When to dive
Diving in September
Ranked by our documented month ratings — water, visibility and what each place is actually like in September. Destinations without verified monthly data are listed separately rather than guessed at.
| Destination | Rating | Water | Visibility | What September is like there |
|---|---|---|---|---|
| Cairns & the Ribbon ReefsAustralia | 5/5 | 23–26 °C / 73–79 °F | 20–35 m | Winds ease; some of the best visibility of the year |
| Sharm El Sheikh & Ras MohammedEgypt | 5/5 | 27–29 °C / 81–84 °F | 20–30 m | Warm sea and thinner crowds - a superb balance. |
| KomodoIndonesia | 5/5 | 21–28 °C / 70–82 °F | 15–30 m | Superb diving continues with slightly thinner crowds. |
| BonaireBonaire | 5/5 | 28–30 °C / 82–86 °F | 20–30 m | Warmest, calmest water of the year. |
| Bali & Nusa PenidaIndonesia | 5/5 | 22–28 °C / 72–82 °F | 15–30 m | Often the best all-around month: dry, clear, and full of life. |
| Galápagos IslandsEcuador | 5/5 | 17–22 °C / 63–72 °F | 10–20 m | |
| Kona, HawaiʻiUnited States | 5/5 | 26–28 °C / 79–82 °F | 25–40 m | Often the year's best conditions. |
| DahabEgypt | 5/5 | 27–29 °C / 81–84 °F | 15–30 m | Warm sea, thinning crowds - a local favorite. |
| Lembeh StraitIndonesia | 5/5 | 25–28 °C / 77–82 °F | 10–20 m | Cool, rich water and heavy juvenile activity. |
| Sea of Cortez & Cabo PulmoMexico | 5/5 | 28–30 °C / 82–86 °F | 20–30 m | Prime conditions; watch tropical storm forecasts. |
| Marsa Alam & the Deep SouthEgypt | 5/5 | 28–30 °C / 82–86 °F | 20–30 m | Warm sea and long settled spells. |
| Taveuni & Rainbow ReefFiji | 5/5 | 25–27 °C / 77–81 °F | 20–40 m | Excellent conditions, fewer crowds. |
| Baa Atoll & Hanifaru BayMaldives | 5/5 | 27–29 °C / 81–84 °F | 10–20 m | Peak continues; whale sharks join some events. |
| Hurghada & El GounaEgypt | 5/5 | 27–29 °C / 81–84 °F | 15–30 m | Warm sea and settling weather. |
| Brothers, Daedalus & St John'sEgypt | 5/5 | 28–30 °C / 82–86 °F | 20–40 m | Transition month - a bit of everything. |
| The AzoresPortugal | 5/5 | 22–24 °C / 72–75 °F | 20–40 m | Warmest water; blue sharks and mobulas both reliable. |
| Malta & GozoMalta | 5/5 | 23–26 °C / 73–79 °F | 25–40 m | |
| Cocos IslandCosta Rica | 5/5 | 24–28 °C / 75–82 °F | 12–25 m | Peak season for big animals and whale shark chances. |
| Aliwal Shoal & UmkomaasSouth Africa | 5/5 | 19–23 °C / 66–73 °F | 10–25 m | Raggies still thick; humpbacks passing offshore. |
| AqabaJordan | 5/5 | 26–28 °C / 79–82 °F | 15–30 m | Warm sea and cooling evenings. |
| Coral Sea & Osprey ReefAustralia | 5/5 | 24–26 °C / 75–79 °F | 30–60 m | Winds drop; prime expedition month |
| Townsville & the YongalaAustralia | 5/5 | 23–25 °C / 73–77 °F | 15–30 m | The best visibility window begins |
| Daymaniyat IslandsOman | 5/5 | 28–31 °C / 82–88 °F | 10–25 m | Whale shark season opens; warm and lively. |
