by Kim Kastens and Song Leav
This page contains data on water temperature of Nagog Brook, collected at the Green Acton stream monitoring station. Nagog Brook data are automatically collected every 15 minutes with a Tidbit sensor, and are shown as a solid blue line on the graphs below.
For comparison, the average air temperature on each day is shown as a red dot. Air temperature data come from Hanscom Field in Bedford, chosen because it has a continuous record of reliable data and is reasonably close by. In general, the air temperature is more volatile than the water temperature. That means it changes more from day to day, from day to night, and from winter to summer than the water temperature does. This is further explained in the post “Nagog Brook Temperature: Warm in Winter, Cool in Summer.”
Another useful comparison is to fish habitat conditions. The warmest recommended temperature for brown trout is 23.9°C (75°F), and the warmest for brook trout is 20.0°C (68°F) (OARS annual report).
Each graph shows one year of data, with the oldest at the top and the newest at the bottom. Data for coming years will be added to this page as they become available. All years are plotted at the same scale to facilitate year-to-year comparison. The first year (2017) doesn’t have a complete year of data because we started data collection in July. To see the data at larger scale, click on the graph.
