Thunder Bay’s three-day forecast calls for highs of 25°C to 27°C, very high UV levels, scattered showers and a thunderstorm risk
Thunder Bay is starting Tuesday with mainly sunny skies, light winds and very high humidity. Temperatures will climb into the mid-20s this afternoon before unsettled conditions return late in the day.
The three-day forecast calls for progressively warmer weather through Thursday, with daytime highs reaching 27°C on Wednesday and Thursday. Scattered showers are possible each day, along with a risk of thunderstorms Wednesday afternoon.
No weather warning or advisory was included in the Environment Canada forecast information available for this update.
Today’s Weather Overview
Current Conditions
At 8:00 a.m. EDT on Tuesday, July 28, Thunder Bay was mainly sunny with a temperature of 13.1°C.
Humidity was 99 per cent, with a dew point of 12.9°C. The high humidity and nearly matching temperature and dew point indicate that the morning air is holding a significant amount of moisture.
Winds were from the west-southwest at 7 km/h, while visibility was 32 kilometres.
Barometric pressure was 101.4 kPa and rising, supporting the generally fair weather expected through the morning and early afternoon.
Three-Day Thunder Bay Forecast
Tuesday, July 28
Thunder Bay will remain sunny through the morning and early afternoon.
A mix of sun and cloud will develop later in the day, bringing a 30 per cent chance of showers late this afternoon.
The high will reach 25°C, with a Humidex value of 30.
The UV index will be 8, or very high. Sun protection will be important, particularly during the middle and late parts of the day.
Tonight will be partly cloudy with a 30 per cent chance of showers early in the evening. Skies will clear overnight.
The low will fall to 13°C.
Wednesday, July 29
Wednesday will begin sunny and remain bright through the morning and early afternoon.
Cloud cover will increase later in the day, with a 40 per cent chance of showers developing during the late afternoon. There will also be a risk of a thunderstorm.
The high will reach 27°C, with a Humidex of 31.
The UV index will again be 8, or very high.
Wednesday night will bring cloudy periods and a 30 per cent chance of showers.
The overnight low will be 15°C.
Thursday, July 30
Thursday will bring a mix of sun and cloud with a 40 per cent chance of showers.
The high will reach 27°C.
Cloudy periods will continue Thursday night, with a 30 per cent chance of showers.
The overnight low will be 17°C, making for a noticeably warmer night than Tuesday.
Wardrobe Recommendations
A light sweater or jacket may be useful during the cool Tuesday morning, but warmer and more humid conditions will develop quickly.
Lightweight and breathable clothing will be the most comfortable choice during the afternoons. Sunglasses, sunscreen and a hat are recommended because the UV index will be very high today and Wednesday.
Keep a light rain jacket or umbrella nearby, especially late Tuesday afternoon and again Wednesday afternoon when showers may develop.
Anyone planning outdoor activities Wednesday should monitor the sky and updated forecasts because thunderstorms may form later in the day.
Weather Trivia
Barometric pressure can provide clues about changing weather. Rising pressure often suggests improving or stable conditions, while falling pressure may indicate that cloud, precipitation or a weather system is approaching.
Thunder Bay’s pressure was rising Tuesday morning, matching the sunny conditions expected through the first part of the day.
