Nevis is located about 17 degrees North of the Equator, to be more precise, 17.10N 62.35W. With such a great global position you can't help but have great weather. The days average about 84 degrees Fahrenheit, but are tempered by the steady Northeasterly breezes, and the nights are an insomniacs dream, with temperatures hovering around 73 degrees Fahrenheit This climate is incredible even by Caribbean standards.
There is very little humidity, cool sea breezes, and sunshine almost every day, Yes, there is rain, but it so soft and short lived that it is a treat instead of a force to be reckoned with. There are of course the odd hurricanes that blow through during the hurricane season (June 1 - November 30), but these are closely monitored by the National Hurricane Center, along with other tropical weather agencies, and won't pose much risk to the average tourist.
Yes the weather charts do say Saint Kitts and Not Nevis, this is however the Nevis forecast. It is just that the weather for Nevis is compiled about 5 miles away in St. Kitts, and is uploaded as such. If you click on the images below, you will see that its is Nevis weather information. One of these days maybe the weather bureau will give Nevis its own Nevis Weather image!