When vacationing in St. Lucia you'll very likely experience mild temperatures regardless of when you visit. In December, the temperature doesn't change much during the course of a typical day.

The daily high temperature averages degrees dropping to degrees late at night.

As shown above, during the first part of the month the low temperature averages degrees while the average daily high is degrees. If you visit during the middle of the month the daily low is typically around degrees while the daily high average around degrees. During the last part of December the lowest temperature reading averages degrees and the high temperature averages degrees. To learn more about temperature fluctuations during December in St. Lucia, study the table above.