Port Antonio in September: Weather, Rain Days, Sea Temperature and Crowds

PORT ANTONIO · SEPTEMBER · 18.18° N

You have already picked Port Antonio, so the open question is the date. September brings afternoons at an 85.1°F average high, a sea near 88°F at its daily peak, and measurable rain on roughly every other day at the wet north-eastern tip of Jamaica. For a swimmer who does not mind a shower, those are good numbers. For a hiker on a tight schedule, they are a reason to keep the plan loose.

The town is small enough for two or three nights (est.): the Titchfield Peninsula, where the English first settled the area, Folly Point Lighthouse from 1888, and the Blue and John Crow Mountains rising behind the harbor. Before you book the flight, our guides to flights from the US and airport transfers cover the travel end of the trip.

On this page

• Port Antonio weather in September85.1°F highs, 6.14 inches and 14.5 rain days
• Can you swim in September?An 87.9°F sea at its daily peak
• Crowds, booking and lodging taxLow season and refundable rates
• Things to do in SeptemberTitchfield Peninsula, Folly Point and Moore Town
• A two-day Port Antonio itineraryTwo days that end at the 6:08 pm sunset
• September vs August and OctoberHow the three months compare on rain and sea
• Is September a good time to go?Who should go, and who should wait for another month

Everything below turns on the date. The town’s beaches, hotels and year-round sights live in our Port Antonio guide, the island-wide calendar in the best time to visit Jamaica, and the storm recovery picture in Jamaica after Hurricane Melissa.

Port Antonio weather in September: average highs, lows and rain days

Our normals come from Open-Meteo’s ECMWF ERA5 reanalysis, averaged over 1991-2020 for the grid cell at 18.18° N over Port Antonio. A weather model reconstructs that square of map, and no station thermometer stands behind it, so every figure here describes the cell. It sets September at an 85.1°F average high, a 77.1°F low and 6.14 inches of rain. The cell sits on the wet north-eastern end of Jamaica, the island’s rainiest corner, so these numbers do not carry over to Montego Bay or Negril.

An average September logs 14.5 days with at least 0.10 inch of rain, roughly one day in two. Only 0.6 days reach an inch or more, so about three Septembers in five see one proper downpour, and the other wet days stay below that mark. In practice we put the beach and the walking in the morning and keep a covered fallback, a museum-free veranda lunch or a church interior, for the later hours.

Between the 85.1°F high and the 77.1°F low sits a gap of just 8.0°F, and nights never cool enough to need a sweater. Pack light cotton or linen, a packable rain shell, sandals that tolerate a wet street and a spare dry shirt for the mountains. Our Jamaica packing list has the full kit.

On September 15 Port Antonio gets about 12 hours 16 minutes of daylight, with sunrise at 5:52 am and sunset at 6:08 pm local time. Anything on foot, the lighthouse at Folly Point included, should end by early evening, and a dawn swim can start before six.

Can you swim in Port Antonio in September? Sea temperature

Yes. The Open-Meteo Marine API puts the sea surface off Port Antonio at 87.9°F in September, averaged over 2015-2024. That figure is the mean of daily maxima, the warmest reading of each day, so a 24-hour average would come out a shade cooler. Other sea tables may print a lower number for the same water, and both can be right.

At close to 88°F, the water feels warm from the first step, with no gasp at waist level. You can stay in for a long swim or a snorkel without a wetsuit. A swim at 6 am, before the sun climbs, is the coolest the water gets in a September day.

We could not read a wind or swell series for Port Antonio in September, so we give no wave height or wind speed. Check the local marine forecast on the morning you swim, and follow any flag or advice from hotel staff on the day. Our hurricane season guide explains how to read a tropical outlook.

How busy is Port Antonio in September? Crowds and prices

On the calendar, September falls in Jamaica’s low season and inside the Atlantic hurricane season. We found no occupancy series and no monthly room rates for Port Antonio, so we rank no month as the cheapest of the year. Our Jamaica trip cost guide sets out daily budgets for the island.

We found no booking-lead data for Port Antonio either, so we name no number of weeks. What September changes is the kind of rate to take: a refundable room and a changeable flight, since a tropical system can move a week of vacation. Buy travel insurance at the same time as the flight.

We could not verify Jamaica’s lodging tax rate, so we give no percentage. Before paying a deposit, ask the property in writing whether its quoted nightly price includes tax and service.

The one line where paying more alters a September trip is flexibility. A free-cancellation rate usually costs more at booking than a prepaid one, and it is the rate that lets you shift dates if the tropics turn active. Spend there before upgrading the room.

Things to do in Port Antonio in September

September has the warmest sea of the late-summer months at 87.9°F, plus 12 hours 16 minutes of light on the 15th. That leaves room for a dawn swim and a heritage walk before any rain moves in, with the mountains saved for a clear morning.

