# Weather risk for a yacht charter, month by month

> Hurricanes, meltemi, bora and jugo, monsoon and wet season: when each hits 10 charter areas, with NOAA storm counts and NASA wind data. Sourced, dated.

URL: https://catamaranindex.com/weather-risk/
Last updated: 2026-10-29
Author: Catamaran Index editorial team

The main seasonal weather risks for a yacht charter are hurricanes in the BVI, the Bahamas and Belize (1 June–30 November, most activity mid-August to mid-October, NOAA), the summer meltemi in the Aegean (most frequent mid-July to mid-August), the bora and jugo in Croatia's colder months, the southwest monsoon on Thailand's Andaman coast (mid-May to mid-October) and French Polynesia's wet season (November to April). The calendar below marks each by month from official or peer-reviewed sources, and our counts of storm passes (NOAA HURDAT2) and strong-wind days (NASA POWER) show how often each one actually hit our reference points.

*Checked 29 Oct 2026. Official dates are quoted; counts are our calculation from NOAA and NASA data ([how we count](#method)); facts are labelled official, secondary or not verified ([labels](#labels)).*

## Weather-risk calendar

| Destination | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Source | Boats |
|---|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|---|---|
| [Croatia](https://catamaranindex.com/weather-risk/croatia/) | – | – | – | – | – | – | – | – | – | – | – | – | DHMZ (no months) | [SamBoat](https://catamaranindex.com/go/samboat?dest=croatia&pos=weatherrisk-row) |
| [Greece](https://catamaranindex.com/weather-risk/greece/) | – | – | – | – | – | – | Meltemi peak | Meltemi peak | – | – | – | – | Peer-reviewed study | [SamBoat](https://catamaranindex.com/go/samboat?dest=greece&pos=weatherrisk-row) |
| [BVI](https://catamaranindex.com/weather-risk/bvi/) | – | – | – | – | – | Hurricane season | Hurricane season | Peak | Peak | Peak | Hurricane season | – | NOAA NHC | [SamBoat](https://catamaranindex.com/go/samboat?dest=bvi&pos=weatherrisk-row) |
| [Bahamas](https://catamaranindex.com/weather-risk/bahamas/) | – | – | – | – | – | Hurricane season | Hurricane season | Peak | Peak | Peak | Hurricane season | – | NOAA NHC | [SamBoat](https://catamaranindex.com/go/samboat?dest=bahamas&pos=weatherrisk-row) |
| [Turkey](https://catamaranindex.com/turkey/#weather) | – | – | – | – | – | – | – | – | – | – | – | – | None verified | [SamBoat](https://catamaranindex.com/go/samboat?dest=turkey&pos=weatherrisk-row) |
| [Italy](https://catamaranindex.com/italy/#weather) | – | – | – | – | – | – | – | – | – | – | – | – | None verified | [SamBoat](https://catamaranindex.com/go/samboat?dest=italy&pos=weatherrisk-row) |
| [Balearic Islands](https://catamaranindex.com/balearics/#weather) | – | – | – | – | – | – | – | – | – | – | – | – | None verified | [SamBoat](https://catamaranindex.com/go/samboat?dest=mallorca&pos=weatherrisk-row) |
| [Thailand](https://catamaranindex.com/weather-risk/thailand/) | NE monsoon | NE monsoon | – | – | SW monsoon | SW monsoon | SW monsoon | SW monsoon | SW monsoon | SW → NE monsoon | NE monsoon | NE monsoon | Land Development Dept. | [SamBoat](https://catamaranindex.com/go/samboat?dest=thailand&pos=weatherrisk-row) |
| [French Polynesia](https://catamaranindex.com/weather-risk/french-polynesia/) | Wet season | Wet season | Wet season | Wet season | – | – | – | – | – | – | Wet season | Wet season | Météo-France | [SamBoat](https://catamaranindex.com/go/samboat?dest=french-polynesia&pos=weatherrisk-row) |
| [Belize](https://catamaranindex.com/weather-risk/belize/) | – | – | – | – | – | Hurricane season · rainy | Hurricane season · rainy | Peak · rainy | Peak · rainy | Peak · rainy | Hurricane season · rainy | – | NOAA NHC; NMS Belize | [SamBoat](https://catamaranindex.com/go/samboat?dest=belize&pos=weatherrisk-row) |

A month is marked if any part of it falls in the source's window (our mapping). "Mid-May" and similar are the source's words. Croatia shows "–": DHMZ says the bora and jugo are more frequent and stronger in the cold part of the year and names no months. The three destinations with "–" in every month have no named seasonal hazard in our sources.

