Bethlehem Pennsylvania Climate Data

Monthly Average Climate Data for Bethlehem Pennsylvania

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January21.3 °F38.2 °F3.53 in.
February22.6 °F41.0 °F2.74 in.
March29.8 °F49.7 °F3.74 in.
April40.0 °F62.1 °F3.69 in.
May50.0 °F72.1 °F4.1 in.
June59.3 °F80.7 °F4.7 in.
July64.1 °F85.2 °F4.74 in.
August62.3 °F83.3 °F4.5 in.
September54.9 °F76.7 °F4.65 in.
October43.4 °F64.8 °F3.9 in.
November33.7 °F53.6 °F3.27 in.
December26.7 °F43.1 °F4.18 in.
Annual42.3 °F62.5 °F47.74 in.

Climate Data for Bethlehem Pennsylvania

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 11 - May 20
Average Days With Frost100-125 Days
Plant Hardiness Zone - 2023Zone 7a : 0°F to 5°F
Plant Hardiness Zone - 2012Zone 6b : -5°F to 0°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation