Just How Hot Can It Be in July?

Temperatures don't often reach 100 degrees in the Mid-Atlantic Region

July typically features some of the hottest weather of the year across much of the country, including in the Mid-Atlantic Region.  Although it hasn’t been 100 degrees in the Nation’s Capital since 2012, July has seen some extreme and record setting heat during the last five years.

To read more, click on this link to see the story I wrote for the WUSA9 website.

Weather Quiz

"Looking" to keep cool !

What is the hottest temperature ever recorded in Washington, D.C. (in degrees Fahrenheit)?

       A.    102

       B.     105

       C.     106

       D.    107

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Answer to Weather Quiz question from June 25.

B.  2005.   

Hurricane Wilma made landfall in southwest Florida on October 24, 2005 as a Category 3 hurricane.  Although damaging hurricanes have made landfall in the United States since Wilma such as Ike in 2008 and Irene in 2011, they weren’t “major.”  That helps illustrate the fact that a hurricane doesn’t have to be a Category 3 or higher to be destructive or deadly.

Cooler and Wetter than Average?

Nationals Park, Washington, D.C.  (June 2015)

What meteorologists and weather enthusiasts alike find so fascinating about the weather is its ability to change dramatically – sometimes over a relatively short period of time.  Such has been the case in the Mid-Atlantic Region during the last two months.  Following the warmest and one of the driest May's on record in the Nation’s Capital, June was the second wettest and sixth warmest. 

 

June’s wet weather has continued into the first week of July across the DC Metro Region.  However, temperatures have remained cooler than average during the last several days.  Although May saw seven days of at least 90 degrees in Washington, D.C., and June saw 12 such days, there hasn’t been any 90 degree heat so far in July.  The warmest temperature Washingtonians have experienced this month was on July 1 when it was 88 degrees at National Airport (the average high for the date).  It hasn’t been 90 degrees in the Nation’s Capital since June 23.

During the 12 day-period from June 23 through July 4, more than 6” of rain was measured in Washington, D.C.  That’s approaching the combined average of 7.51” that falls in the Nation’s Capital during all of June and July.  In fact, the 0.85” of rain that fell yesterday made for the wettest Independence Day in Washington, D.C. since 2004.  Fortunately, the fireworks on the National Mall got off without any weather delays last night.  A persistent front has helped keep the Mid-Atlantic Region wetter than average with below average temperatures during the last several days. 

 

That’s completely unlike early July 2012 when there was an 11 day stretch in the Nation’s Capital with high temperatures of at least 95 degrees.  In fact, it was 100 degrees on July 5, 2012, and that began a stretch of four consecutive days that were at least 100 degrees in Washington, D.C.

Scientists at NOAA’s Climate Prediction Center aren’t expecting this July to be exceptionally hot in the Nation’s Capital.  In fact, their seasonal outlook for this July is for an equal chance of above or below normal temperatures in the Mid-Atlantic Region with a slight chance for the month being wetter than average.  Since July has already seen 2.2” of rain downtown and the month averages a total of 3.73”, it’s more than likely that the month will see above average precipitation.  My colleagues and I on the WUSA9 Weather Team will continue to provide people with the latest weather forecasts.

Early Season Hurricanes

"Arthur" approaching North Carolina on July 3, 2014  (Source: NASA)

Although a tropical storm forms on average every other June in the Atlantic Ocean, a hurricane so early in the season is much more unusual.  A hurricane develops in June on average only once every five years according to data from NOAA. 

So far in 2015, there have been two named storms.  Tropical Storm Ana formed before the season began (on June 1) and made landfall in South Carolina on May 10.  Tropical Storm Bill developed on June 15 and made landfall in Texas on June 16.  However, there hasn’t been a hurricane during the month of June in the Atlantic Ocean Basin (that also includes the Gulf of Mexico and Caribbean Sea) since 2012.  That’s when Chris became a minimal hurricane and brought Bermuda some appreciable rainfall.  Ironically, 2012 was the last busier than average hurricane season in the Atlantic Ocean.

There was also a rare June hurricane in 2010, when Alex became a Category 2 storm with sustained winds of 110 mph in the western Gulf of Mexico.  It made landfall in northeastern Mexico with some of its effects being felt across southern Texas.  A system gets a name when sustained winds reach tropical storm strength around the center of 39 mph.

Once maximum sustained winds reach 74 mph (as they did in Alex on June 29, 2010) the system becomes a hurricane. Conditions were ideal for Alex to intensify with exceptionally warm ocean water – well above the 80 degree threshold.  The pressure in Hurricane Alex dropped to a relatively low level of 946 millibars – more characteristic of a borderline Category 3/Category 4 storm on the Saffir-Simpson Hurricane Scale.  Alex was the first June hurricane to form anywhere in the Atlantic Ocean Basin since 1995.

Sometimes the first hurricanes don’t form until much later in the season.  In 1992, the first named storm of the season also became the season’s first hurricane.  Andrew formed in mid-August and remains one of the costliest natural disasters on record and only the third Category 5 hurricane to make landfall in the United States.  More recently, in August 2011, Hurricane Irene became the first hurricane of the season on August 22.

It was at this point last season that meteorologists at the National Hurricane Center and holiday beachgoers were tracking Hurricane Arthur.  It was the first named storm of the 2014 season and developed into a hurricane on July 3.  Arthur became a Category 2 hurricane with sustained winds of 100 mph and gave eastern North Carolina a glancing blow.  Unlike last July, no tropical storms or hurricanes are expected anywhere in the tropical Atlantic Ocean this July 4^th holiday weekend.