Yellowstone Geyser Temperature

Yellowstone National Park is one of the most geothermally active places on Earth, sitting atop a vast supervolcano that fuels thousands of hot springs, mudpots, fumaroles, and—most famously—geysers. The geysers of Yellowstone are not only awe-inspiring to watch, but also fascinating in their internal power. 

Most of these geysers have water temperatures close to the boiling point, which in Yellowstone’s high elevation (around 7,000 feet) is about 199°F (93°C). What makes each geyser different is how deep its underground plumbing system is, how much pressure builds up, and how often eruptions occur. Below is a detailed look at the most famous geysers in Yellowstone and their temperatures.

Quick Reference: Yellowstone Geyser Temperature

Geyser Name	Location	Approx. Surface Temperature (°F/°C)	Max. Subsurface Temperature (°F/°C)
Old Faithful Geyser	Upper Geyser Basin	204°F / 96°C	240°F / 115°C
Steamboat Geyser	Norris Geyser Basin	200°F / 93°C	250°F+ / 121°C+
Castle Geyser	Upper Geyser Basin	200°F / 93°C	230°F / 110°C
Grand Geyser	Upper Geyser Basin	199°F / 93°C	220°F / 104°C
Riverside Geyser	Upper Geyser Basin	200°F / 93°C	215°F / 102°C
Great Fountain Geyser	Lower Geyser Basin	199°F / 93°C	230°F / 110°C
Daisy Geyser	Upper Geyser Basin	200°F / 93°C	215°F / 102°C
Lion Geyser	Upper Geyser Basin	199°F / 93°C	220°F / 104°C
Echinus Geyser	Norris Geyser Basin	185–199°F / 85–93°C	220°F / 104°C

Old Faithful is the most famous geyser in the world and the crown jewel of Yellowstone’s Upper Geyser Basin. The temperature of Old Faithful’s water near the vent is around 204°F (96°C), just slightly above boiling due to pressure underground. However, deeper in the vent system, temperatures can reach up to 240°F (115°C) before eruptions. This intense heat causes the water to flash into steam, creating the iconic eruptions that can last from one and a half to five minutes and reach heights of 100 to 180 feet.

Steamboat Geyser in the Norris Geyser Basin is the tallest active geyser in the world and one of the most unpredictable. Temperatures at the surface hover around 200°F (93°C), but deep underground they can soar well above 250°F (121°C). When pressure builds up enough, Steamboat’s eruptions can shoot boiling water up to 300 feet into the air. Between major eruptions, steam continues to hiss and bubble from the vent, showing how volatile and hot the system remains even at rest.

Castle Geyser, located near Old Faithful, is another prominent feature in the Upper Geyser Basin. The temperature of the water in Castle Geyser’s vent typically reaches 200°F (93°C) at the surface. Castle’s plumbing system is older and more complex than many other geysers, which causes its eruptions to be less frequent but longer-lasting. Eruptions can last up to 20 minutes, and during this time, superheated steam continues to escape long after the water has stopped gushing.

Grand Geyser, also found in the Upper Geyser Basin, is known as the tallest predictable geyser in the world. The vent temperature averages around 199°F (93°C), but just below the surface, the temperature rises to over 220°F (104°C). Grand erupts about every 7 to 8 hours, sending boiling water as high as 150 to 200 feet. The pool’s shimmering surface before each eruption often gives off a visible heat haze, a sign of the extreme temperatures just below the ground.

Riverside Geyser, positioned along the Firehole River, presents a unique spectacle where the geyser’s 200°F (93°C) water erupts gracefully in an arc over the river. Its consistent temperature and regular eruptions make it a favorite among visitors. The interaction of hot geyser water with the cool river creates clouds of steam that rise beautifully into the crisp Yellowstone air.

Great Fountain Geyser, found in the Lower Geyser Basin, erupts from a large pool surrounded by terraced formations. The water temperature in the pool averages around 199°F (93°C), while deeper vents maintain higher temperatures close to 230°F (110°C). Before eruption, the pool overflows with hot water, creating a mirror-like reflection that hides the power bubbling beneath.

Daisy Geyser, also in the Upper Geyser Basin, has a vent temperature of approximately 200°F (93°C). It erupts at a 70-degree angle, sending boiling water up to 75 feet into the air every two to three hours. The geyser’s consistent cycle and predictable heat make it one of the most reliable geysers to witness.

Lion Geyser, part of the Lion Group near Grotto Geyser, maintains surface water temperatures close to 199°F (93°C). Its roars, produced by escaping steam, can be heard even before the eruption begins. The combination of heat, pressure, and steam channels beneath the ground make it one of Yellowstone’s most vocal geysers.

Echinus Geyser in Norris Geyser Basin is the largest acidic geyser in Yellowstone, and its water temperatures vary from 185°F (85°C) to 199°F (93°C) depending on underground conditions. Its eruptions are less frequent today, but its unusual chemistry and scalding acidity make it one of the most unique thermal features in the park.

In essence, nearly every geyser in Yellowstone operates just below or at the local boiling point of water, around 199°F (93°C). The incredible diversity of eruption styles—from the roaring blast of Steamboat to the gentle gush of Riverside—is the result of small differences in heat, water supply, and underground structure. Understanding these geysers’ temperatures helps visitors appreciate how close they stand to nature’s raw geothermal power.