Rain falling before and during matches on Wednesday and Thursday could have a impact on the results of several key matches.
The matches most likely to be impacted by rain are taking place in Manaus, Porto Alegre and Recife.
All three of these matches feature teams that are fighting to advance from Group stage into the round of 16.
The Wednesday match in Porto Alegre between Nigeria and Argentina will have to deal with periods of rain and perhaps a thunderstorm. A soaking rain is expected leading up to the match Wednesday morning which will have a lasting impact on the playing surface regardless of how much rain falls during the match.
Later in the day, the match between Honduras and Switzerland, taking place in Manaus, will be at risk for a shower or thunderstorm. The heat will also be a concern for this match as competitors deal with the grueling conditions of the Amazon for 90 minutes.
Shifting to Thursday, all eyes will be on the early match up between the United States and Germany that will take place in the tropical city of Recife. A surge of tropical moisture leading up to the match will produce numerous showers through the day on Thursday. As a result, the playing conditions could affect the strategies of both teams as they face off in an attempt to move on to next round.
The other matches on Wednesday and Thursday will be largely rain-free, and temperatures are expected to be seasonable.