Low pressure in US midwest brings unseasonable heat to New York and Boston

Further south this week, severe thunderstorms affected midterms voting in Florida, Oklahoma and Colorado Despite the rapid descent into autumn in the northern hemisphere, parts of eastern North America have experienced an exceptionally late taste of summer in recent days. Temperatures approached 23C (73F) in New York and Boston, about 7-10C above what is expected in early November.

The unseasonable warmth spilled into parts of eastern Canada, with temperatures exceeding 20C, about 10-15C above normal for the time of year. The balmy conditions were caused by an area of low pressure in the US midwest, dragging up exceptionally warm air from the Gulf of Mexico along its eastern flank.

This area of low pressure will gradually drift eastwards, allowing temperatures to fall closer to the average. Further south, severe thunderstorms have resulted in numerous flood warnings and evacuation warnings being issued this week across many states, with disruptive weather affecting polling stations in Florida, Oklahoma and Colorado.