The Ninth Plague, three days of complete darkness.

God causes three days of complete darkness.

 

Resources used:

Carl Friedrich Keil and Franz Delitzsch, Commentary on the Old Testament, vol. 1 (Peabody, MA: Hendrickson, 1996), 323.

 

Douglas K. Stuart, Exodus, vol. 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 255–261.

 

https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/clouds/mid-level-clouds/nimbostratus