ICOADS is the largest collection of marine surface in situ observations with over 200 million records from 1784 through the current date. ICOADS is formed by merging many national and international sources that contain measurements and visual observations from ships (merchant, navy, research), moored and drifting buoys, coastal stations, and other marine platforms. Each report contains individual observations of meteorological and oceanographic variables, such as sea surface and air temperatures, wind, pressure, humidity, and cloudiness. The coverage is global and sampling density varies depending on date and geographic position relative to shipping routes and ocean observing systems.

ICOADS is the result of a long-standing (beginning in 1981) cooperative project among the NOAA Earth System Research Laboratory, NOAA National Climatic Data Center, and NSF National Center for Atmospheric Research. Recently, many international partners have been contributing to ICOADS by, providing additional data, adding metadata, and supporting the project in international forums. Systematic quality assurance, processing into a uniform data format, and unrestricted distribution make the dataset a significant and often cited archive.

In an important, related dataset, ICOADS observations are statistically summarized on a monthly basis and in one-degree or two-degree latitude by longitude squares. The monthly summary statistics are also available , as is much more information on the ICOADS project website

IMPORTANT notice about the ICOADS time period

• The official Release 2.4 period is 01/1784 through 05/2007
• All data following the end date of Release 2.4 should be considered preliminary and are subject to change