Updated Tue 10:06 (America/Cancun)
Mexico · Forecast updated Sep 22, 2026, 10:06 UTC
Current Sea Temperature
29.9°C
85.8°F
Very warm water
Valid Sep 22, 2026, 10:06 (America/Cancun). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
0.3°C above
The typical September average is 29.6°C (85.3°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 29.5°C, versus 29.7°C in the prior seven days.
What to wear
Very warm water
Swimwear is usually enough; a rash guard adds sun protection.
Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions or replace the snorkel forecast.
In the historical baseline for Isla Mujeres, typical monthly averages range from about 26.6°C (79.9°F) in February to 29.6°C (85.3°F) in September.
Over the past 30 days, the average sea temperature in Isla Mujeres has been 29.6°C.
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Isla Mujeres, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 26.3–27.1°C | 26.7°C / 80.1°F |
| February | 26.3–26.8°C | 26.6°C / 79.9°F |
| March | 26.6–27.1°C | 26.9°C / 80.4°F |
| April | 27.1–27.4°C | 27.2°C / 81.0°F |
| May | 27.5–28.0°C | 27.7°C / 81.9°F |
| June | 28.5–28.8°C | 28.6°C / 83.5°F |
| July | 28.7–29.2°C | 29.0°C / 84.2°F |
| August | 28.5–29.5°C | 29.2°C / 84.6°F |
| September | 29.4–29.9°C | 29.6°C / 85.3°F |
| October | 29.1–29.6°C | 29.4°C / 84.9°F |
| November | 28.5–28.6°C | 28.5°C / 83.3°F |
| December | 27.1–28.0°C | 27.6°C / 81.7°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (21.21, -86.71). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
Each month uses the 2023–2025 baseline. The range is the lowest and highest yearly monthly mean, not an hourly extreme.
Typical January water temperature near Isla Mujeres is 26.7°C (80.1°F), with yearly monthly means from 26.3–27.1°C.
Typical February water temperature near Isla Mujeres is 26.6°C (79.9°F), with yearly monthly means from 26.3–26.8°C.
Typical March water temperature near Isla Mujeres is 26.9°C (80.4°F), with yearly monthly means from 26.6–27.1°C.
Typical April water temperature near Isla Mujeres is 27.2°C (81.0°F), with yearly monthly means from 27.1–27.4°C.
Typical May water temperature near Isla Mujeres is 27.7°C (81.9°F), with yearly monthly means from 27.5–28.0°C.
Typical June water temperature near Isla Mujeres is 28.6°C (83.5°F), with yearly monthly means from 28.5–28.8°C.
Typical July water temperature near Isla Mujeres is 29.0°C (84.2°F), with yearly monthly means from 28.7–29.2°C.
Typical August water temperature near Isla Mujeres is 29.2°C (84.6°F), with yearly monthly means from 28.5–29.5°C.
Typical September water temperature near Isla Mujeres is 29.6°C (85.3°F), with yearly monthly means from 29.4–29.9°C.
Typical October water temperature near Isla Mujeres is 29.4°C (84.9°F), with yearly monthly means from 29.1–29.6°C.
Typical November water temperature near Isla Mujeres is 28.5°C (83.3°F), with yearly monthly means from 28.5–28.6°C.
Typical December water temperature near Isla Mujeres is 27.6°C (81.7°F), with yearly monthly means from 27.1–28.0°C.
These values come from hourly forecasts SnorkelForecast has stored. They cover only months with records and do not replace the historical baseline.
| Month | Min | Average | Max |
|---|---|---|---|
| June | 27.8°C / 82.0°F | 28.4°C / 83.1°F | 29.2°C / 84.6°F |
| July | 28.2°C / 82.8°F | 28.9°C / 84.0°F | 29.9°C / 85.8°F |
| August | 28.0°C / 82.4°F | 29.1°C / 84.3°F | 30.0°C / 86.0°F |
| September | 28.6°C / 83.5°F | 29.9°C / 85.8°F | 31.0°C / 87.8°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2731 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
Island off Cancun with the MUSA underwater museum and summer whale sharks.
The current sea surface temperature near Isla Mujeres is 29.9°C (85.8°F). Over the last 30 days, the average has been 29.6°C.
The water is typically warmest in September, at around 29.6°C (85.3°F) in the 2023–2025 historical baseline.
The water is typically coldest in February, at around 26.6°C (79.9°F) in the same historical baseline.
At 29.9°C, the water is usually comfortable for swimming and snorkeling.
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See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Isla Mujeres.
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