| Zanzibar & MnembaTanzania | 5/5 | 25–27 °C / 77–81 °F | 15–30 m | Excellent diving with lighter crowds. |
| OʻahuUnited States | 5/5 | 26–28 °C / 79–82 °F | 18–35 m | Often the calmest stretch. |
| Fernando de NoronhaBrazil | 5/5 | 26–28 °C / 79–82 °F | 25–40 m | |
| California Channel IslandsUnited States | 5/5 | 17–21 °C / 63–70 °F | 15–25 m | The classic month - warm, clear, calm. |
| WakatobiIndonesia | 5/5 | 26–29 °C / 79–84 °F | 20–40 m | Consistently superb; light winds. |
| Maui & MolokiniUnited States | 5/5 | 26–28 °C / 79–82 °F | 30–45 m | Often the calmest month. |
| Bunaken & ManadoIndonesia | 5/5 | 26–29 °C / 79–84 °F | 20–35 m | Superb diving continues with fewer visitors. |
| CuraçaoCuraçao | 5/5 | 28–30 °C / 82–86 °F | 18–30 m | |
| Scapa FlowUnited Kingdom | 5/5 | 12–14 °C / 54–57 °F | 6–12 m | Warmest water of the year and settled spells; a favorite month. |
| Larnaca & the ZenobiaCyprus | 5/5 | 25–27 °C / 77–81 °F | 20–35 m | |
| Costa Rica Pacific CoastCosta Rica | 5/5 | 26–29 °C / 79–84 °F | 12–20 m | |
| VavaʻuTonga | 5/5 | 23–25 °C / 73–77 °F | 20–40 m | Peak continues; calves growing bold. |
| Espiritu SantoVanuatu | 5/5 | 24–26 °C / 75–79 °F | 15–30 m | Reliable trade-wind weather. |
| Beqa Lagoon & Pacific HarbourFiji | 5/5 | 25–27 °C / 77–81 °F | 12–28 m | Late dry season, reliable feeds. |
| Canary IslandsSpain | 5/5 | 23–25 °C / 73–77 °F | 20–30 m | Warmest water and typically the best visibility. |
| Nosy BeMadagascar | 5/5 | 25–28 °C / 77–82 °F | 12–25 m | Humpbacks linger; first whale sharks. |
| MadeiraPortugal | 5/5 | 23–25 °C / 73–77 °F | 15–30 m | Warmest sea of the year. |
| AlorIndonesia | 5/5 | 21–27 °C / 70–81 °F | 15–30 m | A favorite month: seas calm while the water stays rich. |
| Medes IslandsSpain | 5/5 | 21–24 °C / 70–75 °F | 12–30 m | Barracuda schools at their densest. |
| Izu PeninsulaJapan | 5/5 | 23–26 °C / 73–79 °F | 8–18 m | Autumn calm; peak conditions |
| Riviera Maya & the CenotesMexico | 4/5 | 24–26 °C / 75–79 °F | 25–80 m | Rainy season can tint open cenotes. |
| Sipadan & MabulMalaysia | 4/5 | 27–30 °C / 81–86 °F | 15–30 m | Still strong as the calm season winds down. |
| Koh TaoThailand | 4/5 | 28–30 °C / 82–86 °F | 10–25 m | Often underrated; whale sharks reappear. |
| Silfra & IcelandIceland | 4/5 | 2–4 °C / 36–39 °F | 70–100 m | |
| FakaravaFrench Polynesia | 4/5 | 25–27 °C / 77–81 °F | 25–40 m | Reliable trades. |
| Florida KeysUnited States | 4/5 | 28–30 °C / 82–86 °F | 15–30 m | Peak hurricane risk - build flexibility into plans. |
| RangiroaFrench Polynesia | 4/5 | 25–27 °C / 77–81 °F | 25–40 m | Winds easing. |
| Ningaloo ReefAustralia | 4/5 | 21–23 °C / 70–73 °F | 10–20 m | Whales stream south in cool clear water |
| UtilaHonduras | 4/5 | 28–30 °C / 82–86 °F | 15–30 m | Sightings continue; watch the tropics. |