## Storm passes in the Caribbean and Belize

Years out of 30 (1991–2020) in which at least one tropical storm or hurricane passed within 100 nm of our reference point in that month (our count from NOAA's HURDAT2, [NOAA National Hurricane Center](https://www.nhc.noaa.gov/data/#hurdat), checked 29 Oct 2026).

| Month | BVI | Bahamas | Belize |
|---|---:|---:|---:|
| [January](https://catamaranindex.com/where-to-sail/january/) | 0 | 0 | 0 |
| [February](https://catamaranindex.com/where-to-sail/february/) | 0 | 0 | 0 |
| [March](https://catamaranindex.com/where-to-sail/march/) | 0 | 0 | 0 |
| [April](https://catamaranindex.com/where-to-sail/april/) | 0 | 0 | 0 |
| [May](https://catamaranindex.com/where-to-sail/may/) | 0 | 0 | 1 |
| [June](https://catamaranindex.com/where-to-sail/june/) | 0 | 0 | 1 |
| [July](https://catamaranindex.com/where-to-sail/july/) | 1 | 3 | 0 |
| [August](https://catamaranindex.com/where-to-sail/august/) | 9 | 6 | 2 |
| [September](https://catamaranindex.com/where-to-sail/september/) | 6 | 4 | 3 |
| [October](https://catamaranindex.com/where-to-sail/october/) | 4 | 2 | 4 |
| [November](https://catamaranindex.com/where-to-sail/november/) | 1 | 3 | 0 |
| [December](https://catamaranindex.com/where-to-sail/december/) | 0 | 0 | 0 |

1991–2020 is NOAA's 30-year climate period. The 100 nm radius is our choice, and a pass within it does not mean storm-force winds at the anchorage. Per destination: [BVI](https://catamaranindex.com/weather-risk/bvi/), [Bahamas](https://catamaranindex.com/weather-risk/bahamas/), [Belize](https://catamaranindex.com/weather-risk/belize/).

## Strong-wind days by month

Days per month whose highest hourly mean wind reached force 6 (22 kn or more), mean over 2016–2025 (our calculation from [NASA POWER](https://power.larc.nasa.gov/docs/services/api/temporal/daily/), checked 29 Oct 2026). **Bold** = the point's highest month.

| Point | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|
| BVI (Road Town) | 1.1 | 0.5 | 0.2 | 0.3 | 0.0 | 0.1 | 0.4 | 0.7 | **1.6** | 0.2 | 0.2 | 0.5 |
| Bahamas (Marsh Harbour) | **3.9** | 2.6 | 2.6 | 0.6 | 0.8 | 0.2 | 0.0 | 0.5 | 1.8 | 1.7 | 2.5 | 2.3 |
| Belize (Placencia) | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | **0.2** | 0.0 |
| Thailand (Ao Chalong) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| French Polynesia (Raiatea) | 0.9 | **1.5** | 0.3 | 0.0 | 0.2 | 0.3 | 0.6 | 0.8 | 0.6 | 0.4 | 0.6 | 0.9 |
| Croatia (Split) | 2.3 | 3.4 | 2.1 | 1.9 | 0.5 | 0.2 | 0.2 | 0.0 | 0.6 | 1.5 | **3.7** | 2.9 |
| Croatia (Dubrovnik) | 3.7 | 3.9 | 3.2 | 0.9 | 0.2 | 0.4 | 0.3 | 0.0 | 0.5 | 1.6 | 4.1 | **4.4** |
| Greece, Ionian (Lefkada) | 0.7 | 0.3 | 0.6 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | **0.8** | 0.2 |
| Greece, Cyclades (Syros) | **9.6** | 9.3 | 7.4 | 3.7 | 1.9 | 1.4 | 4.9 | 4.7 | 4.7 | 3.9 | 4.6 | 6.9 |
| Turkey (Göcek) | **1.3** | 0.7 | 0.8 | 0.2 | 0.2 | 0.2 | 0.0 | 0.0 | 0.1 | 0.0 | 0.3 | 0.4 |
| Italy (Portisco) | **6.0** | 3.4 | 4.1 | 2.9 | 1.9 | 0.7 | 1.2 | 1.4 | 1.6 | 2.7 | 3.9 | 4.7 |
| Balearics (Ibiza) | **6.5** | 3.1 | 5.3 | 2.8 | 1.0 | 0.2 | 0.7 | 0.4 | 1.2 | 2.2 | 5.9 | 5.5 |

