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When To Go · Destination Guide

Key Largo

America's first undersea park meets easy reef days and legendary wrecks

Updated Dec 13, 2025 • 12 sources

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When To Go

Season planner for Key Largo

Key Largo sits in a tropical-maritime climate with a dry season (roughly December to April) and a wet season (June to October). Dry-season weeks are comfortable topside and popular with travelers, while wet-season months often bring warmer water and calmer seas between thunderstorms. Average South Florida sea temperatures run about 21°C to 30°C through the year. Plan around cold fronts in winter and hurricane-season risk in late summer and early fall.

At A Glance Heatmap

ActivityJanFebMarAprMayJunJulAugSepOctNovDec
Overall
Scuba
Freedive
Snorkel
Topside

Activity Drilldowns

PrimeShoulderPlan Carefully
Overall
December to April·Crowd:High In Winter, Moderate In Shoulder Months·Cost:Premium In Winter, Moderate In Summer
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Ideal: Dry season with lower humidity and more reliable sunshine. Water often feels like 22°C to 26°C.

Plan Carefully: Wet season heat, afternoon thunderstorms, and hurricane-season risk. Keep plans flexible and watch forecasts.

Hurricane season officially runs June 1 to November 30, with peak activity typically midAugust to midOctober.

Scuba
May to August·Crowd:Moderate (Peaks During Winter Holidays And Spring Break)·Cost:Moderate To Premium
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Ideal: Warm water 27°C to 30°C and often calmer seas for long reef dives and easier boat crossings.

Plan Carefully: Cooler water 21°C to 24°C and periodic cold fronts. Wind can exceed 25.0 kph and cancel boats.

Wreck dives are the first to be canceled when seas build.

Freedive
May to September·Crowd:Moderate·Cost:Moderate To Premium
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Ideal: Warm water and generally smoother surface conditions between storms. Better comfort for long breath-hold sessions.

Plan Carefully: Cooler water and frequent wind events. Surface chop can make buddy tracking difficult.

Freedivers should prioritize surface safety: float, flag, buddy contact, and conservative limits.

Snorkel
April to August·Crowd:High In Spring Break And Summer Weekends·Cost:Moderate To Premium
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Ideal: Warm water and the best chance of flat seas and clear surface viewing. Visibility can reach 15 m to 25 m after calm weather.

Plan Carefully: Cooler water and more wind-driven chop. Snorkeling can still be good on calm days, but cancellations are more common.

If conditions are choppy, switch plans to a glassbottom boat, visitor centers, or mangrove paddling on the bay side.

Topside
December to April·Crowd:High In Winter·Cost:Premium In Winter, Moderate In Summer
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Ideal: Comfortable air temperatures and lower humidity for hiking and paddling. Best overall road-trip weather.

Plan Carefully: Hot, humid, and thunderstorm-prone. Hurricane-season risk is highest in late summer and early fall.

Start outdoor activities early, then save afternoons for shade, naps, or bayside restaurants.

Seasonal Callouts Timeline

  • REEF Florida Keys Lionfish Derby and Arts Festival

    JanJan
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    OctOct
    NovNov
    DecDec

    Late April often brings a community lionfish removal competition that culminates at the REEF campus in Key Largo with a public festival, conservation booths, and awards.

  • Spiny lobster mini-season

    JanJan
    FebFeb
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    MayMay
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    SepSep
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    NovNov
    DecDec

    Florida's spiny lobster sport season is the last consecutive Wednesday and Thursday of July each year. Monroe County has special rules and protected areas and night diving is prohibited during the sport season.

  • Regular spiny lobster season

    JanJan
    FebFeb
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    AprApr
    MayMay
    JunJun
    JulJul
    AugAug
    SepSep
    OctOct
    NovNov
    DecDec

    The regular Florida spiny lobster season runs from early August through March. A saltwater license and lobster permit are required, and harvest is prohibited in no-take zones and certain protected areas.

  • Sea turtle nesting and hatchlings

    JanJan
    FebFeb
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    AprApr
    MayMay
    JunJun
    JulJul
    AugAug
    SepSep
    OctOct
    NovNov
    DecDec

    Sea turtle nesting season in South Florida generally spans late spring through early fall. Give nesting beaches space at night and keep lights low near the shoreline.

  • Hot-water coral stress and bleaching risk

    JanJan
    FebFeb
    MarMar
    AprApr
    MayMay
    JunJun
    JulJul
    AugAug
    SepSep
    OctOct
    NovNov
    DecDec

    Mid-summer sea temperatures can rise into the upper end of the 21°C to 30°C range, increasing coral stress. Practice extra no-touch discipline and follow any local advisories on reef closures or best practices.