Delhi recorded more than half of the rainfall in September in just 24 hours ending 8:30 am on Friday, swinging from being rain deficient to rain surplus this month.

The Safdarjung Observatory, Delhi's primary weather station, recorded 58.5 mm of precipitation against a normal of 108.5 mm between September 1 and September 22 (Thursday morning).

It received 72 mm of rainfall in 24 hours ending 8:30 am on Friday, making it the first spell of heavy rain this month. From September 1 to September 23, the city received 130.5 mm of rain. Normally, Delhi records 125.5 mm of rainfall in September.

The weather stations at Palam, Lodhi Road, Ridge Ayanagar and Pusa received 102 mm, 71.4 mm, 41.4 mm, 106.2 mm and 51 mm of rainfall between 8:30 am on Thursday and 8:30 am on Friday.

Rainfall recorded below 15 mm is considered light, between 15 and 64.5 mm moderate, between 64.5 mm and 115.5 mm heavy, between 115.6 and 204.4 very heavy. Anything above 204.4 mm is considered extremely heavy rainfall.

The weather bureau has attributed the heavy rain to the interaction of a Western Disturbance and a low-pressure system.

The capital has recorded only two spells of heavy rain this monsoon season -- the first being on July 1 when the city gauged 117.2 mm of rainfall.

The incessant rains in the last two days have also brought down the overall deficit in the monsoon season.

Delhi's overall rain deficit in the monsoon season dropped from 35 per cent (till September 22) to 23 per cent by Friday morning.

More rains are expected before the monsoon retreats from the National Capital Region by the end of September which may further reduce the deficit.