Australia’s northern wet season build up is underway, with parts of the Kimberly already receiving over half their average October rainfall, according to Weatherzone.

October represents the transition between the region's dry and wet seasons. Kununurra's average monthly rainfall jumps from 3mm during September to 62mm in November. Over the border, Darwin goes from just 16mm to 140mm.

WeatherZone explains that increasingly warm waters off northern Australia increases the amount of moisture available in the atmosphere, while rising temperatures over the land trigger convection. This recipe leads to more frequent and more intense showers and thunderstorms.

Showers and storms on the first day of October have signalled the start of this year's wet season build-up. During the 24 hours to 9am this morning, Mount House Airstrip recorded 36mm of rain. Mount Elizabeth received 22mm, which is 70 percent of the usual October rainfall.

Thunderstorms also visited the Darwin area on Sunday morning, bringing the city’s first rain since May.

The storms arrived just in time for the rain to be included in September, preventing Darwin from recording its first dry September for 11 years. The wettest part of the year in Darwin usually occurs from December to March.

Meanwhile the longest dry-spell on record in Alice Springs was broken, but only just, last Thursday when three millimetres of rain was recorded in the Centralian capital.

Prior to that fall, Alice Springs had not received a single drop of rain for 157 days, with the last fall registered back in April. 

Weatherzone senior forecaster Ashley Patterson said the previous record without rain in Alice Springs 147 days in 1972.

Further South, Brisbane registered its driest Sepember in 12 years.