On the Titchfield Peninsula, the oldest settlement of Port Antonio, stand Fort George and DeMontevin Lodge, an eclectic Victorian building. In town, the Court House went up in 1895. Folly Point Lighthouse dates from 1888. West of town, Orange Bay Railway Station shows Jamaica Georgian features, and Seaman’s Valley holds a great-house ruin and the area’s first European cemetery. Inland, Moore Town, whose Maroon heritage UNESCO listed in 2008, borders the Blue and John Crow Mountains: 26,251.6 hectares from about 2,790 to 7,400 feet (850 to 2,256 m). We could not read opening hours or admission fees for any of these sites, or a raft rate on the Rio Grande.

The stonework of the 1888 lighthouse and the 1895 Court House looks the same in any month. September changes the air around them: 14.5 rain days against 12.9 in August, and wetter trails on the mountain slopes. Walk the peninsula early and treat a mountain day as weather-dependent.

We could not read an admission fee for any site in Port Antonio, so we cannot promise that any of them is free. The facades of DeMontevin Lodge and the Court House face public streets, and a walk past them costs nothing.

Port Antonio in September: a two-day itinerary

Day one. Swim at 6 am, a few minutes after the 5:52 am sunrise. By 8 am, walk the Titchfield Peninsula past Fort George and DeMontevin Lodge, then the 1895 Court House in town. Around midday, when the high nears 85.1°F, take lunch under cover and rest. At 4 pm head out to Folly Point Lighthouse and be back for dinner before the 6:08 pm sunset.

Day two. Go inland early toward Moore Town and the edge of the Blue and John Crow Mountains, ideally with a local guide. With rain on 14.5 days in an average September, keep a swap ready: if the sky turns, stay near the coast at Orange Bay Railway Station and Seaman’s Valley, or step into Portland Parish Church, Christ Church, after calling ahead, since we could not verify its hours. Our getting-around guide covers drivers and routes.

Port Antonio in September vs August and October

From the same ERA5 cell and period, air temperatures barely move from August to September, down 0.3°F on both the high and the low. Rain climbs from 5.20 to 6.14 inches and from 12.9 to 14.5 wet days. October drops the high to 83.8°F and pushes rain to 7.19 inches over 17.8 days. The Marine API sea figures peak in September at 87.9°F, against 87.1°F in August and 87.4°F in October.

Moving four weeks earlier to August buys 1.6 fewer rain days and 0.94 inch less rain, at the cost of water 0.8°F cooler. Moving four weeks later to October takes 1.3°F off the afternoon high, but adds 3.3 wet days and brings the sea down 0.5°F.

Is September a good time to visit Port Antonio?

Yes for swimmers, couples and heritage walkers who can shift a plan by a day and book refundable. Less so for travelers set on long mountain hikes on fixed dates, or anyone who wants a firm guarantee of dry weather during hurricane season.

If dry days matter most, pick August: 12.9 rain days and 5.20 inches, with highs of 85.4°F. For a Jamaica trip built around drier weather overall, our month-by-month verdict covers the rest of the island.

Of August, September and October, September alone gives Port Antonio a sea of 87.9°F at its daily peak.

The last word

Book the refundable room, put the swim at dawn and the walk before lunch, and let the rain decide which afternoon goes to the mountains. Then find Portland Parish Church, Christ Church, whose land was indentured on 3 September 1836, and stand outside it in the month its story began.

Sources & data for this guide

• Air normals for August, September and October, 1991-2020 · Open-Meteo / ECMWF ERA5 reanalysis, grid cell 18.1789 N, -76.4522 · a model reconstruction, not a station reading · checked Sep 24, 2026
• Rain days at 0.10 in and 1 in · same ERA5 cell and period · checked Sep 24, 2026
• Sea surface temperature, mean of daily maxima 2015-2024 · Open-Meteo Marine API · checked Sep 24, 2026
• Daylight, sunrise and sunset on September 15 · sunrise-sunset.org, converted from UTC to local time · checked Sep 24, 2026
• Titchfield Peninsula, Court House, Folly Point, DeMontevin Lodge, Christ Church, Maroon towns, Orange Bay and Seaman’s Valley · Jamaica National Heritage Trust, Portland Heritage Sites · checked Sep 24, 2026
• Blue and John Crow Mountains and Moore Town Maroon heritage · UNESCO World Heritage Centre, property 1356 · checked Sep 24, 2026
• We could not read opening hours or admission fees for any Port Antonio site, a Rio Grande raft rate, a lodging-tax rate, occupancy data, or a wind and swell series · confirm with operators when you book.

To plan your stay

• Port Antonio: When to Go, When to Swim and Which Month to Avoid
• Port Antonio in August: Weather, Rain Days, Sea Temperature and Crowds
• Port Antonio in October: Weather, Sea Temperature, Crowds and a Two-Day Plan
• Port Antonio in July: Weather, Sea Temperature, Rain Days and Things to Do

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• Blue Mountains, Jamaica: Peak Hikes, Coffee Farms and the Two Ways In
• Kingston, Jamaica: The Bob Marley Museum, Devon House and Trench Town
• Dunns River Falls: Tickets, Timing and How to Beat the Cruise Crowds