Historical weather data, all-time temperature records, and monthly climate averages for Lebanon, NH. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Lebanon runs cold, with an average high of just 48° and a low of 29° across 54 years of records. The date has seen wild swings though — from a balmy 74° in 2010 to a brutal 2° in 2016. There's a 43% chance of precipitation today, with a small but real 7% shot at snow.
Lebanon's weather has real teeth: the thermometer has swung from a bone-cracking -30° in January 1968 all the way to 100° as recently as June 2025. A single storm dropped 25.6 inches of snow on February 7, 1978, and a September storm in 1999 dumped 4.7 inches of rain in one day. This is a place where the extremes are not abstract.
Lebanon is warmest in mid-July, when highs average 83°, and coldest in mid-January, when highs barely crack 28°. Late June through early July is the wettest stretch of the year, averaging over an inch of precipitation per week. If you're planning a visit, late summer offers the warmest and drier conditions before autumn's chill arrives quickly in October.