Visit the Volcano!
The Hawaii Volcanoes National Park is open 24 hours a day, year round. It is also home to the Kilauea Visitor Center, and the Jaggar Museum where you can get a little schooling and culture on the volcano. Please note that there is an entrance fee to the national park. The entrance fee will cost you $10/car (including all passengers) and is good for 1 week.
Some fun things to do while in the Volcanoes National Park is to drive the Crater Rim Drive as well as the Chain of Crater Road. At this point in time, part of the Crater Rim Drive is closed due to volcanic activity (between the Jaggar Museum and the Chain of Craters Road junction), but things may change between now and September. Other great places to visit in the park are the Kilauea Visitors Center, the Volcano Art Center & the Volcano House Hotel (which is conveniently located right along the Earthquake Trail, or is it the trail that is conveniently located at the exit of the hotel? I guess thats up to each persons perspective!)
Unfortunately at this time, you are unable to hike out to the surface lava flows easily. If you are an avid hiker and want to torture yourself, you are welcome to back pack out to the lava flow from the end of the Chain of Craters road. For the experienced hiker, you are looking at a 9-11 mile round trip hike. 9-11 miles round trip, no sweat you may say Just take a word of advice, 8 years ago Corey and I make a similar hike out to the surface flows from the end of the Chain of Craters Road. Our round trip was maybe 4-5 miles. Those 4-5 miles took us a good 8+ hours (granted there was some serious goofing off involved, but a good portion of the time spent was walking) to make it there and back. Choose wisely about your course of actions because the hike is now days, is not just 8 hours.
Here also is a list of a few hikes available in the park for your perusal.
And on one last note, good news is you can currently see the lava flowing into the ocean (aka fire hoses)! Hawaii County has opened up a public viewing area of the lava flow. Make sure to check the current conditions by calling (808) 961-8093. The viewing area may be closed due to hazardous weather conditions.