On January 13, TCWC Nadi started to monitor a shallow depression that had developed within the monsoon trough about to the west of Espiritu Santo, Vanuatu. Over the next day the system moved eastwards and developed further as gale-force winds developed near the systems centre before the JTWC initiated advisories on the system and designated it as Tropical Cyclone 11P during January 14. The system was subsequently named Eric by TCWC Nadi as it moved closer to Espiritu Santo and became equivalent to a category 1 tropical cyclone. During January 15, Eric passed near or over Espiritu Santo, as it continued to intensify before it turned and accelerated south-eastwards. Eric subsequently became equivalent to a category 3 severe tropical cyclone early the next day, before an Air Pacific flight from Fiji to the Solomon Islands located the systems eye on radar. During January 17, Eric's well defined eye came into the range of Nadi airports surveillance radar, before TCWC Nadi estimated that Eric had peaked with 10-minute sustained wind-speeds of 150 km/h. During that day Eric's eye seemed to contract to around as it made passed through Fiji's Western Division and made landfall on the Fijian main island of Viti Levu about to the south of Nadi. After the system had made landfall, the JTWC estimated that Eric had peaked with 1-minute sustained wind speeds of 185 km/h, which made it equivalent to a category 3 hurricane on the SSHWS. The system subsequently passed near or over Fiji's capital: Suva before emerging into the Korro Sea and weakening. Eric subsequently passed through the Tonga's Ha'apai islands just to the south of Nomuka during January 18, before it gradually weakened and was last noted during January 20, over to the south of Papeete, French Polynesia.
Severe Tropical Cyclone Nigel
Late on January 16, Tropical Cyclone Nigel moved into the South Pacific basin from the Australian region. During the next day the system continued to move eastwards and developed an eye, before it became equivalent to a modern-day category 3 severe tropical cyclone.
Severe Tropical Cyclone Odette
At around 1300 UTC on January 19, Severe Tropical Cyclone Odette moved into the South Pacific Basin from the Australian Region.
Severe Tropical Cyclone Freda
During January 26, the FMS reported that a depression was located within the vicinity of the Southern Cook Islands about to the west-northwest of the island of Aitutaki.
Tropical Cyclone Gavin
Gavin caused widespread flooding within the western division of Fiji, with seven people killed as a result.
Severe Tropical Cyclone Hina
Hina was one of the most intense tropical cyclones ever recorded in the South Pacific basin. A 2017 reanalysis found that Hina's maximum one-minute sustained wind speeds were much higher than originally thought, estimating a peak intensity of 170 kt.
Season effects
This table lists all the storms that developed in the South Pacific basin during the 1984–85 season. It includes their intensity on the Australian Tropical cyclone intensity scale, duration, name, areas affected, deaths, and damages. For most storms the data is taken from RSMC Nadi's and or TCWC Wellington's archives, however data for 03P has been taken from the JTWC/NPMOC archives as opposed to RSMC Nadi's or TCWC Wellington's, and thus the winds are over 1-minute as opposed to 10-minutes.