If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Osasco: The hottest months are usually February and January, with an average temperature of 22°C, while the coldest months are July and June, with an average of 17°C. The rainiest months in Osasco are January, December, February and November, with each month seeing an average of 213 mm of rainfall.