These dates conventionally delimit the period of each year when most tropical cyclones form in the southern Pacific Ocean east of 160°E.

Ahead of the cyclone season, RSMC Nadi, TCWC Wellington, the Australian Bureau of Meteorology (BoM), the New Zealand National Institute of Water and Atmospheric Research (NIWA) and various other Pacific Meteorological services, all contributed towards the Island Climate Update tropical cyclone outlook that was released during October 2009.

[5] In addition to contributing towards the Island Climate Update outlooks, RSMC Nadi issued their own seasonal forecast for their area of responsibility.

[3] Within their outlook RSMC Nadi predicted that between eight and eleven tropical cyclones, would occur within the basin compared to an average of around 9.

[4] As a result, it was predicted that the island nations located to the west of the International Date Line, would face a near average risk of being affected by a tropical cyclone.

[4] However island nations to the east of the dateline such as Niue and Tonga, faced an increased risk of being affected by a tropical cyclone.

[6] The El Niño event slowly decayed due to consistently negative SOI values and weak trade winds in the tropics.

Late on December 3, RSMC Nadi reported that Tropical Disturbance 01F had developed out of a weak area of low pressure to the northeast of Fiji.

Over the next few days the disturbance gradually developed before RSMC Nadi reported that it had intensified into a tropical depression late on December 11.

As a result of land interaction, Tropical Cyclone Mick rapidly weakened and became an extratropical depression early the next day.

[7] Early on January 7, RSMC Nadi reported that an extratropical depression had formed about 770 km (480 mi), to the southwest of Papeete in French Polynesia and assigned it the designation of 03F.

By the 10th it reached Severe Tropical Cyclone strength as it moved towards the southern Cook Islands, and a hurricane warning was then issued for Aitutaki and its neighbours.

[16] On February 17, RSMC Nadi commenced reporting on an unnumbered tropical disturbance located near 8.6ºS 162.0ºW, about 120 miles (190 km) north-northwest of Rakahanga in the Cook Islands.

[19] Located within an environment characterized by low wind shear, further intensification was anticipated as convection continued to develop over the expanding system.

Rapid intensification was expected to take place over the following 48 hours as sea surface temperatures ahead of the storm averaged 30 °C (86 °F), well-above the threshold for tropical cyclone development.

[24] Convective banding substantially increased on March 13, allowing Tomas to become the fourth severe tropical cyclone of the season early the next morning.

[24] Tomas intensified on the night of March 14 and became a Category 4 severe tropical cyclone(according to the Fiji Meteorological Service) with winds up to 170 km/h and gusts up to 215 km/h blowing roofs off some houses and damaging buildings around the eastern side of Vanua Levu.

[27] One person was killed on Vanua Levu after being swept out to sea by large swells while trying to rescue her two sisters, a niece and a nephew near Namilamila Bay.

[28] During March 30, RSMC Nadi reported that a depression had developed, along a trough of low pressure about 450 km (280 mi) to the southeast of Port Vila, Vanuatu.

[31] The following weak tropical disturbances and depressions were also monitored by RSMC Nadi, however these systems were either short lived or did not develop significantly.

During December 6, Tropical Disturbance 02F developed within a trough of low pressure about 1000 km (620 mi), to the north of Suva, Fiji.