Very early in the history of IMD, the importance of the publication of scientific results had been recognised. Blanford introduced the publication of the "Memoirs of the IMD" and himself authored several of them. His work on the rainfall of India is unsurpassable in clarity of thought and content. In view of the importance of foreshadowing monsoon seasonal rainfall for the agricultural economy of the country, Blanford initiated the system of Long Range Forecasting (LRF). The system of LRF of monsoon rains went through several evolutionary phases and eminent pioneers like Sir J. Eliot and Sir Gilbert Walker (Both Directors-General of Observatories) and generations of Indian researchers have made their contributions to this scientific effort.

To Sir Gilbert Walker also goes the credit of linking the monsoon with global meteorological situations and his discovery of the so-called Southern Oscillation phenomenon. Swings of the Southern Oscillation were later linked by J. Bjerknes with the EI Nino in the equatorial Pacific Ocean and Bjerknes also coined the term "Walker circulation" for describing the east west vertical circulation in the equatorial plane in honour of Walker. 

 
Blanford had recognized the need for inducting young Indians in IMD and the first two Indians Lala Ruchi Ram Sahni (Father of Professor Birbal Sahni) and Lala Hemraj joined IMD in 1884 and 1886 respectively. The Indianisation of IMD was accelerated under Walker, soon after World War I, and further boosted by Sir C.W.B. Normand (Director-General during 1928 to 1944). Normand was succeeded by Dr. S.K. Banerji as the first Indian DGO in 1944. During these years, many Indian scientists joined IMD and they took IMD to greater heights themselves in the post-independence era.