Hurricanes and Tornadoes That Hit Jonestown, PA

The nearest NOAA station with 1991–2020 climate normals is Lebanon 2 W, PA, 7 miles south of Jonestown at 450 feet. July is the warmest, with an average high of 84°F and low of 64°F; January is the coolest, at 37°F and 22°F. July is the wettest at 4.9 inches of precipitation on average and February the driest at 2.6 inches; the year adds up to 46.5 inches over 81 days with at least a tenth of an inch. June to November, the hurricane season months, bring 56% of the year's precipitation (25.9 of 46.5 inches); the other six months are drier. August has brought the most of the 23 tropical systems that passed within 75 miles (8); a normal August there has highs of 82°F and 4.6 inches of precipitation. Highs reach 90°F on about 13 days a year, almost all from June to August. Lows fall below freezing on about 120 nights a year. Snowfall averages 24.0 inches a year, most of it in February. That 46.5 inches is more than at 95 of the 148 Pennsylvania stations used on this site (64%). Grantville, 7 miles west, has its own station (Dehart Dam, PA): 50.9 inches a year, 4.4 more than here, and the same July average high, 84°F.

Since 1996, the National Weather Service has logged 214 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Jonestown: 176 thunderstorm wind reports, 27 flash floods, 10 floods and 1 heavy rain event. They killed 1 person and injured 0, and the NWS estimated $781,000 in property and crop damage. The strongest thunderstorm gust on record here was 115 mph, on June 27, 2002. June has had the most flash floods, 11 of 27. Of the 788 Pennsylvania cities on this site with a flash flood on record, 401 have had fewer than Jonestown.

Flood insurance policyholders in Jonestown's ZIP code 17038 have filed 104 claims with the National Flood Insurance Program since 1978, and were paid $3.1 million for buildings and contents, in the dollars of each year. The most came from Tropical Storm Lee in 2011: 28 claims (27% of all) and $1.8 million, then Tropical Storm Ivan in 2004 with 10. 56% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 553 Pennsylvania cities on this site with 10 or more claims, 385 have fewer than Jonestown.