Weather in Surabaya in April

Shoulder season. April is shoulder season in Surabaya — cheaper, quieter, and a genuine gamble. You should expect rain on 24 days of the month, which is more days wet than dry.

April ranks 9 of 12 in Surabaya: past the worst of the year but short of August, which is the month to book if the dates are open.

Rain on 24 of the month's 30 days, 7 of them heavy. At that frequency a wet-weather backup is not a contingency, it is the itinerary — book the indoor things first and treat the clear days as the bonus. Natural fibres and a second shirt for the day. At 82% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 13 days top 30 °C — hot spells arrive, but they break; the day barely swings — 3.4 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest April day reached 32 °C and the coldest night fell to 23.2 °C, and the wettest single day dropped 62 mm — roughly 32% of the month's rain in one day.

April is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest April on record still delivered 363 mm against 86 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 193 mm average is a reasonable planning figure, not a promise.

Wind is light at 7.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 82%, high enough to notice on the warm days without dominating them.

How April sits in the year

Temperatures hold steady either side: 29.2 °C in March, 29.8 here, 30.2 in May. Nothing about the timing within the month matters much. Rain is the thing that moves: May brings 6 days less of it, so pushing the dates later buys drier weather.

Daylight in April

Surabaya sits close enough to the equator that daylight barely moves all year — 12 hours in April, 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 29.8 °C in April — warm enough that the water offers no relief from the heat. This is the warmest the water gets all year.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

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

April in Surabaya versus nearby

If Surabaya is one option among several, the nearby comparison is worth making. Jepara is close enough to be a coin toss — within a degree on temperature, 2 days more rain. Semarang is close enough to be a coin toss — within a degree on temperature, 1 day less rain.

So: April is a compromise. August is 22 points better and is what Surabaya is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Surabaya

See all twelve months in Surabaya, or where else to go in April.