If your at the beach a little sprinkle is normal, nobody gets up unless its enough to make your hair drip, besides you go to the beach to get wet anyway. Waikiki and Kaimuki are probably the driest spots on the island, if it rains there it is raining everywhere or it is just a passing shower.
The hotel across from the Ilikai, might have been the Big Surf hotel, it is very reasonable and close enough to the beach, they don't have a lot of amenities but I think it is where people who do a lot of travelling stay overnight for layovers.
The sun here is a lot closer to the equator, so sunscreen with the highest SPF you can get is best. You have to be careful not to fall asleep on the beach, it happens a lot. You end up with white lines where you wore your sunglasses. Spots on your face from where the sun poked through your hat, slipper lines on your feet, and if your hair is sparse on top and you don't wear a hat, a sunburned scalp.
We can always tell when someone has lived on the mainland awhile and either moved here or returned home. If they have a convertible they drive with the top down because it is sunny most of the time. Most people here would buy a truck but not a convertible, we actually need a roof to keep from getting burned.
December and January is Big Surf and when the surfing competitions are held. The dates are dependent on surf conditions they have to be high and clean enough. On those days, traffic slows to a crawl especially since Kam Hwy is one lane in either direction.
I have lived here all of my life and was never a good swimmer. I only went in the water when there were no waves. Now, that I have a bad rotator cuff, I don't even do that anymore. I used to go to my favorite park once a month. It is a state Park on the North Shore called Kaiaka park. It was mostly locals and the same people who went there all of the time. Losts of parking, open space for touch football and circular parking lot so I could ride my bicycle (I'm too scared to ride on the road). There is even camping space, near the shopping center, so we could get a plate lunch instead of packing the grill, tools, marinating meat, plates, etc. All we brought was a small cooler for drinks and snacks, my favorite book, chairs and a tarp for day camping. The park has only a small keyhole with a sandy bottom, the rest is rocky, but a good spot for fishing, although the fish weren't great for eating. Best of all the bathroom actually had doors on the stalls and toilet seats. There was a sink to wash the sand out of the suit and usually someone would bring soap and an old shower curtain for the shower. Sometimes someone would plug in a radio and even a rice cooker. Except for the pokies from the ironwood, it is the perfect spot to relax. I think everyone here has their favorite beach and we do have a lot to choose from. Some beaches are cleaner than others. Magic Island is man made so lots of sand and relatively shallow, but so many people, the restrooms are horrible and it is better if you bring your own soap and toilet paper. Parking is bad and there are just too many people there. You do need to be aware of beach conditions here some beaches are good for different activities but also have their dangers. There is a saying that anytime you enter the water, you are entering the food chain, so you need to know the risks.
The ocean moderates our temperature. The water can be cold but not freezing and sometimes it is very warm. Best of all it is available all year round.