The Cyril Quakes comprise, at minimum, a pair of strong shocks—one with a northern epicenter and another with a southern epicenter. The southern event appears to have struck first (see Ghor-es-Safi for details). The first shock occurred around 10:30 pm on Sunday 18 May 363 CE; the second followed at about 4:30 am on Monday 19 May 363 CE. Ambraseys (2009) and Kagan et al. (2011) argue for two events because a single source seems unlikely to account for the breadth and severity of reported effects. The letter attributed to Cyril of Jerusalem also distinguishes two shocks, with the earlier causing the greater damage in Jerusalem. Damage reports extend from southern to northern Palestine and from the Mediterranean coast to Petra, with Libanius mentioning damage in Syria.

Although some narrative elements may reflect theological agendas or appeals for rebuilding funds, archaeoseismic evidence supports widespread destruction. The primary textual witnesses include Christian authors writing after a period of intense conflict. In 363 CE, Julian the Apostate was Roman emperor; after he renounced Christianity as the state religion, he allowed or encouraged the rebuilding of the Jerusalem Temple (destroyed in 70 CE). Work had reportedly just begun when the 18–19 May 363 CE earthquakes disrupted those efforts. Then, Julian died in late July 363 CE. Christian writers often framed these events as signs of divine intent—both displeasure with Julian and with attempts to rebuild the Temple which the Christian authors thought was accursed. Reporting surrounding the earthquakes contain embellishments such as crosses appearing in the sky and on the clothes of "Jews", mysterious fires, and invisible forces keeping those working on the Temple project from leaving their homes (Cain and Lenski, 2009). Guidoboni et. al. (1994), citing Brock (1977:267), notes that such details suggest oral transmission. It can also be suggested that these written accounts were aggrandized to support the controlling narrative of the triumph of Christianity. Ambraseys (2009) suggests that some of the writers may have conflated effects of the Crete Earthquake of 365 AD with the Cyril Quakes.

Jerusalem appears to have have suffered a destructive fire after the main shock(s). The letter attributed to Cyril — likely derived from an early contemporaneous report — states that many died in a fire and heavy rains following the earthquake. In that letter, an apparently supernatural fire is said to have issued from a synagogue and killed many people (Jews) fleeing toward it after the earthquake. Gregory of Nazianzusa, who wrote about these events within a year of the earthquake, describes a flame within a church (perhaps the Holy Sepulchre) directed toward the workers/Jews. Some later writing authors reported that the flame/fire came out of the sky or the Temple foundations itself. These variants plausibly reflect the embellishment of an urban conflagration into a miracle narrative.

Several catalogs also mention a seiche in the southern Dead Sea, apparently following Jerome. Jerome’s passage is somewhat ambiguous — it appears to conflate regional tsunamis from the AD 365 Crete earthquake with the effects of the Cyril Quakes but it is possible Jerome preserved an oral tradition from Areopolis of a seiche in the Dead Sea after the 363 CE Cyril Quakes. The textual record nevertheless lists numerous towns “overthrown” by the earthquakes as well as an extended sequence of aftershocks following the main shocks.