The writer sketches geographical distribution of the rainfall in Panama, and follows with an account, with tables and figures, of monthly and hourly precipitation, local showers, and excessive rainfall. Whatever rain occurs on the Isthmus must be attributed to local convection currents in conjunction currents with the deflective effects of hills and mountains on such winds as there are.

The rainfall on the north side exceeds that on the south side of the Isthmus, and is greatest on the north coast and locally on the higher portions of the Caribbean slope. The mean annual rainfall at Colon is 129.04 inches; at Porto Bello 169.15 inches, and at Balboa 91.61 inches.

An excessive downpour in a brief period, probably 2.48 inches in 5 minutes at Porto Bello, May 1, 1910, seems to have been the most intense rainfall ever recorded.