North Sumatra weather in September
September is one of the least pleasant months in North Sumatra: highs of 29°C (83°F) and about 261 mm (10.3 in) of rain on average. Nights average 23°C (73°F) and cloud cover 93% (NASA POWER, 2001–2025 averages). It is the 2nd wettest month of the year and the 6th coolest. Compared with August, it is about as warm and wetter; October brings highs of 28°C (83°F) and 310 mm (12.2 in) of rain.
Figures are long-term averages for Medan, the largest city in North Sumatra. See below for other places.
Is September a good time to visit North Sumatra?
least pleasant month Weather score 38/100.
September is one of the least pleasant months for weather in North Sumatra. For better conditions, consider Jun, Jan–Apr.
Does it rain a lot in North Sumatra in September?
Yes, it is one of the rainy months: about 261 mm (10.3 in) falls in an average September. It is the 2nd wettest month of the year.
How warm is North Sumatra in September?
Days average 29°C (83°F) and nights 23°C (73°F).
North Sumatra weather by month
| Month | High | Low | Rain | Cloud | Weather |
|---|---|---|---|---|---|
| January | 28°C (82°F) | 22°C (72°F) | 149 mm | 87% | best |
| February | 28°C (83°F) | 23°C (73°F) | 90 mm | 81% | best |
| March | 29°C (84°F) | 23°C (73°F) | 142 mm | 83% | best |
| April | 29°C (85°F) | 24°C (74°F) | 137 mm | 88% | best |
| May | 30°C (85°F) | 24°C (75°F) | 200 mm | 90% | fair |
| June | 29°C (85°F) | 23°C (74°F) | 137 mm | 86% | best |
| July | 29°C (84°F) | 23°C (73°F) | 168 mm | 88% | fair |
| August | 29°C (84°F) | 23°C (73°F) | 199 mm | 91% | fair |
| September | 29°C (83°F) | 23°C (73°F) | 261 mm | 93% | least pleasant |
| October | 28°C (83°F) | 23°C (73°F) | 310 mm | 94% | least pleasant |
| November | 28°C (82°F) | 23°C (73°F) | 233 mm | 95% | least pleasant |
| December | 28°C (82°F) | 23°C (73°F) | 250 mm | 92% | least pleasant |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis). Page updated . How we rate months
Weather across North Sumatra in September
Weather can differ a lot within North Sumatra: coasts, hills and mountains each have their own climate.
| Place | High | Low | Rain | Weather |
|---|---|---|---|---|
| Medan | 29°C (83°F) | 23°C (73°F) | 261 mm | least pleasant |
| Percut | 29°C (83°F) | 23°C (73°F) | 261 mm | least pleasant |
| Binjai | 29°C (83°F) | 23°C (73°F) | 261 mm | least pleasant |
| Pematangsiantar | 28°C (83°F) | 23°C (74°F) | 299 mm | least pleasant |
| Padangsidempuan | 26°C (78°F) | 20°C (68°F) | 390 mm | least pleasant |
| Tanjungbalai | 29°C (83°F) | 26°C (79°F) | 254 mm | least pleasant |
| Sunggal | 29°C (83°F) | 23°C (73°F) | 261 mm | least pleasant |
| Perbaungan | 29°C (83°F) | 23°C (73°F) | 261 mm | least pleasant |
| Kisaran | 28°C (83°F) | 23°C (74°F) | 299 mm | least pleasant |
| Gunungsitoli | 28°C (83°F) | 27°C (80°F) | 261 mm | least pleasant |
| Tebingtinggi | 29°C (84°F) | 27°C (80°F) | 275 mm | least pleasant |
| Rantauprapat | 29°C (83°F) | 23°C (73°F) | 351 mm | least pleasant |