U.S. Virgin Islands · St John
Trunk Bay
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Air
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Climate · monthly averages
Sea temperature by month
30-year averages (1996–2025). Min/Max are typical daily lows and highs, not record extremes.
72°F
75°F
79°F
82°F
86°F
90°F
93°F
January
79.9°F(79°F–81°F)
February
79.2°F(78°F–80°F)
March
79.2°F(78°F–81°F)
April
80.1°F(79°F–82°F)
May
81.5°F(80°F–83°F)
June
82.8°F(81°F–84°F)
July
83.1°F(82°F–84°F)
August
83.9°F(83°F–85°F)
September
84.5°F(84°F–86°F)
October
84.4°F(83°F–86°F)
November
83.1°F(82°F–84°F)
December
81.4°F(80°F–82°F)
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MinMin °F | 7979.0 | 7878.2 | 7877.8 | 7978.9 | 8080.5 | 8181.5 | 8282.1 | 8382.9 | 8483.8 | 8383.5 | 8282.1 | 8080.0 |
| AvgAvg °F | 8079.9 | 7979.2 | 7979.2 | 8080.1 | 8281.5 | 8382.8 | 8383.1 | 8483.9 | 8584.5 | 8484.4 | 8383.1 | 8181.4 |
| MaxMax °F | 8180.9 | 8080.3 | 8180.7 | 8281.5 | 8382.9 | 8484.1 | 8484.5 | 8585.2 | 8686.1 | 8685.5 | 8484.1 | 8282.3 |
Warmest in September (84.5°F). Coldest in February (79.2°F). Comfortable for swimming year-round.
About Trunk Bay
On the north shore of St. John inside Virgin Islands National Park, Trunk Bay holds one of the world's earliest underwater snorkeling trails, with submerged interpretive signs guiding swimmers through a protected reef named for the leatherback turtle. Further east in the same park, Cinnamon Bay opens a long crescent of pale sand, while Maho Bay stays shallow and calm enough for sea turtles to graze on seagrass. Water holds 28 to 29 °C from July through September; Cyril E. King airport on St. Thomas is roughly 45 minutes by ferry and road.