There are a lot of ecological concern about the ecological impacts due to an artificial lake in Amazonia, especially related with the microclimate. This study aims to increase the scientific knowledge of the rainfall distribution prior and post flooding of the UHE Tucuruí-PA. Daily rainfall from 1972 until 1983 (prior inundation) and from 1984 until 1996 (post inundation) for Tucuruí and Marabá-PA. Comparing the monthly totals (prior and post), there is no statistical differences between the averages (using the statistical tests from Fisher and Man-Whitney). Analyzing the number of days with rainfall higher than 5 and 25 mm.day-1, there are also no statistical differences. It was observed a small increase of light rain during the end of the dry season. Also, the are no signal related to the modification of the onset or end from the rainy season.
rainfall; deforestation; statistical tests; Amazonia