Weather in Jepara in September

A good month. September is a solid month to be in Jepara. Highs average 30.7 °C, lows 26.2 °C, and rain falls on 8 days — nothing in the month is working against you.

September ranks 3 of 12 in Jepara. Only August scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 8 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 30.7 °C days and 26.2 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 24 days top 30 °C, making the heat continuous rather than occasional; the day barely swings — 4.5 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest September day reached 32.9 °C and the coldest night fell to 23.7 °C, and the wettest single day dropped 30 mm — roughly 56% of the month's rain in one day.

This is the volatile part. September rainfall has ranged from 0 mm to 231 mm across the twenty years measured — a 231 mm spread around an average of 54 mm. The average is real but almost no individual September looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 12.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 70%.

How September sits in the year

Temperatures hold steady either side: 30 °C in August, 30.7 here, 30.6 in October. Nothing about the timing within the month matters much. Rain is the thing that moves: October brings 8 days more of it, so the earlier half of a flexible trip is the safer half.

Daylight in September

Jepara sits close enough to the equator that daylight barely moves all year — 12.1 hours in September, against a range of just 0.8 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 28.3 °C in September — warm enough that the water offers no relief from the heat. The sea peaks at 29.8 °C in April and bottoms out at 28.1 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Shoulder. The value months — prices ease off and you get the place closer to itself. September is the value pick for Jepara: it scores within 9 points of August without carrying August's prices.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

September in Jepara versus nearby

If Jepara is one option among several, the nearby comparison is worth making. Semarang is the weaker option in September — 4.7 °C warmer, 1 day less rain. Surabaya is close enough to be a coin toss — 3.1 °C warmer, 4 days less rain.

So: September works, with August the better month by 9 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Jepara

See all twelve months in Jepara, or where else to go in September.