# Mayagüez in September: weather

Mayagüez, Puerto Rico (Caribbean). Ten-year climatology (2015-2024), not a forecast. Page: https://beaufixe.net/en/weather/mayaguez/september

## Key figures

| Indicator | Value |
|---|---|
| Afternoon (mean daily max) | 30.8 °C |
| Night (mean daily min) | 23.9 °C |
| Sea (surface) | 29.8 °C |
| Rainy days (≥ 1 mm) | 23 / month |
| Relative humidity | 81 % |
| Probability of a 25 °C+ afternoon | 100 % |

## Month by month

| Month | Afternoon | Night | Sea | Rain (d) |
|---|---|---|---|---|
| January | 28.6 °C | 20.6 °C | 27.3 °C | 13 |
| February | 28.8 °C | 20.6 °C | 27.1 °C | 14 |
| March | 28.7 °C | 20.8 °C | 27.1 °C | 17 |
| April | 29.3 °C | 21.2 °C | 27.6 °C | 22 |
| May | 30.2 °C | 22.5 °C | 28.2 °C | 21 |
| June | 31.1 °C | 23.1 °C | 28.8 °C | 22 |
| July | 31.3 °C | 23.5 °C | 28.9 °C | 23 |
| August | 31.3 °C | 23.8 °C | 29.3 °C | 24 |
| September | 30.8 °C | 23.9 °C | 29.8 °C | 23 |
| October | 30.3 °C | 23.4 °C | 29.6 °C | 23 |
| November | 29.2 °C | 22.5 °C | 29 °C | 20 |
| December | 29.1 °C | 21.6 °C | 28.1 °C | 14 |

Best months : January, December, February.

## Before you go

- **Safety** : No specific restrictions. Usual precautions apply. (official advice updated 18 August 2026 — https://www.gov.uk/foreign-travel-advice/usa)
- **Entry** (British passport) : No visa, but an electronic travel authorisation (ESTA) must be obtained online before departure. Passport valid until your return date. FCDO page for the USA: ESTA (with selfie photo) or visa before travel; not eligible after travel to Cuba since 12 January 2021 or to listed countries. (per the UK Foreign Office, 18 August 2026)
- **Vaccines** : hepatitis A and hepatitis B if you are not already vaccinated. Routine vaccines up to date (measles in particular).
- **Yellow fever** : No yellow fever locally, vaccine not recommended. No entry requirement.
- **Malaria** : None.
- **Mosquitoes** : dengue and Zika reported: protect yourself from bites.
  (per the CDC, page reviewed 25 August 2026 — https://wwwnc.cdc.gov/travel/destinations/traveler/none/puerto-rico)

## Sources

Air, rain, humidity: ERA5-Land reanalysis (Copernicus) served by Open-Meteo (CC BY 4.0). Sea: NOAA OISST. Safety: FCDO (OGL v3), zones reviewed by Beau Fixe. Entry: France Diplomatie (Licence Ouverte 2.0) / FCDO. Health: CDC (public domain). Details: https://beaufixe.net/en/legal#sources

Beau Fixe — https://beaufixe.net — not a forecast; only the authorities are authoritative for safety, entry rules and health.