Thunder Bay Weather: Warm Midweek Conditions Before Cooler, Showery Saturday
THUNDER BAY — Weather Desk – Thunder Bay is heading into a generally comfortable stretch of mid-August weather from Wednesday, Aug. 12 through Saturday, Aug. 15, with daytime highs near 25 C through Thursday before cooler air arrives for the weekend.
Wednesday starts mostly cloudy, but conditions should remain relatively warm. Thursday carries a chance of a shower before Friday emerges as the best outdoor-weather day of the four-day period. A more noticeable change arrives Saturday, when temperatures fall to around 19 C and showers return.
Thunder Bay Forecast for Aug. 12-15
Wednesday, Aug. 12
Thunder Bay begins Wednesday under mostly cloudy skies, with a temperature around 14 C during the morning.
The daytime high is expected to reach 25 C.
Wednesday night will remain relatively mild for mid-August, with an overnight low near 13 C.
For people working outdoors, heading to camp or spending time along the waterfront, Wednesday should offer generally workable conditions despite the cloud cover.
Thursday, Aug. 13
Thursday brings a mixture of sunshine and cloud along with the possibility of a shower.
The high will again reach about 25 C, while the overnight temperature falls to 13 C.
Anyone planning a day on Lake Superior or one of the inland lakes should keep an eye on changing skies. Even a brief shower can bring localized changes in wind and visibility.
Friday, Aug. 14
Friday currently looks like the strongest outdoor day of the forecast period.
Mostly sunny skies are expected, with a daytime high near 23 C.
Friday night will cool to around 13 C.
The combination of sunshine and temperatures in the low 20s should make Friday favourable for construction, yard work, hiking, camping and other outdoor activities.
Saturday, Aug. 15
A weather change moves into Thunder Bay Saturday.
Skies will become mostly cloudy, with a couple of showers possible through the day. Temperatures will also be noticeably cooler, reaching only about 19 C.
The overnight low will remain around 13 C.
People planning Saturday outdoor events, camping trips or time at the lake should have rain gear available and check the updated forecast before leaving.
Lake Superior and Highway Travel Outlook
The most favourable travel and outdoor recreation period currently appears to run from Wednesday through Friday, particularly Friday when mostly sunny conditions are forecast.
Motorists travelling Highway 11/17 east or west of Thunder Bay should be prepared for potentially wetter conditions Saturday. Showers can produce localized reductions in visibility, particularly on stretches of highway around the Nor’Wester Mountains, Nipigon and exposed areas near Lake Superior.
Boaters should continue checking marine forecasts separately before heading onto Lake Superior. Conditions on the big lake can differ substantially from those reported at Thunder Bay Airport.
Four-Day Weather at a Glance
Wednesday: Mostly cloudy. High 25 C. Low 13 C.
Thursday: Partly sunny with a shower possible. High 25 C. Low 13 C.
Friday: Mostly sunny. High 23 C. Low 13 C.
Saturday: Mostly cloudy with a couple of showers. Cooler. High 19 C. Low 13 C.
The main weather story is the temperature shift heading into Saturday: after two days around 25 C, Thunder Bay is expected to lose about six degrees from Thursday’s daytime high as cloud and showers move in.
