At Hacienda Barú we began measuring and recording the daily rainfall in 1981. Our first rain gauge was a tin can, and we measured the water level with a short ruler. Ten years later the Costa Rican Institute of Meteorology installed an official weather station here with a sophisticated rain gauge and thermometers for measuring high and low temperatures. In 2014 they installed an electronic weather station that sends the data to them at their national headquarters by internet. All of the data in the tables below come from the our weather records.
Rainfall can vary considerably from one year to the next. At Hacienda Barú we have been recording the daily precipitation since 1981.During that time the driest year on record was 1997 with only 2622 millimeters (103 inches or 8 feet 7 inches), whereas the wettest year was 2010 with 7489 millimeters (295 inches or 24 feet 7 inches), almost 3 times as much. Nevertheless, most years the rainfall will be close to the averages shown in the table.
The temperatures shown here are averages. The extremes may be several degrees higher or
lower. For example the record high for the last three years was on April 14, 2016, 24.9 C°
(94.8 F°). Temperatures tend to be higher during the dry season January, February, March,
and the first half of April. Most years the rains begin in mid April and cool things down. The
record low during the last three years was on June 10, 2016, 21.2 C° (70.2 F°).