Weather will likely play an important role when you plan your trip to Kwajalein, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually September and August, with an average temperature of 28°C, while the coldest months are February and January, with an average of 27°C. The rainiest months in Kwajalein are November, October, September and August, with each month seeing an average of 324 mm of rainfall.