Average high temperature 89 F.
Average low temperature 80 F.
Average temperature 83 F.
Average water temperature 82 F.
Average rainfall 1.20 inches
Average windspeed 19 mph
There is very little difference in weather on Aruba. The end of October through mid-January is the rainy season, but Aruba is a semi-arrid island which receives a little over 22 inches of rain per year. For comparison, New Jersey receives on average about 42 inches of rain per year.
Rain in Aruba falls in the form of showers, mainly overnight or early morning. Daytime showers are usually quick passing clouds with excess moisture. It can very easily be raining where you are on the beach and be perfectly dry 500 feet away. We spent a week in Aruba during one September and had one day of clouds and showers during the entire week. Remember showers are just that, showers. With the exception of when there are tropical waves or tropical depressions in the area or nearby it is rare to get an entire day which is a "rain out". See more below about tropical weather during hurricane season.
We were in Aruba December '07 for 12 nights and I was concerned beforehand about the possibility of being rained out. My worries were for naught. We have rain every morning but 2, and then the sun was out and shining brightly by 10 a.m. One day was overcast with a couple of afternoon showers and another day we had off and one drizzle with clearing at about 3 p.m. One day we toured the island and the other day we snorkeled.
"Q. Does Aruba have a rainy season?
The leeward islands of the Dutch Antilles (Aruba, Curacao and Bonaire) have a semi-arid climate (yearly precipitation is about 550 mm [22.7 in.] per year). This is due to an extension of the Azores high and locally it is also connected with an upwelling zone with colder sea surface temperature (SST) along the east-west Venezuelan coast caused by the easterly trade winds (Lahey, 1958; Trewartha, 1981). The influence of the mainland 60 km away is large: during the rain season most precipitation is late at night and in the early morning, opposite to the usual tropical pattern, which exists on the mainland. This is caused by the sea-continent breeze...Traditionally, the year is divided in three 4 - month seasons."
Rainy season can be broken down as follows:
February to May is dry season.
June to September is the "small rains" season.
October to January is the rain season.
Just so folks know I don't pull this info out of a hat...Source Predicting rainfall in the Dutch Caribbean | more than El Ni~no? http://www.meteo.an/include/Pub/documents/curacao.pdf
Hurricanes and Tropical Storms in the Netherlands Antilles and Aruba www.meteo.an/include/Pub/documents/HurricanesandTropicalStorms.pdf
"Hurricane climatology of the Netherlands Antilles and Aruba p. 17
"The Leeward (ABC) Islands
Aruba, Bonaire and Curaçao are on the southern fringes of the hurricane belt. They are not outside the hurricane belt, as many consider. History learns that roughly once every 100 years considerable damage is experienced by tropical cyclones passing over or just south of the islands. Although the hurricane experience level for the islands may be regarded as very small, well known is the minor hurricane which passed just south of Curaçao on September 23, 1877 causing an estimated structural damage of US$ 2 million, mainly to the coastal section of Willemstad. A nunnery was completely washed away (remnants still visible with low tide), many ships were lost and at least 70 persons drowned. The lowest barometer reading at Willemstad was observed at 15:30 UTC on September 23 (UTC = local time + four hours in Eastern Caribbean Area) with 995.4 millibars. A ship sailing south of Curaçao reported a lowest pressure of 988.8 millibars.
On the average, once every four years a tropical cyclone occurs within a radius of 150 kilometers, but mostly passing to the north of the islands without causing serious bad weather. Even the immediate effects of major hurricane Hazel, of which the center passed approximately 90 kilometers to the north on October 7, 1954, with maximum sustained winds near the center of 190 km/h, were confined to observed maximum winds of 50 km/h with gusts to 90 km/h, and the damage, an estimated US$ 350.000,-, resulted mainly from flash floods due to heavy rainfall (48 hours averages: Aruba approx. 250 mm, Bonaire and Curaçao approx. 125 mm)."
Imo, go and enjoy without any frets over the weather.