Hawaii in February with 12 & 14 year olds?

If you're not beachgoers or ocean lovers, not sure you'd get your money's worth out of a trip to Hawaii. Also, each island is different. Kauai and the Big Island probably have the most selection of hikes, and the Big Island is the one with current volcanic activity, sort of, you have to check the NPS site for the current updates and it's a very fluid (ha ha) situation that changes in terms of public access. Finally, I have considered going in February before, but always concluded losing that extra hour or two of sunlight makes it less cost-effective. I love Hawaii, literally just got back from a week in Maui, and would go again in a heartbeat, but it is expensive - both the flights and the cost of living there, so you really want to be confident you'll get your money's worth. We love to snorkel and it's fantastic for that.

We stayed at a place on Champagne Pond on the Big Island on a February trip and found it a lovely, drama-free launch explorations.  We found it via VRBO or homeaway but then rented it cheaper though a property management place... so we learned to look for places on multiple listing services as prices for the same place can really vary!  While Champagne Pond was quiet, it is also remote - there is no breakfast service without a drive back to the small town.

If you want volcanos, you want the Big Island (Hawaii). Hawaii Volcanoes National Park is the place to go for volcanic activity. Things can change dramatically over time, but it is my understanding that there is currently a lava lake in the Halema'uma'u crater. I was there four years ago, and the glowing red plume from the crater was pretty dramatic. You can hike across the Kilauea crater with its steam vents, explore Thurston Lava Tube, and visit more craters than you can shake a stick at on Chain of Craters road. There is a hike to a field of pictographs, If you're lucky, there may be surface lava flows within hiking distance.

Definitely try snorkeling--the underwater sights are amazing, with the west side of the big island having unbelievable clear water and an abundance of colorful tropical fish. You can kayak from Napoopoo to Captain Cook Monument, which is known as a great snorkeling location. I signed up for an organized kayak tour, which was great (I think the company I used is no longer in business). Rainbow falls, Akaka falls, Kiholo Bay, and Kaumana caves are awesome. The top of Mauna Kea is eerily alien and very cold if you are inclined to brave the altitude. For history, Pu'uhonua O Honaunau, the aforementioned pictographs, Pu'ukohola Heiau, Mo'okini Heiau, Laupahoehoe, and the Pacific Tsunami Museum. Ten of the world's 14 different climate zones can be found on the Big Island. It is truly amazing. 

On one two-week trip with husband, mom, aunt, and brother, we rented houses or condos in three different locations around the island. We used VBRO. Sorry, no specific recommendations as the place I liked in Honomu doesn't seem to be listed any more. But I definitely recommend choosing at least two base points around the island. It is a long drive from the west side of the island to the east, and many visitors end up giving short shrift to the volcato (southeast) and east side of the island (much less touristy with a larger local population) by trying to do everything out of one resort on the Kona coast.

There are more amazing places on the island than I could possibly list here. I highly recommend the book "Hawaii: The Big Island Revealed" by Andrew Doughty. It doesn't stint on the islands many historic and natural attractions, far beyond beaches.

I think you would like the Big Island. Because it is the newest island, there aren't a lot of sandy beaches, so it isn't the white sand vacation spot that a lot of people look for in a Hawaii trip. It's also pretty rural, but that makes it feel very relaxing. We always stay on the Kona side near Captain Cook because an old friend of mine lives there. One place we stayed that we really liked was called Aston Kona by the Sea. It's a small 1960s-style condo complex on the rocky shore and has large comfortable rooms and is close by some good snorkeling beaches. City of Refuge is a short drive away and is a wonderful place to spend the afternoon walking around. There are many small rocky beaches tucked in here and there where people go snorkeling or just look at the sea. If you want to buy some flipflops or a muumuu you can drive up the road a bit to Kailua Kona and have a low-key Hawaiian tourist experience.  I really like the Kona side.

Usually we go to Volcano National Park for a couple days. It's hard to drive there and back on the same day from Kona, so it's worth spending a night or two in Volcano.  There are lots of places in the park to hike and explore, from active distant steam vents to a walk around the caldera to fern-lined trails through lava tubes!  When we were there last year, Kilauea was active -- going to see it at night was just spectacular, and there is a very good observation area with a visitor center where you can look from afar. There is also a lodge inside the park where you can have a nice dinner overlooking the caldera or stay there overnight - I've never had good luck finding anything on AirBnB in or near Volcano so maybe the lodge is the best bet.  

I also like visiting Hilo. It's the biggest city on the Big Island but it feels more like a small rural cowboy town.  It's very green and lush. There is a fantastic tsunami museum in Hilo that's well worth a visit, and the Hilo bay is really pretty, with lots of people on paddle boards - that might be a fun activity for your teens. Not too far from Hilo is another volcano - Mauna Kea. It is so tall that it has snow on top and you drive through the clouds to get to the visitor center. Further up is the observatory which you can also visit but the altitude is really intense.  I have not hiked in that area but I'm sure there must be trails.

And there is also really great snorkeling on the Big Island! You can rent gear there. I don't much like traipsing around on coral and sea urchins but I'm really glad I got to see what it looks like underwater - it takes your breath away (no pun intended.) 

On the Big Island there is also a resort area called Waikoloa which I tried a few years ago when my kids were little and they just wanted a giant swimming pool and unlimited (expensive) burgers. We haven't been back, but it's there for people who like the resort scene! There are also many interesting places to explore, such as the birthplace of King Kamehameha which is in the middle of nowhere on a windy plateau overlooking the Pacific Ocean.  I think that would be an interesting place to hike!

Enjoy your vacation.