All data are in degrees Fahrenheit

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Water temperature in San Juan

Detailed information about the current water temperature in San Juan. The trend over the last two weeks, daily averages, and precise forecast of the water temperature changes. Gain a deeper understanding of seasonal dynamics with monthly statistical analyses covering recent years.
Sea temperature in San Juan now

66.4

°F

September 14, 18:13

Trend:

decreasing

Yesterday:

67.5°F

Tomorrow:

66.0°F

Sunrise:

05:57

Sunset:

17:56

Day Length:

11 h. 59 min.

San Juan in September

Minimum:

60.9°F

Average:

65.3°F

Maximum:

68.9°F

Sea water temperature in San Juan today

As of now, in San Juan, the water temperature is 66.4°F. Swimming in water of this temperature is seen as relatively warm and enjoyable for some individuals, although many might find it slightly too cool. Today's reading is 8.6°F higher than the average recorded on this particular day in recent years. The sea temperature remains approximately unchanged from yesterday. According to the forecast, we expect the temperature to fall a bit.

Recent sea temperature and forecast

The water temperature today is above average for the last two weeks, showing a small increase in temperature. It is also close to the historical maximum temperature for this date. The maximum temperature recorded for this date was 60.8°F on 2023, while the historical minimum was 56.2°F on 2019.

Observations from the last two weeks indicate that the water temperature was in proximity to the highest values recorded on those days in the past. The forecast for the upcoming week shows a gradual cooling trend. The average temperature is expected to be 66.0°F, the minimum temperature may reach 65.8°F, and the maximum might stay at 66.2°F.

Daily water temperature in San Juan

Date Current Year

actual* / forecast**

last year 10 years average
Aug 31 65.5°F 56.6°F 58.7°F
Sep 1 65.2°F 57.0°F 58.7°F
Sep 2 64.7°F 56.9°F 58.4°F
Sep 3 63.5°F 56.9°F 58.0°F
Sep 4 64.1°F 56.9°F 58.3°F
Sep 5 62.9°F 56.3°F 58.0°F
Sep 6 62.8°F 56.7°F 57.9°F
Sep 7 63.6°F 58.1°F 58.1°F
Sep 8 64.6°F 57.8°F 58.4°F
Sep 9 67.8°F 56.2°F 58.5°F
Sep 10 68.5°F 56.7°F 58.4°F
Sep 11 68.6°F 56.8°F 58.5°F
Sep 12 68.2°F 57.5°F 58.6°F
Sep 13 67.5°F 57.4°F 58.7°F
Sep 14 66.4°F 57.7°F 57.8°F
Sep 15 66.0°F 57.3°F 57.5°F
Sep 16 66.0°F 57.3°F 57.5°F
Sep 17 65.8°F 57.1°F 57.2°F
Sep 18 65.9°F 58.1°F 57.4°F
Sep 19 66.0°F 57.3°F 57.4°F
Sep 20 66.2°F 57.5°F 57.6°F
Sep 21 66.1°F 58.0°F 57.5°F

* actual - actual temperature values

** forecast - projected values for the next week

Real-time coastal temperatures could deviate by several degrees from the provided readings. These deviations often become evident following intense rainfall or strong winds.

Our forecasting methodology leverages a mathematical model, that uses current water and weather conditions, historical records, wind intensity and direction.

Sea water temperature in San Juan by month

In an average year, San Juan offers no days when the water temperature is warm enough to swim comfortably.
The warmest water in San Juan was recorded on February 10, 2023, reaching a 72.2°F. While the coldest temperature occurred on October 19, 2021, dipping to 53.4°F. The average readings by season are 65.1°F in Winter, 63.3°F in Spring, 59.8°F in Summer, and 58.7°F in Autumn.