40°08′15″N 105°14′16″W / 40.137558°N 105.237875°W / 40.137558; -105.237875 Boulder Geomagnetic Observatory (BOU) is a geomagnetic observation facility operated by the United States Geological Survey (USGS). It is located near Boulder, Colorado at 40°08′15″N 105°14′16″W / 40.137558°N 105.237875°W / 40.137558; -105.237875. The site was established in 1961.

Customers of the observatory include the Space Weather Prediction Center (SWPC) and the Air Force Weather Agency (AFWA).

• A magnetometer
• A solar proton sensor

• Space weather
• Heliophysics
• K-index

• Boulder (BOU) Geomagnetic Observatory website
• Boulder USGS Magnetometer Monitor

 This article incorporates public domain material from websites or documents of the United States Geological Survey.