Saint Thomas, United States Virgin Islands
Caribbean Sea18.34°N, 64.94°WStation UN-SAI-SAP

Sapphire Beach Sea Water Temperature

A tropical beach on the Caribbean Sea, warmest around September at about 29.2°C. Today's reading, 7-day forecast, and monthly averages below.

Live readings · auto-updating
Water Temperature NowBuoy & Sentinel-3 SST

Sapphire Beach water temperature

29.2
84.6°FTropical Warm (> 28°C)

Very warm bath-like water. Zero chill, exceptional for relaxation and snorkeling.

+0°vs Sep avgCaribbean Sea18.34°N, 64.94°W
Activity Index:SwimmingSnorkelingSurfingTypical conditions
Marine Atmosphere Grid Live Marine Feed
Coastal Air
31°C
87.3°F onshore
Wind Speed
12 km/h
Surface wind
Wave Height
0.8 m
Slight shore chop
Swell
0.6 m
Deep water swell
Wave Period
6 s
Peak interval
UV Index
—
Daily maximum
Sunrise
—
First morning light
Sunset
—
Golden hour close

7-Day Water Temperature Forecast

Open-Meteo ocean model
Today
WedSep 30
29.2°C
84.6°F
Waves: 1m
Tropical
ThuOct 1
29.5°C
85.1°F
Waves: 0.9m
Tropical
FriOct 2
29.6°C
85.3°F
Waves: 0.7m
Tropical
SatOct 3
29.5°C
85.1°F
Waves: 0.6m
Tropical
SunOct 4
29.2°C
84.6°F
Waves: 0.7m
Tropical
MonOct 5
28.9°C
84°F
Waves: 0.9m
Tropical
TueOct 6
28.8°C
83.8°F
Waves: 1m
Tropical
Forecast cooling trend: -0.4°C over 7 days at Sapphire Beach.
Confidence: High

Sapphire Beach Monthly Water Temperature Averages

Historical monthly climatology. The warmest water in Sapphire Beach occurs inJanuary, February, March, April, May, June, July, August, September, October, November, December — peaking at29.2°C (84.6°F) in September.

Year-Round Water Temperature Curve (°C / °F)

Hover a bar for details
Current month Comfortable (20–24°C) Warm (24°C+) Cool (<20°C)
27
Jan
26
Feb
26
Mar
27
Apr
28
May
28
Jun
29
Jul
29
Aug
Current
29
Sep
29
Oct
29
Nov
27
Dec
Full 12-month data table — min / avg / max & swimming comfort
MonthMin Water TempAverage Water TempMax Water TempSwimming Comfort
January25.5°C26.5°C27.4°CWarm & Ideal (24°C – 28°C)
February25.5°C26.3°C27.1°CWarm & Ideal (24°C – 28°C)
March24.9°C26.3°C27.2°CWarm & Ideal (24°C – 28°C)
April25.9°C26.7°C27.7°CWarm & Ideal (24°C – 28°C)
May26.5°C27.5°C28.6°CWarm & Ideal (24°C – 28°C)
June27.2°C28.1°C29.3°CTropical Warm (> 28°C)
July27°C28.5°C29.5°CTropical Warm (> 28°C)
August28.1°C28.8°C29.7°CTropical Warm (> 28°C)
SeptemberCurrent28°C29.2°C29.9°CTropical Warm (> 28°C)
October27.6°C29.2°C30.6°CTropical Warm (> 28°C)
November27.6°C28.5°C29.7°CTropical Warm (> 28°C)
December26.6°C27.4°C28.8°CWarm & Ideal (24°C – 28°C)

Swimming FAQs for Sapphire Beach

Is the sea warm enough to swim in Sapphire Beach today?

Typical sea surface temperature in Sapphire Beach this time of year is 29.2°C (84.6°F) — classified as Tropical Warm (> 28°C). Very warm bath-like water. Zero chill, exceptional for relaxation and snorkeling. Live readings load automatically.

What are the warmest months for swimming in Sapphire Beach?

The highest water temperatures in Sapphire Beach typically occur duringJanuary, February, March, April, May, June, July, August, September, October, November, December, when monthly averages reach peak seasonal levels.

What is the typical water temperature in Sapphire Beach in September?

Historically in September, water temperatures in Sapphire Beach average around29.2°C (84.6°F), fluctuating between a recorded minimum of 28°C and a maximum of 29.9°C.

Other Beaches in United States Virgin Islands

Explore all United States Virgin Islands stations

Sapphire Beach Coastal Zone Map

Live OpenStreetMap