Force 6 is a strong breeze, 22–27 kn on the Met Office scale ([Met Office](https://weather.metoffice.gov.uk/guides/coast-and-sea/beaufort-scale), checked 29 Oct 2026). These are grid-cell means, not gusts, and a point with only zeros (Thailand, and almost Belize) does not mean calm seas.

## Rain by month in the tropics

Mean monthly rainfall in mm, 2016–2025 (our calculation from NASA POWER's corrected precipitation, not a rain-gauge normal).

| Point | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|
| BVI (Road Town) | 27 | 27 | 22 | 36 | 51 | 45 | 55 | 70 | 81 | 106 | 99 | 32 |
| Bahamas (Marsh Harbour) | 54 | 29 | 43 | 53 | 100 | 109 | 75 | 77 | 127 | 102 | 56 | 48 |
| Belize (Placencia) | 180 | 86 | 92 | 48 | 137 | 268 | 215 | 228 | 247 | 303 | 352 | 189 |
| Thailand (Ao Chalong) | 104 | 52 | 71 | 150 | 318 | 266 | 283 | 326 | 360 | 345 | 308 | 214 |
| French Polynesia (Raiatea) | 188 | 163 | 106 | 117 | 79 | 83 | 50 | 48 | 48 | 84 | 123 | 210 |

## Destinations with no named seasonal hazard in our sources

- We have no official source naming a seasonal storm or wind hazard for Turkey; at our Göcek point, days reaching force 6 average 1.3 in January and 0.0 in July (our calculation from NASA POWER, 2016–2025). Monthly mean wind is on the [Turkey page](https://catamaranindex.com/turkey/#weather).
- We have no official source naming a seasonal storm or wind hazard for Italy; at our Portisco, Sardinia point, days reaching force 6 average 6.0 in January and 1.2 in July (our calculation from NASA POWER, 2016–2025). Monthly mean wind is on the [Italy page](https://catamaranindex.com/italy/#weather).
- We have no official source naming a seasonal storm or wind hazard for the Balearic Islands; at our Ibiza Town point, days reaching force 6 average 6.5 in January and 0.7 in July (our calculation from NASA POWER, 2016–2025). Monthly mean wind is on the [Balearic Islands page](https://catamaranindex.com/balearics/#weather).

## Cancellation, insurance and weather guarantees

Booking in a risk season? Read your charter contract's weather and hurricane clauses: what happens if a named storm or a port closure stops you sailing, and whether you get a refund, a credit or new dates. Some booking platforms and charter companies sell cancellation options or a "weather guarantee", and some travel insurance covers trip cancellation or cutting a trip short because of weather; check what triggers the cover. We have no insurance partner and do not recommend a product. See our [affiliate disclosure](https://catamaranindex.com/affiliate-disclosure/).

## Compare boats

**[See catamarans for rent on SamBoat](https://catamaranindex.com/go/samboat?dest=catamarans&pos=weatherrisk)**

Ask the operator about its weather and hurricane policy before you book; listings and prices on SamBoat are SamBoat's own. We may earn a commission if you book through our links, at no extra cost to you ([disclosure](https://catamaranindex.com/affiliate-disclosure/)).

