If you planning to travel to St. Lawrence Power Development, Cornwall, Ontario, Canada, here is your 6-day travel weather forecast to make sure you have all the essentials needed during your stay. Start your day when the sunrises at 12:32 PM. The temperature feels like 31.7 with a humidity level of 85 so dress accordingly. Cloud coverage is 72 percent with visibility at 9.3 percent. Today’s UV index is 1, don’t forget the sunscreen if you need it! Today’s winds are traveling southwest at a speed of 14 MPH. At the end of the day don’t miss the sunset at 9:20 PM.