River Temperature

Sampling Method


  • Alcohol Thermometer
  • Field Sheet and pencils

Measurement Protocol:

Air Temperature:
Hang or hold the thermometer by the end opposite from bulb in the shade for 5 minutes.

Read temperature to the nearest half degree and record on river field sheet .

Water Temperature:
Wade about calf-deep in the water at a representative, flowing-water location. Be sure not to disturb the site where you will take samples later.

Hold the thermometer by the end opposite from bulb so that the bulb is under water but not touching the river bed, for 2 minutes.

Quickly remove the thermometer from the water and read the temperature to nearest half degree.

Record temperature on river field sheet .

Quality Control

To ensure that field and lab thermometers are accurate, use a couple of quality control checks:

  1. Calibrate your thermometers yearly (or more often) against a Standard Thermometer - a thermometer certified by the National Institute of Standards and Technology. Professional labs have Standard Thermometers (EAL has one at UMass Amherst). To calibrate your thermometer, place it first in a room-temperature water bath along with the Standard thermometer. Take 10 separate readings of each thermometer over a period of time (say, one hour) and compare the means. Your thermometer should agree within 1 °C of the Standard thermometer. Then repeat this process using an ice water bath.
  2. Check your thermometer each day it's going to be used: Look closely at the thermometer to ensure that it is not cracked or damaged in any way and that the alcohol (or mercury) column is unbroken.