## How we count

Storm passes: from NOAA's HURDAT2 best-track file (hurdat2-1851-2025-092326.txt) we take every tropical storm or hurricane (HURDAT2 status TS or HU) whose track starts in 1991–2020, NHC's 30-year climate period. We interpolate the track in a straight line every 60 minutes between fixes (not across gaps over 12 hours) and count a storm once, in the month it first came within 100 nm of our reference point. The 100 nm radius, the interpolation and the month rule are our choices. "Storm-years" are the years out of 30 with at least one pass in that month. Our calculation.

Strong-wind days: from NASA POWER's daily WS10M_MAX (the highest hourly mean 10 m wind of the day in one grid cell), converted to knots (1 m/s = 3600/1852 kn), we count the days per month at or above 17 kn (Beaufort force 5, fresh breeze) and 22 kn (force 6, strong breeze), the lower limits on the Met Office scale, as a mean per month over 2016–2025. Direction shares use the day's mean wind direction (WD10M) in 45° bins. Our calculation.

Rain: NASA POWER's monthly corrected precipitation (PRECTOTCORR, mm/day) times the days in each month, averaged over 2016–2025, whole millimetres. Our calculation, not a rain-gauge normal.

Calendar: a month is marked if any part of it falls in the source's window (our mapping). "Mid-July", "the cold part of the year" and similar are the source's words.

Constants: radius 100 nm, storms 1991–2020, interpolation every 60 minutes, HURDAT2 codes TS and HU (file hurdat2-1851-2025-092326.txt, updated 23 September 2026); strong-wind thresholds 17 kn (force 5) and 22 kn (force 6), years 2016–2025, 45° direction bins, NASA POWER API v2.10.1.

Weather data obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) Project, funded through the NASA Earth Science Division (pulled 29 Oct 2026) ([NASA POWER](https://power.larc.nasa.gov/docs/services/api/temporal/daily/), checked 29 Oct 2026). We changed the data: we counted days above thresholds, binned wind directions and summed daily rain into months (our calculation).

1. Storm passes are historical frequencies for 1991–2020 within 100 nm of one reference point (our choice of radius); they are not a forecast, and a pass within 100 nm does not mean storm-force winds at the anchorage.
2. Strong-wind days use NASA POWER's highest hourly mean wind of the day in a ½° × ⅝° grid cell (about 50 km across); real gusts and local winds (funnelling between islands, the bora at the foot of the mountains) are stronger than the cell shows.
3. Some grid cells include land (elevation from NASA POWER: 3 m at Road Town, Tortola, 0 m at Marsh Harbour, Abaco, 7 m at Placencia, 11 m at Ao Chalong, Phuket, 4 m at Raiatea, 212 m at Split, 144 m at Dubrovnik, 138 m at Lefkada, 21 m at Ermoupoli, Syros, 546 m at Göcek, 187 m at Portisco, Sardinia, 19 m at Ibiza Town), so their winds are lower than at sea.
4. Wind direction is the cell's daily mean direction; north-easterly days are our proxy for the bora and northerly days for the meltemi, not observed events.
5. Rainfall is NASA POWER's corrected precipitation for the cell, not a rain-gauge normal from the national weather service.
6. Official dates ("mid-July", "the cold part of the year") are quoted; our month mapping in the calendar is ours.

Data: [JSON](https://catamaranindex.com/api/weather-risk.json).

