Wednesday, June 28, 2017

Typical Summer Weather Means Different Things Depending Where You Live

Linda Lam
Published: June 28,2017

"Typical summer weather" is a phrase frequently used this time of year. However, its meaning varies depending on the region of the U.S.
By the summer months, the jet stream usually has shifted farther north toward the Canadian border resulting in more active weather in portions of the northern tier of the U.S. This shift also allows warmer temperatures to spread north, along with an increase in moisture in some areas.
(MAPS: Average Monthly Temperatures)
Below we take a closer look at what typical summer weather means for each region.

Warm and Wet in the Northeast

Summer in the Northeast brings pleasantly mild to warm temperatures.

By July, average high temperatures are in the lower 80s for much of New England and Upstate New York, with 70s in far northern New England and close to the eastern Great Lakes. Farther south from New York City into the mid-Atlantic, average highs in July climb into the mid-to-upper 80s.
Average highs begin to cool slightly moving through August, but remain warm.
Temperatures cool down nicely overnight. Much of the region experiences lows in the 60s in July and August, with 50s in portions of Upstate New York and northern New England.
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There are periods of hot and humid weather, sometimes for several days resulting in a heat wave. These hot and humid periods typically come to an end when a cold front moves through with strong to severe thunderstorms.
In fact, due to the active weather and increase moisture, July is the wettest month of the year in New York City, with 4.6 inches of rainfall on average, and in Burlington, Vermon,t and Syracuse, New York, with 4.16 inches and 3.78 inches, respectively.

Hot and Humid Across the South

When most think of the South during the summer, hot and humid conditions are what come to mind.
Areas typically are hot and humid through the Southeast into the Deep South and toward the Gulf Coast through the summer months. Dew points in the 60s and 70s are common, making it feel hotter than the thermometer indicates.

Average Highs in July

Average highs in the low-to-mid 90s in July stretch from parts of the Carolinas into Florida westward into Houston and northward into Dallas. Areas from northern Alabama and northern Georgia northward usually see highs in the upper 80s. The average high in Atlanta in July is 89.1 degrees and 88.1 degrees in August.
Lows in the 70s are common during the summer, although some areas farther north, including Raleigh, experience lows in the upper 60s.
The higher elevations of the Appalachians, of course, see cooler conditions with highs in the low-to-mid 80s and lows in the low-to-mid 60s.
(MORE: Why Pop-Up Summer Thunderstorms Are Among the Hardest Weather to Predict)
Scattered afternoon thunderstorms are also common across the region, given its proximity to the Gulf of Mexico, which provides ample moisture. Depending on the weather pattern, these pop-up thunderstorms can be a regular occurrence.
The regular thunderstorms during the summer months, which can have locally heavy downpours, quickly add to the rainfall totals.
June is the wettest month of the year in both New Orleans (8.06 inches on average) and Houston (5.93 inches on average). July is the wettest month in Atlanta, with 5.27 inches falling, and in Raleigh, where an average of 4.73 inches accumulates.

Warm, Stormy Midwest

Warm temperatures, with periods of hot and humid conditions, are common in much of the Midwest and Plains in the summer. The Midwest is similar to the Northeast in that cold fronts move through bringing relief from the heat and humidity.

Average highs are in the 80s in July and August for much of the region, except from northern Minnesota into parts of Wisconsin and Michigan where highs in the 70s are common. The cooler water temperatures of the Great Lakes help to bring a break from the heat in areas close to the coast.
Lows usually dip into the 60s, with 50s from portions of the Dakotas through the northern Great Lakes.
Although average temperatures are quite manageable, temperatures can soar into the 90s and even 100s at times. In addition, dew points can rise into 60s and 70s, reaching uncomfortable levels.
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The northern storm track combined with an increase in moisture surging northward can result in an active pattern with thunderstorms with heavy rainfall.
In Fargo, North Dakota, June is the wettest month of the year with 3.90 inches falling on average. August is the wettest month in Chicago, with an average rainfall of 4.90 inches. Summer is also the wettest season in Minneapolis.

Northwest and Interior West Stays Dry and Warm

Areas from the Pacific Northwest into the Rockies typically experience warm temperatures and drier conditions in summer.

Average Highs in August

Average highs are pleasant in Seattle, where temperatures usually top out in the mid 70s in July and August. Portland, Oregon, typically sees highs in the lower 80s. Lows in both cities are comfortable and average in the mid 50s. However, heat waves do occur occasionally.
In parts of the interior West, highs climb into the lower 90s in Salt Lake City and Boise, Idaho, and lows are in the lower-to-mid 60s. Farther north, Missoula, Montana, experiences average highs in the mid 80s in July and August, with lows near 50 degrees.
(MORE: What Your Car Thermometer Is Wrong)
The warm temperatures are typically accompanied by plenty of sunshine and fairly low dew points, especially compared to the East. July and August are the driest months Seattle, Portland, Boise and Salt Lake City.
Conversely, July is the wettest month in Denver, which is far enough south and east that monsoon moisture and developing upper-level disturbances can bring thunderstorms to the area during the summer months.

Sizzling in Parts of Southwest and California

Hot conditions and dry conditions prevail in the Southwest in summer.

Although rainfall totals are meager compared to other areas of the U.S., July and August are actually the wettest months in Phoenix and Albuquerque. As the Southwest monsoon begins to kick in, typically in July, there is an increase in precipitation. The monsoon is caused by the intense heating in the region which results in a wind shift that brings moisture northward into the Southwest.
The formation of thunderstorms can also result in strong winds that can pick up dust and sand, creating dust storms.
In addition to the risk of thunderstorms, scorching temperatures are typical in Phoenix and Las Vegas where highs average in the lower 100s and lows usually only fall into the 80s.
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In California, summer is the driest season. San Francisco, for example, on average does not see any rainfall in July and only 0.06 inches in August, a stark contrast to the December-Februar average of 4.5 inches each month.
Along the coast, average highs are mild to warm, given the influence of the cool Pacific Ocean. However, central California can be quite hot. San Francisco experiences average highs in the mid-to-upper 60s, and average temperatures top out in the lower 90s in Sacramento.
MORE: Heat Wave Plagues the Southwest, June 2017 (PHOTOS)

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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