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In terms of precipitation, rainfall in Parnaíba ranges from 0.1 - 13.8 inches per month. April is typically the wettest month, when rainfall can reach 13.8 in. August is typically the driest time to visit Parnaíba when rainfall is around 0.1 in.
If weather is an important factor for your trip to Parnaíba, use this chart to help with planning. For those seeking warmer temperatures, October is the ideal time of year to visit, when temperatures reach an average of 86.0 F. Travelers looking to avoid the cold should look outside of July, when temperatures are typically at their lowest (around 78.8 F).