Summer, generally the most pleasant time of year, has warm days and cool nights. About 60% of possible sunshine is received during summer. The average daily maximum temperatures are generally in the low eighties, while nighttime daily minimum temperatures average in the high fifties. Maximum temperatures of 90íF or greater occur about 15 to 20 days a year during June, July, and August. The maximum recorded temperature at Scranton, 103íF, occurred on July 9, 1936. The annual precipitation for the area is approximately 37 inches. Late spring and summer receive the most yearly precipitation. An average of seven thunderstorms occurs during each of the summer months. Heavy rainfall associated with hurricanes or tropical storms moving up the east coast are occasional and result in flooding of the lower areas. The average noon relative humidity for the area during the summer is about 55%.

Winter is cold and cloudy with daytime maximum temperatures in the mid-thirties and nighttime daily minimum temperatures in the high teens to low twenties. The record low temperature, -21íF, occurred on January 21, 1994. Winter precipitation is light but frequent and is received as rain or snow. The annual snowfall for the area is about 40 inches, but varies widely from the lower to higher elevations. The average total number of days with snow cover of an inch or more is 50. The average noon relative humidity for the area during the winter is about 60%.

Alternate periods of freezing and thawing occur frequently in spring and fall. Sunshine becomes more prevalent during spring with temperatures rising, while autumn sunshine provides many mild days and cool nights through much of October. The average dates for the last freeze in spring and the first in fall are April 24 and October 14, respectively.

• the largest vein of anthracite coal in the world is under the Lackawanna Valley. Most of the coal is still there.
• the original name of Scranton was Slocum Hollow
• the first commercially operated locomotive in the U.S., the Stourbridge Lion, made its inaugural run between Honesdale and Carbondale.
• the Archbald Pothole is the largest glacial pothole in the world.
• Elmhurst is one of two townships totally within another township in Pennsylvania.
• the first commercially successful electric street car system was put into service in Scranton in 1866.
• an "Irish War" between rival factions of Irish rail workers was fought near Clarks Summit in 1850.
• Jefferson Township contains the highest elevation in the county. (2323 ft.)
• the Susquehanna River in Ransom Township is the lowest elevation in the county. (540 ft.)
• Dalton was first known as Bailey Hollow.
• LaPlume Township was the birthplace of baseball great Christy Mathewson.
• Roaring Brook Township borders nine Lackawanna County communities, giving it more neighbors than any other municipality.
• Vandling Borough separated from Fell Township in 1899, after dissatisfaction and lack of representation in township affairs.
• Waverly gave up its borough charter in 1920 and is now a part of Abington Township.
• the first blast furnace was built in Old Forge.
• the first underground coal mine was opened in Carbondale.
• Taylor was where the first white settlers located in Lackawanna County.
• Jermyn was first called "Baconville."
• the first iron "T" rails were built at the Lackawanna Furnace in Scranton.
• the Scranton Lace Company was the first producer of Nottingham Lace in the United States.
• Scranton was once called the "Anthracite Capital of the World."
• the first county census was taken in 1880, showing a population of 89,269.
• Archbald was originally called "White Oak Run."
• Mayfield was originally called "Glendale."
• when Throop became a borough on April 16, 1894, it had a population of 8.
• Jessup has had several name changes. It was originally known as "Saymour," then became "Mount Vernon," and then "Winton," before being named after the prominent Jessup family of Montrose.
• Dunmore was first called "Bucktown."
• there was once a municipality called Lackawanna Township. However, Old Forge, Moosic, Taylor, and the twenty-second and -sixth wards of Scranton were created out of it.
• during World War I, Minooka (now a part of Scranton) sent the largest number of volunteers to service of any community its size in the country.
• the first institution of higher education in northeastern Pennsylvania, the Madison Academy, was established in Waverly in 1844.
• Springbrook Township is the largest municipality in terms of land in the County.

Most bedrock underlying the Appalachian Plateaus province consists chiefly of red to brownish shale and sandstone of the Catskill Formation, which is upper Devonian in age.

The Appalachian Mountain section of the Valley and Ridge province is known as the Lackawanna Valley and is a long synclinal trough with the outer rim made up of a very hard resistant sandstone and conglomerate of the Pocono Formation. The inner rim is made up of bedrock of the Pottsville Formation. Between the two rims is a thin section of soft Mauch Chunk shale. The inner synclinal trough contains folded and faulted beds of post-Pottsville shale, sandstone, and some conglomerate and several mineable anthracite coal layers. Several minor anticlines and synclines are in the Plateaus province in the remaining part of the county.

During the Pleistocene Epoch, a series of great continental ice sheets advanced and retreated, covering Lackawanna County with accumulations of glacial debris of sand, rounded gravels, and boulders from melt water. Other material that was deposited directly from the ice with little or no sorting or stratification is distributed unevenly throughout the region and is classified as glacial till. This till is as much as 300 feet deep in some places, and the present topography is the result of erosion of this glacial drift.

Another suburban population concentration exists beyond West Mountain around the area of U.S. Routes 6 & 11, Interstate 81, and the North­eastern Extension of the Pennsylvania Turnpike Interchange. This area includes the boroughs of Clarks Green, Clarks Summit, Dalton, and the townships of Abington, Glenburn, and South Abington.

Smaller settlement clusters associated with rural-agricultural areas include: Montdale, Justus, Fleetville, LaPlume, Milwaukee, Tompkinsville, Finch Hill and Ransom to the west of the valley area; and Elmhurst, Moscow, Daleville, Mount Cobb, Madisonville, Springbrook, and Thornhurst to the east of the valley.

Also, settlement clusters containing a mix of summer and year-long residences are located at Chapman Lake, Newton Lake, Crystal Lake, Lake Sheridan, Baylors Lake, Handsome Pond, Deer Lake, Bassett Pond, and Lake Kewanee to the west of the valley; and at Moosic Lakes, Lake Spangenburg, Lake Kahagon, Eagle Lake, Big Bass Lake, and Bear Lake to the east of the valley.

The remaining areas of the county are rural, with scattered farms and virgin forestland. There are approximately 315 active livestock and crop farms in Lackawanna County today.

Topographically the features that stand out the most in Lackawanna County are the two nearly parallel mountain ranges that traverse the county in a southwest to northeast direction, forming the valley area. The range of mountains forming the east boundary of the valley is known as Moosic Mountain, while the opposite range is known as West Mountain.

The two mountain ranges naturally trisect the county. Each of these ranges reaches an average height of 2,000 feet above sea level, while the valley floor ranges in elevation from 600 feet in the southwestern section to 1,500 feet in the northeast. Beyond West Mountain in the northwest section of the county, ele­vations are generally 800 to 2,000 feet. Beyond Moosic Moun­tain in the southeast section of the county, elevations range from 1,100 to 2,300 feet.

The Lack­awanna River flows through the valley between the two mountains. It accounts for the drainage of approximately two-thirds of Lackawanna County. The westerly slopes of West Mountain drain to tributaries of the Susquehanna River, and the easterly slopes of Moosic Mountain are drained by the Lack­awanna and Lehigh Rivers and their tributaries.

The slopes of both mountain ranges are generally 20 percent or greater; whereas, the rest of the county is fairly uniform. The section beyond West Mountain is mostly in the 5 to 20 percent range, and the lands be­yond Moosic Mountain are in the 1 to 10 percent range.