All data are in degrees Fahrenheit

en

Water temperature in Isumi

Detailed information about the current water temperature in Isumi. 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 Isumi now

71.0

°F

November 8, 19:54

Trend:

stable

Yesterday:

70.4°F

Tomorrow:

70.4°F

Sunrise:

06:06

Sunset:

16:38

Day Length:

10 h. 32 min.

Isumi in November

Minimum:

58.4°F

Average:

62.3°F

Maximum:

64.7°F

Sea water temperature in Isumi today

As of now, in Isumi, the water temperature is 71.0°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 about the same as the average recorded on this particular day in recent years. Since yesterday, there was a slight increase in temperature. This indicates a warming trend over the past day. According to the forecast, we expect the temperature to fall a bit.

Recent sea temperature and forecast

Today's water temperature is considerably lower than the average registered over the last two weeks, indicating a slight cooling trend. It also falls within the range of the average temperature recorded for this date, suggesting a consistent weather trend. The maximum temperature recorded for this date was 73.0°F on 2016, while the historical minimum was 68.8°F on 2015.

The water temperature over the last two weeks displayed soome variability. While the two week average stayed close to the historical average, there were some days when the temperature was close to the histoorical minimum and others when it was close to the historical maximum. The forecast for the upcoming week shows a gradual cooling trend. The average temperature is expected to be 69.8°F, the minimum temperature may reach 69.1°F, and the maximum might stay at 70.4°F.

Daily water temperature in Isumi

Date Current Year

actual* / forecast**

last year 10 years average
Oct 25 76.2°F 76.4°F 73.5°F
Oct 26 75.8°F 76.0°F 73.0°F
Oct 27 74.0°F 76.6°F 72.7°F
Oct 28 75.6°F 76.0°F 73.0°F
Oct 29 75.2°F 75.6°F 72.5°F
Oct 30 74.0°F 75.3°F 72.1°F
Oct 31 73.7°F 72.8°F 71.7°F
Nov 1 72.9°F 74.8°F 71.7°F
Nov 2 71.5°F 74.6°F 71.6°F
Nov 3 71.3°F 73.2°F 71.3°F
Nov 4 70.6°F 73.2°F 71.9°F
Nov 5 71.0°F 75.0°F 71.9°F
Nov 6 70.9°F 74.5°F 71.7°F
Nov 7 70.4°F 71.6°F 71.2°F
Nov 8 71.0°F 71.8°F 71.0°F
Nov 9 70.4°F 71.2°F 70.4°F
Nov 10 70.1°F 70.9°F 70.1°F
Nov 11 70.3°F 71.1°F 70.3°F
Nov 12 69.9°F 70.7°F 69.8°F
Nov 13 69.1°F 69.9°F 69.0°F
Nov 14 69.4°F 70.2°F 69.4°F
Nov 15 69.6°F 70.4°F 69.6°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 Isumi by month

In Isumi, the months July through October offer comfortable swimming conditions, which amounts to 108 swimming days.
The warmest water in Isumi was recorded on August 17, 2024, reaching a 82.8°F. While the coldest temperature occurred on April 20, 2025, dipping to 53.1°F. The average readings by season are 62.1°F in Winter, 61.9°F in Spring, 74.2°F in Summer, and 73.9°F in Autumn.

Popular neighboring cities and resorts

City Water temperature* Distance**
Katsuura 71.5°F 8mi
Ichihara 64.4°F 27mi
Kisarazu 65.3°F 29mi
Chiba 64.0°F 30mi
Kimitsu 65.2°F 31mi
Futtsu 65.6°F 34mi
Honchō 61.6°F 40mi
Yokosuka 66.5°F 42mi
Kawasaki 63.5°F 44mi
Yokohama 65.2°F 45mi

* current water temperature in this city

** straight line distance from Isumi