When To Go · Destination Guide

St Thomas and St John

Ferry-linked Caribbean reefs, St John park snorkeling and local day-boat diving

When to go

Best time to visit St Thomas and St John

A broad trip is easiest to plan in the relatively drier December to April period, but cold-season north swell can make some of the most famous St John snorkeling bays unsuitable on a given day.

Best overall window

December to April

Relatively drier season for island travel, yet winter north swell and holiday boat/road demand can still disrupt north-shore water plans.

Outside that window

Warm, often humid and vulnerable to tropical systems; peak climatological storm risk is late summer to early autumn. Trips may still operate but need flexibility.

Choose your trip style

Start with the overall answer, then switch only when scuba, freedive, snorkel, or topside timing changes the trip in a meaningful way.

Month-by-month planner

The overall row stays visible so you can compare it against the currently selected scope.

BestGoodTradeoffsMore variable

Scope	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Overall	Overall - Jan: Best	Overall - Feb: Best	Overall - Mar: Best	Overall - Apr: Best	Overall - May: Good	Overall - Jun: Good	Overall - Jul: Tradeoffs	Overall - Aug: Tradeoffs	Overall - Sep: Tradeoffs	Overall - Oct: Tradeoffs	Overall - Nov: Good	Overall - Dec: Best

Wildlife goals and seasonal highlights

These do not replace the overall planner. Use them only if a specific animal or event is driving your trip dates.

Green turtles feeding over seagrass
Best for Snorkel, Topside
Year-round
JanFebMarAprMayJunJulAugSepOctNovDec
NPS describes Maho and Francis Bay as feeding habitat where green turtles are often observed, but does not establish a reliable exact month-by-month encounter peak.
Hawksbill nesting and protection season
Best for Topside, Snorkel
Aug to Nov
JanFebMarAprMayJunJulAugSepOctNovDec
Park conservation records describe a late-summer/autumn hawksbill nesting focus.

Always true for this destination

Storm Disruptions.
Surface chop can add a little more texture on exposed entries.
The forecast and port/park alerts on the exact day outweigh an average monthly ranking.

Seasonal cautions

Dec to Mar: NPS warns that winter northern swell can impair north-coast sea entry, even in the drier travel season.
Jun to Nov: June 1 to November 30 is the official Atlantic hurricane season; conditions and transport can change at short notice.

Built from climate references, access rules, and destination operators. Wildlife timing and route flexibility can shift year to year.

Scope

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Aug

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Dec

Overall