A ridge of hot and humid air has built up from the U.S. into much of eastern Canada. The summer sizzle is expected to peak mid-week with relief by the start of the weekend. Heat warnings persist for the Annapolis Valley, N.S., with Environment Canada cautioning of daytime highs reaching 29 to 33 C and feeling into the high 30s with the humidex. It is possible further heat warnings will be issued for other parts of the Maritimes this week as temperatures climb and humidity remains high. The criteria for a heat warning vary slightly between each Maritime province but generally consist of two or more days of very hot and humid weather with warm nights that don’t offer much relief. The hot and humid air can serve as fuel for thunderstorms. A severe thunderstorm watch was issued for the northwestern corner of New Brunswick just before noon on Monday. The period of greatest risk of thunderstorms for the area will extend from 3 p.m. to 8 p.m. The situation with thunderstorms can change quickly, including the watches and warnings associated with them. Be weather aware and seek shelter indoors should a thunderstorm develop in your vicinity. Peak of the heat Heat warnings were issued for much of the Maritimes late Monday afternoon. The warnings are expected to extend into Thursday and call for daytime highs of 28 to 33 C (33 to 39 C with humidex) and nighttime lows of 16 to 20 C. Parts of the coastlines will be slightly more moderate including the Bay of Fundy coastline of New Brunswick and directly on the Atlantic coastline of Nova Scotia. Those coastal areas with highs closer to the mid 20s. Wednesday is set to be hottest day for the region. Widespread high temperatures of 28 to 33 C. The humidex will make it feel into the mid-to-high 30s and for some communities close to 40 C. Thursday high temperatures only come down by a degree or two in most cases. Temperatures on Friday come down a few more degrees but it will still be very warm and muggy. There is a higher chance of both showers and thunderstorms on Friday as a weak weather front approaches from the west. The weather agency recommends the public check on people who could be more vulnerable to heat during the hottest times this week. They advise monitoring for signs of heat exhaustion including headache, nausea, dizziness, thirst, dark urine and intense fatigue. Heat exhaustion can be treated by resting in a cool area and drinking water. Heat stroke is more severe. Signs include red, hot skin, confusion, and loss of consciousness. In the event of heat stroke, emergency personnel should be contacted. Humidity breaks The humidity in the Maritimes is expected to break for the weekend. Dew point temperatures, a measure of moisture in the air, are expected to be in the high teens and low 20s much of this week. That is a level many find uncomfortable when combined with the summer heat. A weak cold front passing through Friday is expected to draw in some less humid air from the north into the region. Dew point temperatures falling towards the low-to-mid teens for Saturday. Temperatures are still expected to be plenty warm on the weekend. Daytime highs on both Saturday and Sunday are likely to be in the mid-to-high 20s. There is the possibility for a more widespread rainfall for the Maritimes next Monday.