| British ColumbiaCanada | 4/5 | 11–15 °C / 52–59 °F | 8–18 m | |
| Mafia IslandTanzania | 4/5 | 25–27 °C / 77–81 °F | 15–25 m | Winds ease; conditions improve. |
| Sodwana BaySouth Africa | 4/5 | 21–24 °C / 70–75 °F | 10–25 m | Spring; whales southbound with calves. |
| MauritiusMauritius | 4/5 | 23–26 °C / 73–79 °F | 10–25 m | Trades ease; whales still passing. |
| Banda Sea & AmbonIndonesia | 4/5 | 26–29 °C / 79–84 °F | 20–40 m | Main season opens; hammerhead encounters pick up. |
| Tofo BeachMozambique | 4/5 | 23–26 °C / 73–79 °F | 10–25 m | Mothers and calves close inshore. |
| North Carolina Outer BanksUnited States | 4/5 | 24–27 °C / 75–81 °F | 15–30 m | Prime diving between tropical systems - stay flexible. |
| BermudaBermuda | 4/5 | 26–28 °C / 79–82 °F | 20–40 m | Warm water but hurricane-swell watch. |
| Green IslandTaiwan | 4/5 | 27–29 °C / 81–84 °F | 20–40 m | Fine diving between weather systems |
| CoibaPanama | 4/5 | 25–29 °C / 77–84 °F | 8–18 m | Whale song on most dives; rain squalls between boats. |
| North & South Malé AtollsMaldives | 3/5 | 27–29 °C / 81–84 °F | 10–20 m | Wet spells persist; mantas still working the east side. |
| PalauPalau | 3/5 | 27–30 °C / 81–86 °F | 12–30 m | Late monsoon; unsettled spells between good windows. |
| CozumelMexico | 3/5 | 28–30 °C / 82–86 °F | 15–35 m | Peak hurricane risk; quietest season. |
| Raja AmpatIndonesia | 3/5 | 26–29 °C / 79–84 °F | 10–20 m | Trades ease late in the month; operators begin returning. |
| AnilaoPhilippines | 3/5 | 27–29 °C / 81–84 °F | 8–20 m | Late monsoon; conditions begin to steady. |
| Isla Mujeres & CancúnMexico | 3/5 | 28–30 °C / 82–86 °F | 10–25 m | Sharks disperse; storm risk peaks. |
| Chuuk (Truk) LagoonFederated States of Micronesia | 3/5 | 28–30 °C / 82–86 °F | 10–25 m | Unsettled spells continue. |
| RoatánHonduras | 3/5 | 28–30 °C / 82–86 °F | 15–30 m | Storm season peaks regionally. |
| Ari AtollMaldives | 3/5 | 27–29 °C / 81–84 °F | 10–20 m | Wettest stretch of the monsoon. |
| Belize Barrier ReefBelize | 3/5 | 28–30 °C / 82–86 °F | 10–25 m | Peak storm season; unsettled. |
| MalapascuaPhilippines | 3/5 | 28–30 °C / 82–86 °F | 10–20 m | Rainy but rarely unworkable. |
| Grand CaymanCayman Islands | 3/5 | 29–30 °C / 84–86 °F | 15–30 m | Peak hurricane risk; quiet island. |
| CoronPhilippines | 3/5 | 28–30 °C / 82–86 °F | 5–12 m | Late monsoon; watch typhoon tracks. |
| Poor Knights IslandsNew Zealand | 3/5 | 14–16 °C / 57–61 °F | 8–20 m | Spring bloom starts to haze the water |
| MoalboalPhilippines | 3/5 | 28–30 °C / 82–86 °F | 8–20 m | Late-monsoon pattern; runoff can dim the shallows. |
| Dumaguete, Dauin & Apo IslandPhilippines | 3/5 | 27–29 °C / 81–84 °F | 10–20 m | Late wet season; visibility varies with runoff. |
