Average Aitutaki Weather in July
Daytime air temperatures in July hover around 81°F ( 27°C), usually falling to 72°F (22°C) in the night. July extremes of late have ranged from a max of 99°F (37°C) to a min of 60°F (16°C). Humidity will hover around 78% until a front rolls in and drives it up.
Water temperatures in the main lagoon will be very similar to air temperatures, averaging 79°F ( 26°C) with more extreme temperature fluctuation in the shallower shoals near mainland beaches.
We can expect to see at least some light drizzle every third day or so in July with the monthly rainfall total hovering around 79 mm (3 inches). Wind speeds will likely average 20 kph (12 mph) and peak as high as 50 kph (31 mph) if a storm blows through.
Current Conditions and Forecasts
The Cook Islands Meteorological Service is headquartered next to the end of the airport runway terminus on Rarotonga. There website tends to be light on details, but can be helpful and tends to load quickly. Note that some of the top level links on this website port directly to Maori language pages. If you get one of those pages, you will find a link on the left side of the page that renders the page in English (although the font tends to be small).
note that the wave height here refers to conditions outside of the lagoon.
Water Temperature in Rarotonga (Club Raro)
Water Temperature in Aitutaki (Matriki Beach Huts): see the very the bottom left of the page
Cook Island (Rarotonga) Tides
Here are the July and August 2015 tables: