Foi realizado um estudo visando comparar os ambientes de várzea sistematizada e de posto meteorológico, no município de Mococa (SP), por meio de medições de temperatura e umidade relativa do ar, radiação solar global e velocidade do vento. No ambiente de várzea, foi medido também o saldo de radiação. A comparação de médias foi feita por análise de dados pareados, de outubro a março (representando as condições de primavera/verão) e de abril a julho (outono e inverno). A evapotranspiração na escala diária foi estimada pelo método de Penman-Monteith, adotado como padrão pela FAO. No período outono-inverno (O-I), observou-se que, para a temperatura máxima do ar, a diferença média entre os ambientes foi de 0,1 ºC; para a temperatura mínima do ar, a várzea apresentou média inferior de 3,4 ºC, enquanto no período de primavera-verão as temperaturas máximas, na várzea, foram, em média, 0,9 ºC mais elevadas que no posto meteorológico. Os valores de evapotranspiração, no período de primavera/verão, os dois ambientes analisados foram muito semelhantes. A evapotranspiração em ambos os ambientes variou entre 1,0 e 7,8 mm por dia com valores máximos ocorrendo no período outubro/novembro. Durante o outono/inverno as estimativas feitas para o posto meteorológico foram superiores em 1,6 mm por dia às da várzea. No período de outono-inverno foram mais acentuadas as diferenças entre várzea e posto meteorológico.

A study was conducted to compare the systematic flood plain environment and that of a Weather Station. The survey was conducted in the Mococa county, São Paulo State, Brazil. The measurements of the microclimatic parameters at the weather station and floodplain environment were made by means of the automated weather station (SCI) determining: temperature and relative humidity of the air, and global solar radiation. In the floodplain environment the net radiation was also measured. The average values were compared by paired comparison analysis, for the months from October to March (representing spring and summer conditions) and the months from April to July (representing autumn and winter conditions).The evapotranspiration in the daily scale was estimated by the Penman-Monteith method adopted by FAO. During the autumn-winter (O-I) period, in the floodplain, it was observed that the average maximum air temperature were 0.1ºC and the minimum air temperature was found to be 3.4ºC lower than the weather station environment. During autumn-winter period the maximum temperatures, at the floodplain, were 0,9 ºC higher than the standard weather conditions. Considering the evapotranspiration in the spring/summer period, the values in the two conditions analyzed (station vs. floodplain) were very similar. Evapotranspiration in both environments varied between 1.0 and 7.8 mm/day with maximum values occurring during the October/November period. On the other hand, the estimates made during the autumn/winter period for the weather station were higher, than those made for the floodplain. In the autumn/winter period the evapotranspiration estimated for the station were mostly superior( 1.6 mm/day) to those of the floodplain. During the autumn/winter period the differences between the environment of flood plains and weather station were higher showing that for the floodplains the microclimatic parameters are more extreme than for the weather station.