Hot ponds and hot springs

The 2018 lower Puna eruption buried the two warm ponds everyone used to visit, ʻAhalanui and the Kapoho tide pools, under fresh lava. So if you are asking whether you can still find a hot spring on the Big Island, the answer is yes, but barely. One remains: the Pohoiki warm ponds at Isaac Hale Beach Park in the Puna district, formed when the 2018 lava berm trapped geothermally heated spring water against the new black-sand beach.

That makes Pohoiki the only easily accessible option, and it is not the cleanest. The ponds are not disinfected, there is no routine water-quality testing, and the bacterial risk is real enough that you should not soak with any open cuts. The park itself closed for a failed boat-ramp dredging project in 2025 and reopened that December, with the warm ponds still accessible.

Bathing with broken skin is not advised at any of these ponds. The cleanliness tradeoff is real, so it is worth reading the safety and hygiene section before you go.

Pohoiki: the only hot spring left on the Big Island

The Pohoiki warm springs are part of Isaac Hale Beach Park on the Puna coast, and after 2018 they are the one volcanically heated soak still open to the public. The water runs warm rather than hot, roughly 90 to 100°F, warmed by residual heat from the lava that reshaped this coast. The park reopened in December 2025 after a closed season for a boat-ramp dredging project that did not work, so the ocean launch is still buried even though the ponds and beach are open again.

The same eruption gave Pohoiki the newest black-sand beach on the Big Island, ground down from the basalt the lava left behind. It is worth the walk to the shoreline even if you skip the soak.

Looking back from the black sand at Isaac Hale Beach Park: the lifeguard tower, the warm ocean thermal pond near the boat ramp, and the parking area are all visible. The solidified lava along the coastline marks the edge of the 2018 Kīlauea flow that created this beach.

The ponds formed where the new black-sand berm trapped heated spring water behind it. A January 2020 USGS survey mapped five warm-to-hot pools across the park, shown in the aerial image below. Their temperature has held in the warm range in the years since, though it shifts with the tide. You can read more on how the Pohoiki springs developed at the Hawaii Tracker website.

1. A pond adjacent to the lava flow on the far eastern edge of the beach
2. A pond that has formed at the location of the old boat ramp
3. A pond at intersection of the new beach with the old coastline at the previous location of ‘1st bay’
4. The previously already existing warm pond in the forest that has now heated up more
5. A pond at intersection of the new beach with the old coastline at the previous location of ‘2nd bay’

The 5 hot springs at Pohoiki. In this aerial picture of the new black sand beach at the Isaac Hale Park taken on 21 January 2020 you can see that the basaltic sand from the 2018 lava delta (right) continues to accumulate, both widening and elongating the beach in Pohoiki Bay. Image credit: USGS (public domain)

These ponds are not disinfected. Skip them if you have any open wound, and read the safety section below before you get in.

How to visit Pohoiki: parking, drive times, and what to bring

Pohoiki sits at the end of Highway 137, the coastal Red Road in lower Puna, about an hour from Hilo and roughly two and a half hours from Kona. Isaac Hale is a county beach park, so there is no entrance fee, and there is a paved lot.

Facilities are basic: there is a lifeguard, restrooms and a few picnic spots. Bring a towel, drinking water, water shoes for the rough lava rock, and a dry change of clothes. Skip the sunscreen and lotions right before you get in, since whatever is on your skin ends up in a small, slow-moving pond that everyone else is sharing.

Is the water clean? Safety and hygiene

Honestly, no, not in the way a pool is. The Pohoiki ponds are not disinfected and get no routine water-quality testing, and bacterial counts in Puna warm ponds have historically run past EPA and state guidelines (source). The mix of warm, slow-moving water, heavy use, and limited sanitation in the area is what drives that.

The Department of Health warns that the ponds are not disinfected and that the public should not enter with open wounds, given the risk of bacterial infection. Enter at your own risk. Hundreds of people use the ponds on a busy day without trouble, but as a visitor you are more likely to be vulnerable to the local bacteria than a resident who soaks here often.

• Don’t enter the water if you have an open cut or infection.
• Keep your head above water and try not to swallow any.
• Avoid crowds: stay away on weekends and go early, after the overnight tide has flushed the ponds.
• Shower and rinse off once you get out.

You can find water quality advisories for the state of Hawaii here.

What happened to ʻAhalanui and Kapoho

Two of the Big Island’s best-known warm-water spots are gone. The 2018 lower Puna eruption buried both the ʻAhalanui warm pond and the Kapoho tide pools under lava within weeks of each other, which is why Pohoiki is the only one left. Here is what they were, for context and for anyone working from an older guidebook.

ʻAhalanui Warm Pond (destroyed in 2018)

ʻAhalanui park was the county beach park built around the warm pond, with a picnic area, showers, and restrooms. It drew big local crowds, especially on weekends, and the quiet window was a weekday morning before 9 a.m.

The ʻAhalanui hot pond in the Puna district on the Big Island, Hawaii, before it was buried by lava in 2018. The pool was partly walled off from the ocean to create a lukewarm swimming pool.

The Kapoho tide pools (destroyed in 2018)

The Kapoho tide pools went by the official name of the Waiʻōpae Tide Pools Marine Life Conservation District, about 1.5 miles north of the ʻAhalanui warm pond. (Waiʻōpae means “shrimp water” in the Hawaiian language.)

They were a difficult-to-reach snorkeling spot in Kapoho Bay that earned a spot in almost every guidebook. Some of the pools were heated by warm water seeping out of the lava rock, which is what put this snorkeling spot on a list of Big Island hot springs in the first place.

The Kapoho tide pools and the Kapoho Vacationland subdivision, before the 2018 lava flow. Image credit: google maps

A basalt ridge offshore sheltered the pools from the surf and let the tide flush them with fresh seawater twice a day, conditions that built one of the highest, most diverse coral covers on the east side of the island.

The Kapoho tide pools were located in front of the Kapoho Vacationland subdivision. USA – Hawaii / Big Island: Kapoho Tide Pools, CC BY-SA 2.0, Link

Read more about the Kapoho (Waiʻōpae) tidepools at the hawaii.gov website.

You can get an impression of what the Kapoho tide pools were like from the following video:

What makes the springs warm?

The heat here is volcanic, not solar. The water that fills these ponds starts as rain and picks up its warmth underground, on the way to the coast.

It rains a lot on the windward (East) side of the Big Island, up to 300 inches (10 meters) per year. Most of that water does not run straight to the ocean but sinks into the ground until it hits a barrier. On the Big Island that barrier is salt water, which is heavier than fresh water, so the fresh water rides on top of it and works its way slowly out to the edge of the island.

In the volcanic areas of the Big Island, that water passes through rock heated by magma in the lower East Rift Zone. The rock hands its heat to the water, which carries it toward the coast. As the water moves away from the magma it cools a bit, especially where cold water mixes in, but it stays warm enough for a comfortable soak by the time it surfaces near the shore.