September is a popular month to ask about Thunder Cove because conditions can shift week to week along this coast. Expect the water near 17.0°C, with daily variation from wind, tides and recent storms. We refresh the live value from Open-Meteo Marine every hour, so the headline above always reflects the current state of the Gulf of St Lawrence.
Thunder Cove sea temperature in September — averages 17.0°C
The sea at Thunder Cove in Canada averages 17.0°C during September, based on long-run climatology for the Gulf of St Lawrence. Use the live reading below for today's actual water and the monthly grid to compare with the rest of the year.
Average sea · September
17.0°C
mild · Fair
Live water now
…
Recommended wetsuit
3/2mm fullsuit
At 17.0°C a 3/2mm fullsuit is the standard wetsuit for surfing and watersports.
Monthly comparison
Yes, but expect a fresh dip · Thunder Cove
Can you swim at Thunder Cove in June? — 13.0°C water13.0°CCan you swim at Thunder Cove in July? — 18.0°C water18.0°CCan you swim at Thunder Cove in August? — 20.0°C water20.0°CCan you swim at Thunder Cove in September? — 17.0°C water17.0°CCan you swim at Thunder Cove in October? — 12.0°C water12.0°CCan you swim at Thunder Cove in November? — 6.0°C water6.0°C
Frequently asked questions
What is the average sea temperature at Thunder Cove in September?
Thunder Cove averages 17.0°C in September, based on long-run climatology for the Gulf of St Lawrence.
Is the sea warm enough to swim at Thunder Cove in September?
It is swimmable but fresh; confident swimmers will be fine without a wetsuit.
Do I need a wetsuit at Thunder Cove in September?
A 2 mm shorty is comfortable for sessions over 30 minutes.