DAR ES SALAAM, Sept. 9 -- THE rain did not stop. It fell through the day, drummed through the night and turned ordinary roads into rivers that swallowed bridges, cut railway lines and cut off communities from food and essential services.

In Musoma, Standard Six pupil Fredrick Pundo watched classmates disappear from school as flooded paths became too dangerous to cross.

In Shinyanga, farmer Dotto Tumbo saw her familys rice harvest triple before cassava rotted in soaked fields because there was nowhere dry enough to save it.

Nearly three decades later, those memories still define what many Tanzanians mean when they talk about El Niño.

The 1997/98 episode remains the benchmark disaster against which meteorologists, climate researche...