On 6-7 August 2012, heavy rains brought by the southwest monsoon (Habagat) and enhanced by Tropical Storm Haikui dumped 323mm of rainfall in Central and south Luzon over a period of 24 hours.

As a result, flood waters swept the National Capital Region (NCR) as well as Regions II and IV-A. On 8 August 2012, the southwest monsoon continued to bring widespread rains and devastation in Northern and Central Luzon.

A total of 56 cities and municipalities in the NCR and Regions II and IV-A have been affected by flooding. 41 of these cities and municipalities were placed under a State of Calamity.

The National Disaster Risk Reduction and Management Center (NDRRMC) reported that the number of families affected is now 864,424 or an estimated 3,883,218 persons. 106 persons died. The cost of damage to infrastructure is PHP639,128,230.00 while the damage to agriculture was estimated at PHP1,626,033,175.14.

Typhoon Helen (International Code Name "Kai-Tak"), which dumped more rains into Northern Luzon and Metro Manila, moved out of the Philippine Area of Responsibility on 16 August 2012. However, the storm left seven people dead, according to the NDRRMC.

To date, authorities have recorded a total of PHP24,953.984.36 in monetary donations and at least PHP162,525,584.45 in kind assistance from foreign donors, the Filipino community and various entities abroad, including the Government of Canada through CIDA and Sun Life Financial.

According to the NDRRMC, "all emergency response actions (search and rescue, relief and recovery operations) in connection with the flooding as a result of the southwest monsoon rains have already been terminated and everything is back to normal."