## What we could not verify

- Months of the bora and jugo season from DHMZ (it says "the cold part of the year" and gives no months).
- An official Greek page on the meltemi (the Hellenic National Meteorological Service site failed to load for us).
- A start and end date for the meltemi season from an official source.
- The BVI Department of Disaster Management's own season page (not opened).
- The Bahamas Department of Meteorology climate document (the PDF could not be read).
- No official source naming a seasonal wind or storm hazard for our Göcek reference point was opened.
- No official source naming a seasonal wind or storm hazard for our Sardinia (Portisco) reference point was opened.
- No official source naming a seasonal wind or storm hazard for our Ibiza reference point was opened.
- The Thai Meteorological Department climate page (it returned HTTP 500 to us).
- Phuket station rainfall normals from the Thai Meteorological Department.
- Official start and end dates of the cyclone season.
- Météo-France station normals for Raiatea.
- Belize hurricane counts for a stated period from the National Meteorological Service (its table does not say which years it covers).

## How to read the labels

- **[Peer-reviewed study, not a government source]**: a published scientific paper, used where we could open no official page; labelled secondary in our data.
- **[Secondary source]**: From a newspaper, NGO, guide or tour operator; not official.
- **[Not verified]**: We could not confirm it. We leave it open rather than guess.
- No label: Read in an official text: government, park authority, ministry or official tourism board.

Counts, shares, means and rainfall totals are our calculation, and say so; radii, thresholds and month mappings are our choices; "our reading" marks an interpretation. None of this is a forecast, a probability or a safety rating.

## Sources

- [NOAA National Hurricane Center: Tropical cyclone climatology](https://www.nhc.noaa.gov/climo/) (official), checked 29 Oct 2026.
- [NOAA National Hurricane Center: Glossary of NHC terms (tropical storm, hurricane, hurricane season)](https://www.nhc.noaa.gov/aboutgloss.shtml) (official), checked 29 Oct 2026.
- [NOAA National Hurricane Center: Atlantic hurricane database HURDAT2, 1851–2025](https://www.nhc.noaa.gov/data/#hurdat) (official), checked 29 Oct 2026.
- [National Meteorological Service of Belize: Climate summary](https://nms.gov.bz/climate-services/climate-summary/) (official), checked 29 Oct 2026.
- [Tyrlis & Lelieveld, Journal of the Atmospheric Sciences: Climatology and dynamics of the summer Etesian winds over the eastern Mediterranean (2013, 70(11): 3374–3396)](https://doi.org/10.1175/JAS-D-13-035.1) (peer-reviewed, not official), checked 29 Oct 2026.
- [DHMZ (Croatian Meteorological and Hydrological Service): Climate of Croatia: general characteristics](https://meteo.hr/klima_e.php?section=klima_hrvatska&param=k1) (official), checked 29 Oct 2026.
- [Land Development Department, Thailand: General climatic condition (monsoons)](https://webeng.ldd.go.th/pv/?cd=228) (official), checked 29 Oct 2026.
- [Météo-France Polynésie: Climat de la Polynésie](https://www.meteo.pf/fr/climat) (official), checked 29 Oct 2026.
- [Météo-France Polynésie: Perspectives pour la saison chaude 2026-2027](https://www.meteo.pf/fr/communiques-meteorologique/perspectives-pour-la-saison-chaude-2026-2027) (official), checked 29 Oct 2026.
- [NASA POWER: Prediction Of Worldwide Energy Resources: Daily API (WS10M_MAX, WD10M) and Monthly API (PRECTOTCORR)](https://power.larc.nasa.gov/docs/services/api/temporal/daily/) (official), checked 29 Oct 2026.
- [NASA POWER: Prediction Of Worldwide Energy Resources: Monthly API (T2M, WS10M)](https://power.larc.nasa.gov/docs/services/api/temporal/monthly/) (official), checked 28 Oct 2026.
- [Met Office: Beaufort wind force scale](https://weather.metoffice.gov.uk/guides/coast-and-sea/beaufort-scale) (official), checked 29 Oct 2026.
- [Tahiti Tourisme: Tahiti weather](https://tahititourisme.com/en-us/travel-planner/tahiti-weather/) (secondary, not official), checked 27 Oct 2026.

Method: [methodology](https://catamaranindex.com/methodology/#weatherrisk). Data: [JSON](https://catamaranindex.com/api/weather-risk.json).

