Rotterdam Weather by Month

Rotterdam’s climate is a classic temperate maritime type (Koppen Cfb), shaped by the North Sea about 25 kilometres to the west and by the city’s position near the mouth of the River Maas. You get mild, damp winters, cool and changeable summers, and rain that can arrive in any month rather than one defined wet season. The city sits largely below sea level, between 2 and 7 metres under the surrounding water table, which keeps humidity high and winter skies grey. This month by month breakdown gives you the exact temperatures, rainfall and sunshine hours to plan around.

Rotterdam Weather by Month: Winter (December to February)

Winter is cold but rarely bitter. January is the coldest month with an average high of 6.4°C (43.5°F) and a low of 1.3°C (34°F); February is almost identical at 7.1°C high and 1.1°C low. Overnight frost happens on roughly 45 to 60 nights per winter, but prolonged freezing is uncommon because the North Sea moderates the air. December averages 86mm of rain, January 71mm, February 66mm, spread over 11 to 14 wet days each. Sunshine is scarce: 55 hours in December, 70 in January and 90 in February, so daylight fades by 4:30 PM in mid-December. Snow is possible a few days a year but rarely settles for long. The full comparison table is below.

Rotterdam Weather by Month: Spring (March to May)

Spring is the driest stretch of the year. March averages a 10.3°C (50.5°F) high with 56mm of rain, April warms to 14.3°C (58°F) with just 42mm, and May reaches 17.9°C (64°F) with 56mm. April is the driest month of the entire year, which is why King’s Day on April 27 usually stays dry enough for street parties. Sunshine climbs fast, from 145 hours in March to 195 in April and 225 in May, the sunniest month of the year. Expect occasional cold snaps in early March and the chance of a warm, almost summery spell by late May.

Rotterdam Weather by Month: Summer (June to August)

Summer is mild rather than hot. July is the warmest month at a 22.7°C (72.9°F) average high and 13.4°C low; August is nearly the same at 22.6°C. June averages 20.6°C (69°F). Heatwaves above 30°C (86°F) happen 2 to 3 times a summer in 3 to 5 day stretches, but they never run long. Rain picks up through the season: June 69mm, July 79mm, and August is the wettest month of the year at 92mm across 11 days, often as brief afternoon showers. Sunshine stays strong at 215 hours in June, 220 in July and 200 in August, with daylight lasting past 10 PM in late June. If you want to pair this with a city break, check the best time to visit Rotterdam guide.

Rotterdam Weather by Month: Autumn (September to November)

Autumn starts mild and turns grey and wet. September still feels like an extension of summer at 19.3°C (66.7°F) and 155 sunshine hours, but it brings 90mm of rain. October cools to 14.9°C (59°F) with 87mm, and November drops to 10.2°C (50°F) with 88mm over 14 wet days, tying winter as the greyest stretch of the year. November and December are the darkest months, with only 65 and 55 sunshine hours. Pack a waterproof shell and expect short days from October onward.

Rotterdam Weather by Month: Comparison Table

The annual picture: 880mm of rain across about 134 wet days, roughly 1,750 hours of sunshine, and a yearly average temperature of 10.6°C (51°F). Rotterdam is not a beach destination, so there is no meaningful sea temperature to report, but the nearby North Sea at Hoek van Holland ranges from about 6°C (43°F) in February to 18°C (64°F) in August if you plan a day trip to the coast. For a full rundown of what to pack and when to come, read the best time to visit Rotterdam guide and the things to do in Rotterdam list.