Excessive Heat — Lancaster, Pennsylvania

2025-07-25 · Lancaster, Pennsylvania

Event narrative

Well-above average temperatures, coupled with humid conditions, allowed for heat index values to exceed 105 degrees during the afternoon and evening hours of July 25, 2025 across Lancaster County. Lancaster Airport reported multiple hours of heat index values between 105 and 107 degrees, topping out near 110 degrees. Multiple cooling centers were opened throughout the county on July 25th.

Wider weather episode

Residence time in the warm sector ahead of a surface cold front allowed for portions of central Pennsylvania to experience ample heating in a highly moist environment during the afternoon hours of July 25, 2025. A combination of heat and humidity allowed for portions of the Lower Susquehanna Valley to experience multiple hours with heat index values exceeding 100 degrees. Lancaster Airport topped out with a heat index of 110 degrees during the mid-afternoon hours.

Source: NOAA Storm Events Database, event_id 1276652. Narrative written by the NWS forecast office that issued the report.