Record warmth in Ontario and Quebec plus tropical storm Bonnie

After the record warmth, strong thunderstorms moved across northwest Vermont on Sunday. (WCAX TV)

It is Memorial Day south of the border on this Monday, typically the "official/unofficial" start of summer. The weekend featured weather extremes across eastern and central North America, with searing heat, severe thunderstorms and tornadoes, and even a tropical storm for good measure. Record warmth surged into the Great Lakes and Quebec with dozens of new record highs established. Notables included Montreal, 31.7C (89F) on Friday, surpassing the record of 30.4C (86F) from 1978. Montreal managed 28C (83F) both Saturday and Sunday, with a slight northeast breeze keeping us a little cooler. On Sunday, Ottawa reached 33.2C (91F), breaking the old record of 31.4C from 1978. It was so hot in Burlington, Vermont on Sunday, organizers were forced to call off the Vermont City Marathon after runners were already on the course, four hours into the event. It was the first cancellation in the marathon's 28 year history. Several participants were treated for heat-related issues. However, many refused to stop and completed the event.

In the late afternoon, strong thunderstorms developed over eastern New York and impacted the northern Champlain Valley as far north as extreme southern Quebec. Wind damage and flooding was reported in St. Albans, Vermont. Only a few rumbles of thunder and less than 2mm of rain occurred in Montreal. We are very dry, with only a paltry 32mm of rain for the month of May in and around Montreal.

Tropical storm Bonnie produced heavy rain across coastal South Carolina on Sunday.

Also this weekend, tropical storm Bonnie developed off the Florida coast and moved northwest into South Carolina. The storm produced widespread heavy rain and flooding in coastal North and South Carolina. Bonnie has since been downgraded to a depression and is located 60 miles southwest of Myrtle Beach Monday morning. Maximum winds were around 30mph. The biggest threat from Bonnie this week will be rough surf, and up to 3 inches (75mm) of additional rainfall from North Carolina into the middle Atlantic sates.