World Weather/Climate Extremes Website

World: Greatest One-Minute Rainfall

Record Value 31.2mm (1.23")
Date of Record 4/7/1956
Length of Record 1948-present
Instrumentation Recording Rain Gauge "in satisfactory exposure"
Geospatial Location Unionville, MD [38°48'N, 76°08'W, elevation: 152.18m (499ft)]


Krause and Flood, 1997: Weather and Climate Extremes, US Army Corps of Engineers Topographic Engineering Center pp. 89;


Krause and Flood (1997) note that the total precipitation during the storm was 91.0 mm (3.6 inches) of which 72 mm (2.84 in) fell during a 50-minute period from 2:50 to 3:40 P.M.

Unionville, MD, USA

Closeup Satellite Image of Modern Unionville, MD, USA

Unionville, MD, USA

Regional Satellite Image of Modern Unionville, MD, USA