Historical weather data, all-time temperature records, and monthly climate averages for Lebanon, PA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Lebanon lands right in the heart of spring's wide swing — over 62 years of records, highs on this date have ranged from 22° to 80°, so pack layers. Today's average sits at a mild 57° high and 37° low, with roughly a coin-flip chance (44%) of seeing some rain.
Lebanon's weather has real teeth on both ends: the thermometer has hit 103° on a Fourth of July and plunged to -22° in January, a span of 125 degrees. A single June storm once dumped 8.85 inches of rain, and a January blizzard in 2016 buried the area under 24 inches of snow.
Lebanon's warmest stretch runs mid-July, when average highs peak around 85–86°, while mid-January is the depths of winter at a frigid 36°. Late July is also the wettest stretch of the year, averaging 1.25 inches in a week, so summer visitors should expect afternoon storms. Spring and fall offer the most comfortable conditions, with highs climbing from 50° in March to 65° by October.