Candidate Observatory Site:
Mauna Kea, Big Island of Hawaii


19 49 28.88 N, 155 28 24.12 W
(Copy and paste this location into or for images and maps of site.)


4050 meters (13,287 feet)

Site Description:

The candidate site is referred to as “13 North” (13N) on the northern shield, approximately 150 meters below the summit. It is adjacent to the Submillimeter Array (SMA) extension area. 13N is a high elevation site. It is a developed site with several observatories, so much of the infrastructure required for a new observatory already exists. Only a short piece of road would have to be constructed to the 13N site.

Site Images:

summit from the north east
View of the summit of Mauna Kea from the northeast, showing the many observatories already at the site. The proposed site N13 is the rugged plain visible just over the top of the twin Keck telescopes at middle right. The conical peak in the background is a dormant volcano, Hualalai. Note the haze and clouds that cover the lowlands. The summit of Mauna kea is usually above the wearther that affects the island’s lowlands. Image from the Univ. Hawaii, Inst. for Astronomy.

direct view of summit
This is a more direct view of the N13 site, at upper left center, on the plain where the dirt roads for the future Submillimeter Array fan out. Image from the Univ. Hawaii, Inst. for Astronomy.

summit from the south
This view of the summit is from the south, above the highway to the summit. This image gives a feel for the vertical topography of the site. Image from the Univ. Hawaii, Inst. for Astronomy.

For additional images of the summit of Mauna Kea, visit the University of Hawaii, Institute for Astronomy web site.


The conditions are usually dominated by a stable north-easterly flow, but the site does experience severe weather and precipitation, in particular in the winter.

Site Testing Information:

Since Mauna Kea is an established observatory site, data like those gathered during a testing run at a remote site are measured on a daily basis. Current conditions and forecasts of fog/precipitation, per cent cloud cover, summit temperature (high and low), precipitable water (in millimeters), seeing (in arc-seconds), and winds (miles per hour) are available at:

Historical summaries of these quantities can be found at the Gemini North web site.

Note: at this web site, “Measured Image Quality” is the seeing in seconds of arc.