Weather on St. John
We like to tell most people, the weather on St. John is consistently low-to-mid 80°F with a brief shower once in a while. Other than late summer (Aug-Sep), there is typically a consistent breeze blowing which makes air conditioning optional at our villa.
Similarly, the average water temperature is between a low of 80°F in the winter months to highs of 84-85°F in the summer.
In a nutshell, it’s wonderfully warm almost every day and perfect weather for shorts and short sleeve light shirt or a skirt/dress. There are maybe 10-20 nights a year where the weather dips into the low 70’s F and locals can be seen wearing longs sleeves or even a sweatshirt.
Similarly, the water temperature around St. John varies between 79°F and 85°F depending on the season. We like to use a day at Maho Beach as an example of how the water temperature changes
In the winter months, you’ll be sunning yourself and cooling off in the bay for maybe 10 minutes to a half hour.
In the summer, you might put a hat on and sit neck deep in Maho for half the day or more.
We have had guests who call or email after pulling up their smartphone weather app saying "it's going to rain every day while we are there next week!" It isn't. The apps show the probability of rain and very little about whether it is going to rain for 2 minutes or 8 hours. It rarely rains for hours on St. John.
Live St. John Weather Monitoring
In the summer of 2018, we installed a live weather station on the roof of the guest house. It not only submits live St. John weather data to Weather Underground, it also stores the data in the ‘cloud’ so we can show you this live embedded data straight from Great Expectations on St. John’s south shore.