How is the low temp recorded?

May 9, 2008 1:46:30 PM PDT
The low temperature usually happens right around sunrise.

Erica's Answer:

The thermometers that officially record high and low temperatures (most of these official reports come from local airports) have devices that get pushed up and down by temperature changes.

As the temperature drops at night, this little sliding bar is forced downward. As I mentioned before, the temperature usually bottoms out around sunrise. As the temperature starts rising again through the morning, that little sliding bar stays at the low point on the thermometer.

When a weather observer goes outside to the official reporting station, he or she can see exactly how low the temperature dipped during the overnight hours!

- Erica