those afternoon flurries.

Weather Trivia: Thunder Bay’s March Madness

On this date, March 21st, Thunder Bay once reached a record high of 14.4°C in 1938 — practically beach weather by northern standards. The record low? A bone-numbing -31.7°C set back in 1965. So today’s brief flirtation with warmth is a luxury, even if it vanishes faster than a snowman in July.