The hydrometeorology of the Amazon basin in the ERA-40 reanalysis for 1958–2001 is compared with observations of precipitation, temperature, and streamflow. After 1979, the reanalysis over the Amazon has a small cool bias of the order of 0.35 K, and a small low bias of precipitation of the order of 0.3 mm day . In the early years (1958–72), there is a large upward drift in reanalysis precipitat...