Weather in Semarang

Semarang is in Indonesia at 7.0°S. The 2001–2020 NASA POWER daily record describes a monsoon climate with a sharp wet-dry split. Rain is the monsoon runs from October to May, inside an annual total of 2057 mm. The wettest month is January at 354 mm; the driest is August at 31 mm.

October is the warmest month (average 29.2°C, high 34.0°C) and June is the coolest (average 26.3°C, low 22.8°C). From the coolest night in June (22.1°C) to the hottest afternoon in October (34.6°C), the raw range is 12.5°C. On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are June, July, and August.

When Semarang gets wet

The monsoon in Semarang starts in October and ends in May (October, November, December, January, February, March, April, and May). January is the core of it at 354 mm. August is the other extreme, with 31 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. January averages 28 such days; August averages 5.

Temperature through the year

Monthly average highs run from 29.8°C in June to 34.0°C in October. Nights follow the same curve: 22.8°C in June and 24.4°C in October.

Mean high across all twelve months is 30.7°C and mean low is 23.8°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

The calendar in Semarang

January is the wettest month — 354 mm and 28 rainy days, with 86% humidity. March stands apart from the months beside it: 29.1°C / 24.3°C and 204 mm. May closes the monsoon: 132 mm over 17 rainy days, then the calendar dries. The year bottoms out in June. Plan for 22.8°C at night and 29.8°C in the afternoon.

August is the driest month, averaging only 31 mm across 5 rainy days. Highs sit near 33.1°C. October is when the monsoon typically starts in Semarang: highs near 34.0°C, and rainfall jumps to 118 mm (15 rainy days). November: 31.3°C high, 24.7°C low, 205 mm rain, 77% humidity. December stands apart from the months beside it: 29.5°C / 24.5°C and 273 mm.

Best months to visit Semarang

The three months with the highest comfort score are June, July, and August: June (26.3°C average, 87 mm, 81% humidity); July (26.6°C average, 50 mm, 75% humidity); August (27.7°C average, 31 mm, 66% humidity). They fall in calendar order. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you want the monsoon itself — fewer crowds, greener landscape, heavier rain — aim at October–May instead of the score.

How Semarang compares inside Indonesia

Jepara is about 52 km away: Semarang is 0.7°C warmer than Jepara in its hottest month and 80 mm drier over the year than Jepara. Jepara’s wettest month is January (382 mm) versus January here.

Surabaya is about 259 km away: Semarang is 1.0°C cooler than Surabaya in its hottest month and 176 mm wetter over the year than Surabaya. Surabaya’s wettest month is January (337 mm) versus January here.

Bandung is about 311 km away: Semarang is 6.5°C warmer than Bandung in its hottest month and 548 mm drier over the year than Bandung. Bandung’s wettest month is February (365 mm) versus January here.