Climate in Pennsylvania
(United States)

Average daytime and nighttime temperatures

All climatic diagrams on this site result from the collected data from eleven measuring weather stations in Pennsylvania.
All data correspond to the average monthly values of the last 20 years.
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Pennsylvania is one of the coldest regions in the United States of America with an average daily high temperature of only 16 degrees. The climate is very changeable and offers varied seasons with deep winters and warm summers.
Overview: Climate in the United States of America
Daylengths and sun positions in the United States of America
Compare climate with other regions or countries
Hours of sunshine per daySunshine hours per day in Pennsylvania
The number of hours of sunshine refers to the time when the sun is actually visible. That is, without any obstruction of visibility by clouds, fog or mountains. With 9 hours per day, July is the sunniest month in the state of Pennsylvania. In December the sun shines the shortest.
Rainy days per monthRainy days per month in Pennsylvania
A rainy day is a day on which at least an amount of 0.1 mm precipitation (=0.1 liter) per square meter falls. This can be rain, snow, hail or even dew. So it does not have to rain the whole day. With 11 rainy days, December offers the most number of rainy days, and in September the least.
Precipitation in mm/dayPrecipitation in Pennsylvania
The amount of precipitation is measured in millimeters per square meter. Thus, at two mm/day, two liters of water fall on one square meter within 24 hours. With only 2.4 mm, the least rain falls in January. July, on the other hand, has the most rain.
Relative humidity in %Relative humidity in Pennsylvania
Warm air can absorb more moisture than cold air. The relative humidity indicates how much moisture of the physically possible is actually contained in the air. At high humidity, the person feels uncomfortable and perceives this as oppressive. In general, a relative humidity of 40-60% gives as pleasant. With humidity averaging 72%, September is the most uncomfortable. In April, on the other hand, it is easier to endure.
Absolute humidity in g/m³Absolute humidity in Pennsylvania
In warm months, there is also a higher absolute humidity almost everywhere. At a temperature of 25°C, air can absorb up to 23 grams of water per cubic meter. At 20°C, it is only 17.3 grams. A relative humidity of 40% at 25°C thus corresponds to an absolute humidity of 9.2 grams of water. From a proportion of approx. 13.5 grams, humans perceive the air as muggy. This limit is only reached in a few months in Pennsylvania, although these are always average values.
Humidex in °CHumidex in Pennsylvania
The "Humidex" (humidity index) is an index of well-being in warmer areas, calculated from the air temperature, relative humidity and dew point. The index corresponds approximately to the temperature felt. At high temperatures, the body transports heat away by sweating. At high humidity the ambient air can only absorb a small amount of sweat and thus one feels uncomfortable. An index of 20-29 is considered comfortable. Up to 39, people perceive the air as slightly uncomfortable, and above 40, as very uncomfortable. Values above 45 are dangerous in the long run and often lead to heat stroke.
Map of Pennsylvania

Most important cities in the federal state »Pennsylvania«

The federal state has a west-east extension of about 480 km and over 270 km from north to south.

CityPopulationGeo position
Philadelphia1,576,59639° 57' 8"N75° 9' 50"W
Pittsburgh301,04840° 26' 26"N79° 59' 45"W
Allentown120,44340° 36' 30"N75° 29' 25"W
Erie101,04742° 7' 45"N80° 5' 6"W
Reading88,08240° 20' 8"N75° 55' 37"W
Scranton76,08941° 24' 33"N75° 39' 54"W
Bethlehem74,98240° 37' 33"N75° 22' 14"W
Lancaster59,32240° 2' 16"N76° 18' 20"W
Levittown52,98340° 9' 18"N74° 49' 44"W
Harrisburg49,52840° 16' 25"N76° 53' 4"W
Altoona46,32040° 31' 7"N78° 23' 41"W
York43,71839° 57' 45"N76° 43' 40"W
State College42,03440° 47' 36"N77° 51' 36"W
Wilkes-Barre41,49841° 14' 45"N75° 52' 53"W
Norristown34,32440° 7' 17"N75° 20' 24"W
Chester33,97239° 50' 59"N75° 21' 25"W
Mount Lebanon32,73040° 21' 19"N80° 2' 58"W
Bethel Park32,31340° 19' 39"N80° 2' 22"W
Wayne30,89240° 2' 38"N75° 23' 16"W
Radnor30,87840° 2' 46"N75° 21' 36"W
Williamsport29,38141° 14' 28"N77° 0' 4"W
Monroeville28,38640° 25' 16"N79° 47' 17"W
Cranberry Township28,09840° 41' 6"N80° 6' 26"W
Drexel Hill28,04339° 56' 49"N75° 17' 32"W
Plum27,12640° 30' 1"N79° 44' 58"W
Back Mountain26,97341° 20' 9"N75° 59' 47"W
Easton26,80040° 41' 18"N75° 13' 15"W
Lebanon25,47740° 20' 27"N76° 24' 41"W
Hazleton25,34040° 57' 30"N75° 58' 29"W
Whitehall Township24,89640° 40' 0"N75° 29' 60"W

Data basis: German Weather Service, individual values averaged and supplemented by own elements. Data on cities and inhabitants:, United Nations Statistics Division and own research.
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