We have been there every February since 2012. The weather is nice (it's Hawaii, it's always nice) and only had one trip where the rain hung out almost the whole time. But hey, it's a warm rain, it empties out the pools, and if you're going to be playing in the water you'll be wet anyhow, so no big deal! In February the humpbacks are visible off the shore, and the waves on the North Shore are impressive. However, I will warn you, February can also be very crowded. February is typically when most of the schools (on the west coast it seems) take their mid-winter break. I've never not been there in February when it wasn't at capacity. However, I'm hearing that the resort is at capacity more than it isn't these days, so it may not matter. I also find airfare from Seattle to be more than twice what it is in the summer (again, it's known to be a school holiday time, so prices go up). February is a great time to be in Hawaii though!