San Juan weather in October
In October, San Juan has daytime highs averaging 30 °C, nights around 24 °C, with 20 wet days, and a sea temperature of 29 °C. Figures are 1991–2020 climate normals.
- 30.3°C Average high
- 24.0°C Average low
- 20days Wet days
- 113mm Rainfall
- 28.9°C Sea temperature
- 12h Daylight
Daily temperatures through October
How October develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 October | 30.7 °C | 24.2 °C | 65 % |
| 11–20 October | 30.3 °C | 24.0 °C | 66 % |
| 21–31 October | 30.0 °C | 23.9 °C | 63 % |
What to expect
| Measure | Typical October | Share of the month |
|---|---|---|
| Days above 25 °C | 31 of 31 | 100 % |
| Days above 30 °C | 20 of 31 | 64 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 20 of 31 | 65 % |
Conditions in October
| Measure | Average |
|---|---|
| Mean temperature | 27 °C |
| Record high (1991–2020) | 35 °C |
| Record low (1991–2020) | 22 °C |
| Relative humidity | 84 % |
| Wind speed | 16 km/h |
| Cloud cover | 58 % |
Where San Juan ranks in October
| Ranking | Position | Value |
|---|---|---|
| The warmest places in North America in October | 24thof 50 | 30 °C |
October compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| August | 31.5 °C | 82 mm | 57 % |
| September | 31.1 °C | 128 mm | 63 % |
| October | 30.3 °C | 113 mm | 58 % |
| November | 28.9 °C | 105 mm | 52 % |
| December | 28.1 °C | 49 mm | 41 % |
See all twelve months for San Juan
- October is the 6th warmest month here.
- It is the 11th driest month of the year.
- It ranks 9th for least cloud cover.
- Days last about 12 hours from sunrise to sunset.
- It rains on 20 of 31 days — 65 % of the month.
- Nights are about 6.3 °C cooler than the middle of the day.
- The hottest October day on record since 1991 reached 35 °C, 4.7 °C above the usual daytime high.
- Beach score: 66 / 100 — see how this is calculated.
Nearby destinations in October
| Destination | Avg high | Wet days | Sea |
|---|---|---|---|
| San Juan | 30 °C | 20 | 29 |
| Carolina | 30 °C | 24 | 29 |
| Charlotte Amalie | 28 °C | 18 | 29 |
| Road Town | 28 °C | 17 | 29 |
| La Romana | 30 °C | 17 | 29 |
| San Pedro de Macorís | 29 °C | 17 | 29 |
| Gustavia | 28 °C | 17 | 29 |
| Basseterre | 28 °C | 18 | 29 |
| Santo Domingo | 29 °C | 21 | 29 |
QuestionsOctober in San Juan, answered
How warm is San Juan in October?
Daily highs average 30 °C and nights fall to about 24 °C, a spread of 6.3 °C between afternoon and dawn. That makes October the 5th warmest month of the year here.
Does it rain much in San Juan in October?
October averages 113 mm of rain, spread over about 20 of the 31 days — 65 % of the month. Cloud cover averages 58 % of the sky.
Is the sea warm enough to swim in October?
The sea averages 29 °C off San Juan in October. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in October?
San Juan averages 12 hours between sunrise and sunset in October. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.