Karimunjawa Sea Temperature

The chart above plots the daily sea temperature at Karimunjawa over the last 30 days. Each point is one day, blended from the most recent reading for the area and the 10-year average for the same day of the year. Hovering the chart pulls up the exact date and temperature for that day.

A rising line usually means the water is warming through a season. A flatter line means the surface has settled into the typical range. Short-lived dips can show storm mixing or a run of cold winds, and a sudden jump can show a warm-water push from an ocean current or a heatwave overhead.

The numbers down the left edge are temperatures, on the same scale as the values in the 30-day table below. The temperature toggle in the top bar flips the whole page between Celsius and Fahrenheit, including this chart.

The table above lists the last 30 days of water temperature for Karimunjawa, newest at the top. Each row shows the sea surface temperature in both Celsius and Fahrenheit, so the value works for either side of the Atlantic without a unit switch.

Day-to-day swings of a degree or two are normal even in settled weather. Bigger jumps usually line up with weather events. Reading the table next to the chart above is the easiest way to see whether the line is moving with the season or against it.

The data blends the most recent reading for the area with the 10-year average for the same day of the year, so the trend stays continuous even on days where a fresh reading isn't available.

The chart above shows what the water at Karimunjawa usually does across the year. Each bar covers the historical range from low to high for that month, and the line inside the bar is the 10-year monthly average. Together they show the typical span you can expect from any given month, not just a single point estimate.

Coastal water lags the air by a few weeks. The warmest month here often sits a month or two after the warmest air temperature, and the coldest month sits the same distance behind the coldest air. A wide bar means the month covers more spread between cold years and warm years; a narrow bar means the water settles into a tight range that month.

For a closer look at any single month, including the day-by-day range and a temperature table, choose a month from the panel below.

Karimunjawa sits at -5.8336°N, 110.4506°E, on the coast of Indonesia. The marker on the map shows the spot the readings on this page come from. It usually sits a short distance from the town centre, out on the open water itself, so the numbers stay tied to the coast rather than a generic point inland.

Coastlines bend, headlands focus the water, and the temperature can run noticeably differently between two beaches that look close together on a map. Comparing nearby locations is a quick way to see how local geography is shaping the readings.

Nearest locations to Karimunjawa

• Karimun Jawa Road, 6.7 km SW
• Kenanti, 98 km SE
• Bonang, 115 km S
• Semerang (Tanjung Emas), 124 km S
• Tambakrejo, 125 km S
• Semarang, 130 km S

Karimunjawa sits on the coast of Indonesia. The numbers on this page are daily sea temperature readings for the closest stretch of open water, blended with a 10-year average so the trend stays continuous even on the odd day where a fresh reading isn't available.

Across a typical year the water at Karimunjawa averages around 29.13° C. The warmest stretch is usually November, when the average climbs to about 29.83° C, and the coolest is February, when it sits around 28.44° C. The water lags the air by a few weeks, so the warmest month often arrives a little after the warmest air temperature, and the coldest month a little after the coldest.

Sea temperature is a useful planning number for swimmers, surfers, sailors, and anyone working near the coast. It is not a safety forecast. Local conditions can vary by several degrees from what's shown here: shallow bays warm faster, deep harbours stay cold, river mouths cut the temperature locally, and strong onshore winds can pull cold water up from depth.