High Heat and Humidity

Lake Champlain looked inviting yesterday near Plattsburgh Beach in upstate New York. The Green Mountains are in the background. It will be 90 - 95F in Plattsburgh today.
ValleyWX Pic

High heat and humidity advisories are in effect across a wide area of southern Quebec today and into the middle portion of this week. High pressure over the eastern portion of the continent is surging a tropical air mass of hot and humid air up the entire eastern seaboard. This morning the mercury is already at 24C in downtown Montreal and 26C at both Toronto and NYC. The temperature will climb to 33C today with humidex reading in the low 40's. Across the east coast highs will be close to the 100F mark in New York and Washington and mid 90's in Boston. The heat will be accompanied by smog and poor air quality. Advisories are in place across all of western and northern New York as well as southern and eastern Ontario and southern Quebec. Overnight lows will only cool slightly to the mid 20's. There is no break in site at least until the end of the week. Scattered thunderstorms will prevail most afternoons and evenings. According to the NWS in Burlington, this week has the possibility of being a true heatwave, the first since 2003. A heatwave is 90F (32C) or higher on three consecutive days or more.

Keep in mind in this type of heat and smog, heat exhaustion is possible. It is important to stay hydrated and cool. Watch for the signs of heat exhaustion and get into the shade of air conditioning if needed. Pay special attention to the afternoon period when the effects of sun, heat and humidity are at their greatest.

From Environment Canada
Metro Montréal - Laval 4:42 AM EDT Monday 05 July 2010
High heat and humidity warning for Metro Montréal - Laval continued

A hot and very humid airmass will cover these regions today making conditions very uncomfortable. During this period, people suffering from chronic diseases (E.G. Heart and respiratory diseases) could see their conditions deteriorate. Exposure to these conditions could also cause discomfort, such as muscle cramps, exhaustion and heatstroke. In order to better withstand the heat, it is recommended that people drink a lot of water, limit physical activities and seek out air conditioned or shady areas. If you are concerned for your health or need more information, call 811 to contact info-health services in your area.