Boothbay Harbor Environmental Data

Available Data rocky Maine coast

The Boothbay Harbor (BBH) Sea Water Temperature Record, extending over more than a century, constitutes one of the longest running, continuous series of sea temperature observations for any point on the North American Atlantic Coast. Observations began in March 1905 and have continued, with minimal interruption, to the present day.

Currently, observations of air temperature, barometric pressure, sea surface temperature, relative humidity, wind speed, wind direction and dissolved oxygen are recorded at daily intervals. Starting in 2020, the partial pressure of carbon dioxide and pH will also be recorded at daily intervals. Daily/monthly/annual summaries of BBH Environmental Data can be obtained by contacting Jesica Waller.

Daily sea surface temperature data are available below at our Open Data Portal, or in PDF, CSV (comma-separated values) or XLSX (Microsoft Excel) format. PDF files may require Adobe Reader software (download here, free).  Please contact Jesica Waller if you require an alternate format.

Station History

In 1905, the U.S. Bureau of Commercial Fisheries began the Environmental Monitoring Program at the fish hatchery in Boothbay Harbor. Air and sea surface temperatures were recorded three times daily from 1905 until 1949, when instruments were installed and data were recorded continuously on strip charts. Environmental observations were expanded in the 1960's to include other physical oceanographic and meteorological variables in addition to temperature. In 1973, the program was transferred to the Maine Department of Marine Resources and computerized data collection, processing, and storage began in 1986. Sensors for air temperature, sea surface and bottom temperature, relative humidity, and tide height as well as datalogger hardware and software were installed in 1996. The system was upgraded again in the summer of 2012. Currently, observations of air temperature, barometric pressure, sea surface temperature, relative humidity, wind speed and wind direction are recorded daily intervals. All data are provided upon request to the public, news media, and university and government researchers.

Boothbay Harbor stationStation Description

The Environmental Monitoring Program is operated by the Maine Department of Marine Resources with the goal of maintaining a continuous source of high-quality physical environmental data for the Maine coast. The station is located at the Department's Fisheries Laboratory in West Boothbay Harbor, Maine (43°50'40" N, 69°38'30" W). All of the station's sensors are deployed at or near the laboratory pier in a sheltered cove on the west side of Boothbay Harbor. The main harbor is very sheltered and the cove is more so. Wave heights during a severe storm may reach three or four feet in the main harbor but rarely reach even two feet in the cove. Mean tide range has been calculated by the National Ocean Service at 8.8 feet and the spring tide range is given as 10.1 feet. While the harbor typically remains open throughout the year, the cove often develops a thin layer of ice which would extend from shore to shore if it weren't broken up by the passage of various small vessels. Freshwater influences within the harbor consist of a few small streams which provide drainage for the immediate area. Two larger rivers, the Sheepscot to the southwest and the Damariscotta to the northeast, are nearby.

wavesThe sea surface temperature sensor is located at -5.5 feet MLW (relative to mean low water). Air temperature and relative humidity sensors are mounted on the dock in a down-looking radiation shield. Wind speed/direction are tower mounted on the dock approximately 30 feet above sea level. However, both the eastern and western horizons are obscured slightly by the Boothbay Harbor Laboratory and trees.

Statistics Reported

Several statistics are calculated and stored in the Department’s database. Daily minimum, maximum and average readings for air temperature, sea surface temperature, wind speed and barometric pressure are stored. Wind direction and relative humidity are also stored.