| Nassau & New ProvidenceThe Bahamas | 3/5 | 28–30 °C / 82–86 °F | 15–30 m | Peak hurricane season; watch forecasts. |
| GrenadaGrenada | 3/5 | 28–30 °C / 82–86 °F | 12–25 m | Peak of the Atlantic storm season. |
| Little CaymanCayman Islands | 3/5 | 29–30 °C / 84–86 °F | 15–30 m | Peak storm risk; some resorts close. |
| YapFederated States of Micronesia | 3/5 | 28–30 °C / 82–86 °F | 8–25 m | Wetter; storm fringe possible. |
| SeychellesSeychelles | 3/5 | 25–28 °C / 77–82 °F | 10–20 m | Winds begin to ease late month. |
| Okinawa & the Kerama IslandsJapan | 3/5 | 27–29 °C / 81–84 °F | 15–35 m | Swell from passing storms |
| South AustraliaAustralia | 3/5 | 13–15 °C / 55–59 °F | 4–12 m | Spring wind and plankton |
| Port Sudan & SanganebSudan | 3/5 | 29–31 °C / 84–88 °F | 15–40 m | Mantas peak as the heat eases slightly. |
| Arctic NorwayNorway | 3/5 | 9–12 °C / 48–54 °F | 8–20 m | |
| Musandam PeninsulaOman | 3/5 | 29–32 °C / 84–90 °F | 8–18 m | Big-animal season continues; visibility modest. |
| YonaguniJapan | 3/5 | 27–29 °C / 81–84 °F | 20–40 m | Typhoon swell risk |
| Tiger Beach & Grand BahamaThe Bahamas | 2/5 | 28–30 °C / 82–86 °F | 15–30 m | Statistical peak of hurricane season. |
| British Virgin IslandsBritish Virgin Islands | 2/5 | 28–30 °C / 82–86 °F | 15–25 m | Peak hurricane season; many boats haul out. |
| DominicaDominica | 2/5 | 28–30 °C / 82–86 °F | 10–25 m | Peak storm season; heavy rain can cloud the shallows. |
| Jardines de la ReinaCuba | 2/5 | 29–31 °C / 84–88 °F | 15–30 m | Peak hurricane months; few departures. |
| Saint LuciaSaint Lucia | 2/5 | 28–30 °C / 82–86 °F | 10–25 m | Peak hurricane season; rain can cloud nearshore water. |
| Turks and CaicosTurks and Caicos Islands | 2/5 | 28–30 °C / 82–86 °F | 15–30 m | Peak hurricane risk; some operations pause. |
| Similan Islands & Richelieu RockThailand | 1/5 | — | — | Monsoon closure; no access. |
| Tubbataha ReefsPhilippines | 1/5 | — | — | Closed to dive traffic through the wet season. |
| The Sardine Run (Wild Coast)South Africa | 1/5 | 18–22 °C / 64–72 °F | 5–15 m | No run; humpbacks still migrating. |
| Mergui ArchipelagoMyanmar | 1/5 | — | — | No access; seas remain rough. |
Wildlife calendar
In the water in September
Blue Shark
e.g. The Azores
Bottlenose Dolphin
e.g. The Azores
Bull Shark
e.g. Costa Rica Pacific Coast
California Sea Lion
e.g. Sea of Cortez & Cabo Pulmo
Atlantic Goliath Grouper
e.g. Florida Keys
Humpback Whale
e.g. Ningaloo Reef
Mobula (Devil) Ray
e.g. The Azores
Mola Mola (Ocean Sunfish)
e.g. Bali & Nusa Penida
Olive Ridley Turtle
e.g. Costa Rica Pacific Coast
Reef Manta Ray
e.g. Baa Atoll & Hanifaru Bay
Sand Tiger (Ragged-Tooth) Shark
e.g. Aliwal Shoal & Umkomaas
Scalloped Hammerhead
e.g. Cocos Island
Make it a trip
The planner crosses this month with your level and interests, and shows its reasons for every match.
Plan a September trip