Aruba is a constantly windy island that is located on the southern fringes of the Caribbean.  Although hurricanes occasionally menace the region during the Caribbean hurricane season, they rarely hit Aruba, since most hurricanes meander further to the north.  There is, however, still the possibility of quick moving storms passing over Aruba during the hurricane season.  These storms may actually reduce the easterly winds at times, which will cause you to feel hotter than usual, since it's the wind that provides respite from both the high Aruba humidity and temperatures.   If there's a hurricane nearby, the peripheral effects of the hurricane could cause dangerous surf conditions. 

With an average rainfall just over 20 inches, anytime of the year is perfect for a visit to Aruba. The so-called "rainy season" runs from late October into the beginning of January, but most of this rain falls in the form of short, sharp showers and mainly over night. December, on average the rainiest month of the year, typically records an average rainfall of 3.3 inches of rain versus May which receives only half an inch of rain.

Either way, there's no need to worry about being stuck in a hotel room staring at raindrops all day. Average day time temperatures during the summer months average 90° F and during the winter, an average of 86° F. Night time lows rarely fall below 80° F in the summer or 76° F during the winter. The only need for a sweater arises from the air conditioning when the restaurants or casinos get too chilly.

The sunshine in Aruba is very strong and the constant breeze is deceiving.  Sunscreen is imperative with 50 SPF for those who tan easily and 80-100 for those who burn easily.    

The local Aruba Meteorologic Service provide a 4 day weather forecast

If you require further information about the Aruba weather then you should follow the advice of the Aruba destination experts in the forums.