Weather Service in the military history of the Philippines started in the early 1917 when the organization of the Signal Corps Aviation Section under the Philippine National Guard had been given due importance and gained more recognitions in military aviation which evolved from its humble beginning to its present status as one of the major service of the AFP, the Philippine Air Force.
There was however, no established weather unit during those early years of the Philippine Air Force. Weather service was then the sole responsibility of each Major Command. Major Air Bases like Nichols Air Base, (now Col Jesus Villamor Air Base), Basa Air Base and Fernando Air Base maintained their own weather personnel which were then assigned with each respective Base Operations.
It was only in 1961, when the Headquarters Philippine Air Force realized the importance of centralizing the weather service and organization for the PAF in particular and for the AFP in general. This centralization led to the activation and organization of the 901st Weather Squadron.
The 901st Weather Squadron was activated A weather the Unit of the AFP and assigned to the Philippine Air Force effective 29 December 1961. It was entrusted with a mission “To provide specialized meteorological services, including meteorological observations, forecasts and climatological studies to support the AFP and other government agencies”. It was, however organized and manned only on 15 May 1962, pursuant to section I, GO Nr 113; HPAF dated 08 May 1962, with an authorized personnel strength of 18 Officers and 122 Airmen. Due to the lack of qualified personnel however, the original actual manning was only 8 Officers and 40 Airmen who were drawn from different bases of the PAF.
The first Headquarters of 901st WS was located in the old MIA building, then known as Balabag Area. The set-up of the unit then was as follows; A unit Headquarters, a Forecast Center at the Base Operations, three (3) Weather Detachments; Weather Detachment 1 in Basa Air Base, Pampanga, Weather Detachment 2 in Fernando Air Base, Lipa City and Weather Detachment 3in Mactan Air Base, LapuLapu City.
Later on, with increasing demand for the weather services due to the operations of AFP as well as its involvement in the socio-economic program and development of the government, more weather detachments and Sites was established. Weather Detachment 4 in Edwin Andrews Air Base, Zamboanga City, Weather Detachment 5 in Sangley Point, Cavite City and a weather Sites in Gozar Station, Lubang Island, Mindoro Occidental were established. At present, there are twenty three (23) Detachments and Elements located all over the Philippines.
In 1976, the 902nd Weather Reconnaissance Squadron (Provisional) was dissolved and subsequently absorbed by 901st Weather Squadron. The 902nd WRS mission was to conduct artificial rain stimulation/rain suppression, typhoon moderation, seed dispersal and other related meteorological activities. The absorption of 902nd WRS expanded the mission of the 901st WS from a ground unit to a flying unit. It has one (1) C-47 and three (3) Cessna 210 aircraft that were used purposely in its weather modification activities.
In 1980, the 901st WS was re designated and reorganized as Air Force Weather Service (Provisional) to meet more increasing demand on weather services of the whole AFP as well as other civilian entities.
On 01 November 1987, the unit sustained a blackmark in its history. The AFWS was unmanned as a Unit of the PAF for reasons that it was not cleared until now. The morale of the personnel was at its lowest due to the effect on the unmanning of the unit. As the saying goes “after the passage of typhoon, the sun is sure to shine again” that on 01 February 1989, the AFWS was manned and renamed as Air Force Weather Group (AFWG).
The manning of the unit again was short lived. After one (1) year and four (4) months of re-emergence, the AFWG was unmanned again on 01 June 1990, after the changing of the guards at Higher Headquarters. This succession of events demoralized the personnel and some even vowed not to be assigned in the weather unit again. However after the more than one (1) year of inactivity, the unit was manned again and renamed 900th Weather Service Group on 16 October 1991. On 01 June 1995, the unit was again renamed 900th Air Force Weather Group.