Timeseries: down/upwards - Long-term daily stream temperatures

A tile map of the U.S. showing mean daily stream temperature for the 5 USGS stream sites with the longest daily temperature records in each U.S. state. The oldest site, in Philadelphia, Pennsylvania, began collecting data in October 1964. For each state, a line chart shows the mean daily temperature for each day of year, averaged over the period of record for each site. Stream temperatures in most states are between 0 and 20 degrees Celsius in winter months, and peak around 30 degrees Celsius in the summer. Sites in some states display different patterns. For example, at the Hawaii sites, stream temperature remains around 25 degrees Celsius year-round. At the Alaska sites, summer temperatures peak around 12 degrees Celsius.