And The Heat Goes On...

As of noon today, Boston's temperature reached 90 degrees for the 16th day this year! Of all of those days, there have really only been a handful when it has been truly intolerable due to the oppressive humidity. The last three 90-degree days met the criteria for heat advisory and even an excessive heat warning! Become familiar with these heat safety tips.

• Heat Wave - Prolonged period of excessive heat, often combined with excessive humidity.
• Heat Index - A number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees.
• Heat Cramps - Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.
• Heat Exhaustion - Typically occurs when people exercise heavily or work in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim's condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.
• Heat Stroke - A life-threatening condition. The victim's temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly.
• Sun Stroke - Another term for heat stroke.
• Excessive Heat Watch - Conditions are favorable for an excessive heat event to meet or exceed local Excessive Heat Warning criteria in the next 24 to 72 hours.
• Excessive Heat Warning - Heat Index values are forecast to meet or exceed locally defined warning criteria for at least 2 days (daytime highs=105-110° Fahrenheit).
• Heat Advisory - Heat Index values are forecast to meet locally defined advisory criteria for 1 to 2 days (daytime highs=100-105° Fahrenheit).

During the winter, I predicted that this summer was going to be a scorcher and the hottest certainly since 2010 when there were 25 days over 90 in Boston. My initial expectation of 20-25 days over 90 still stands. In late spring, I narrowed that range down to about 22 days over 90 for the city. Statistics reveal that most but not all summers in years that were transitioning out of a moderate to strong El Nino contained well above the average of 90-degree days. A couple of those analog years were 2010 and 1983. My oldest son was born in the late winter of 1983 and I will never forget how brutally hot that summer was. In fact, September 1983 contained four record high temperatures namely 94 on the 6th, 99 on the 11th, 92 on the 19th and 97 on the 20th! Whew! Can we conclude that will be repeated this September? Not necessarily. There are other factors that must be considered but based upon global conditions especially the location of positive and negative sea surface temperature anomalies, I believe that we are vulnerable to a few days at 90 or higher. As a result, I think that the number will be quite close to the anticipated 22 days.

The hot zone of New England is poised over mainly north central MA into interior southern NH. Some of the locales in this area of northwestern Essex County, northern Middlesex County into northern Worcester County of MA and western Rockingham County and Hillsborough County in NH have already recorded 20-29 days at 90 or higher! Some of those places may have at least a couple more days over 90 this week while coastal communities like Boston will be subjected to a bit cooler weather due to an onshore breeze.

Overall, the summer has been awesome with fantastic weather in June when there were many nice warm days accompanied by ultra low humidity. July contained 12 days over 90 but many of them without horrendous humidity. For those who have been disappointed and complaining about the lack of hot weather in the past few summers, I think you should happy with this summer. Are you ready for fall or would you like more hot weather? Just curious.

The WBZ AccuWeather Team will continue to monitor the drought and keep an eye on the sky for severe weather and watch the tropics as the peak of the hurricane season approaches.

Stay cool!