## More

- [Weather risk in Croatia](https://catamaranindex.com/weather-risk/croatia/)
- [Weather risk in Greece](https://catamaranindex.com/weather-risk/greece/)
- [Weather risk in the BVI](https://catamaranindex.com/weather-risk/bvi/)
- [Weather risk in the Bahamas](https://catamaranindex.com/weather-risk/bahamas/)
- [Weather risk in Thailand](https://catamaranindex.com/weather-risk/thailand/)
- [Weather risk in French Polynesia](https://catamaranindex.com/weather-risk/french-polynesia/)
- [Weather risk in Belize](https://catamaranindex.com/weather-risk/belize/)
- [Best time to charter, by destination](https://catamaranindex.com/best-time/)
- [Best destinations for families](https://catamaranindex.com/family-yacht-charter/)
- [7-day sailing itineraries](https://catamaranindex.com/itineraries/)
- [Catamaran Index home](https://catamaranindex.com/)

## FAQ

### When is hurricane season for Caribbean charters?

The BVI's hurricane risk runs with the Atlantic hurricane season, 1 June to 30 November, with most activity between mid-August and mid-October (NOAA); in 1991–2020 a tropical storm or hurricane passed within 100 nm of Road Town, Tortola in 9 of 30 Augusts, and none in December to May (our count from NOAA's HURDAT2). If you book June to November, read your charter contract's hurricane clause and consider travel insurance that covers named storms; this is a historical frequency, not a forecast. More: [weather risk in the BVI](https://catamaranindex.com/weather-risk/bvi/).

### When is the meltemi?

The meltemi (the Etesian winds) is a persistent summer northerly over the Aegean, and its outbreaks are most frequent from mid-July to mid-August (peer-reviewed study, Tyrlis & Lelieveld 2013); at our Syros point in the Cyclades, days reaching force 6 (22 kn or more) average 4.9 in July and 4.7 in August, against 0.0 and 0.0 at Lefkada in the Ionian (our calculation from NASA POWER, 2016–2025). For lighter summer sailing the Ionian is the calmer choice in this data; the numbers are grid-cell means, not gusts, so plan sheltered alternatives and ask your base about the forecast each morning. More: [weather risk in Greece](https://catamaranindex.com/weather-risk/greece/).

### When does the bora blow in Croatia?

Croatia's two strong winds, the bora (north-easterly, gusty) and the jugo (southerly), "are more frequent and stronger in the cold part of the year", according to Croatia's national meteorological service (DHMZ); in summer the usual pattern is a daytime sea breeze and a north-westerly in the open sea. At our Split point, days reaching force 6 (22 kn or more) average 3.7 in November and 0.2 in July (our calculation from NASA POWER, 2016–2025), so a July or August charter rarely meets them, though DHMZ warns the summer bura can still disrupt sea traffic. More: [weather risk in Croatia](https://catamaranindex.com/weather-risk/croatia/).

### When is monsoon season in Phuket?

On Thailand's Andaman coast (Phuket), the rainy southwest monsoon usually runs from mid-May to mid-October and the northeast monsoon from mid-October to mid-February, according to Thailand's Land Development Department; our NASA POWER calculation at Ao Chalong gives about 266–360 mm of rain a month from June to September against 52 mm in February. Charter prices are lower in the monsoon months (see best time to charter in Thailand for the price data); ask your base which anchorages stay sheltered in a south-westerly, and expect some days in port. More: [weather risk in Thailand](https://catamaranindex.com/weather-risk/thailand/).

### When is the wet season in Tahiti?

French Polynesia's warm, wetter season runs November to April and its cooler, drier season May to October (Météo-France), and in the Society Islands the rainy season's wettest months are December and January; at Raiatea our NASA POWER calculation gives about 210 mm in December against 48 mm in August. For 2026–27, Météo-France's outlook of 26 October 2026 says El Niño has reached the "very strong" stage and lists the Society Islands among the areas with a high risk of at least one named tropical system between November 2026 and April 2027. More: [weather risk in French Polynesia](https://catamaranindex.com/weather-risk/french-polynesia/).

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