Many weather enthusiasts have a thermometer like the one shown in detail below.The lower end of the black pin on the left marks the minimum temperature that has occurred since the instrument was last reset.(in this case 16 degrees). The lower end of the pin on the right(showing a temperature of 28) marks the maximum temperature.The narrow piece of plastic in the centre of the thermometer is pressed to reset the pins.The top of the column of silver liquid shows the current temperature (22.5 degrees).Thermometers should be placed where the sun never shines on them, but not in the most shaded spots. This is why official weather stations use a Stevenson Screen, out in the open. Thermometers like the one shown, are readily available in most Garden Centres at a relatively low cost.