Rotterdam weather in September
September is one of the best months to visit Rotterdam: highs of 19°C (66°F) and about 70 mm (2.8 in) of rain on average. Nights average 13°C (55°F) and cloud cover 61% (NASA POWER, 2001–2025 averages). The sea averages 19°C (65°F). It is the 6th driest month of the year and the 4th warmest. Compared with August, it is cooler and drier; October brings highs of 15°C (58°F) and 79 mm (3.1 in) of rain.
Is September a good time to visit Rotterdam?
best month Weather score 73/100.
Yes. September is one of the best months for weather in Rotterdam.
Does it rain a lot in Rotterdam in September?
Some rain is normal: about 70 mm (2.8 in) falls in an average September. It is the 6th driest month of the year.
How warm is Rotterdam in September?
Days average 19°C (66°F) and nights 13°C (55°F).
Rotterdam weather by month
| Month | High | Low | Rain | Cloud | Sea | Weather |
|---|---|---|---|---|---|---|
| January | 6°C (42°F) | 2°C (36°F) | 77 mm | 74% | 6°C (43°F) | least pleasant |
| February | 6°C (43°F) | 2°C (35°F) | 66 mm | 72% | 6°C (43°F) | least pleasant |
| March | 9°C (47°F) | 3°C (38°F) | 55 mm | 66% | 8°C (46°F) | least pleasant |
| April | 13°C (55°F) | 6°C (42°F) | 38 mm | 61% | 11°C (51°F) | fair |
| May | 16°C (61°F) | 9°C (49°F) | 56 mm | 65% | 14°C (57°F) | best |
| June | 19°C (66°F) | 13°C (55°F) | 62 mm | 67% | 17°C (63°F) | best |
| July | 21°C (70°F) | 15°C (59°F) | 78 mm | 64% | 20°C (68°F) | best |
| August | 21°C (71°F) | 15°C (59°F) | 87 mm | 64% | 21°C (69°F) | best |
| September | 19°C (66°F) | 13°C (55°F) | 70 mm | 61% | 19°C (65°F) | best |
| October | 15°C (58°F) | 10°C (49°F) | 79 mm | 68% | 15°C (58°F) | fair |
| November | 10°C (50°F) | 6°C (43°F) | 81 mm | 73% | 11°C (52°F) | least pleasant |
| December | 7°C (44°F) | 3°C (38°F) | 85 mm | 74% | 8°C (46°F) | least pleasant |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine. Page updated . How we rate months