Seasonal start to October with rising warmth, humidex values near 28°C, and storm chances building by Thursday

Thunder Bay greets the first day of October with cloudy skies, mild temperatures, and high humidity — signs that a warming trend is underway. After today’s cooler high near 19°C, temperatures climb into the mid-20s Thursday through Saturday, with thunderstorm risks returning by tomorrow afternoon. This is shaping up to be a rare early October warm spell, fueled by southern air and moisture moving in from the Prairies.

Current Conditions

• Observed at: Thunder Bay Airport

• Time: 6:00 AM EDT

• Temperature: 13.1°C

• Dew Point: 11.3°C

• Humidity: 89%

• Wind: ENE at 9 km/h

• Visibility: 24 km

• Pressure: 102.5 kPa (falling)

• Condition: Cloudy

Today’s Weather Overview

Wednesday, October 1:

• A mix of sun and cloud as skies gradually brighten through the day.

• Winds remain light and easterly.

• High: 19°C

• UV Index: 5 (moderate)

Tonight:

• A few clouds, calm and quiet conditions.

• Low: 12°C

Extended Forecast

Thursday, October 2:

• A mix of sun and cloud.

• 30% chance of showers in the afternoon, with a risk of a thunderstorm.

• Winds becoming south at 20 km/h late in the morning.

• High: 25°C, humidex: 28°C

• UV Index: 4 (moderate)

• Night: Cloudy periods, 30% chance of showers.
  Low: 11°C

Friday, October 3:

• A mix of sun and cloud with a 30% chance of showers.

• High: 23°C

• Night: Cloudy periods, 40% chance of showers.
  Low: 12°C

Saturday, October 4:

• A mix of sun and cloud, with a 40% chance of showers.

• High: 26°C

• Night: Cloudy, with a 30% chance of showers.
  Low: 11°C

Wardrobe Recommendations

• Today:

  • A light jacket or long-sleeve layer is ideal with highs near 19°C.

• Thursday–Saturday:

  • Short sleeves or breathable fabrics as humidex values rise toward 28°C.

  • Keep a light rain jacket or umbrella handy due to scattered storm chances.

  • Mornings and evenings remain mild — a light sweater should suffice.

Weather Trivia

Did you know?
Thunder Bay’s record high for October 2 is 25.6°C, set in 1992. With Thursday’s forecast of 25°C and humidex of 28°C, the city may flirt with that record. While average highs this time of year are around 13°C, this week’s heatwave is being driven by a southerly wind flow tapping into warm Prairie air and increasing atmospheric instability — a classic setup for October thunderstorms.

Enjoy the fall warmth — and prepare for storm chances Thursday through Saturday. Stay connected to the NetNewsLedger Weather Desk for the latest updates.