Amsterdam has an oceanic climate strongly influenced by its proximity to the North Sea to the west, with prevailing westerly winds. While winters are cool and summers warm, temperatures vary year by year. There can occasionally be cold, snowy winters and hot, humid summers.
Amsterdam, as well as most of the North Holland province, lies in USDA Hardiness zone 8b. Frosts mainly occur during spells of easterly or northeasterly winds from the inner European continent. Even then, because Amsterdam is surrounded on three sides by large bodies of water, as well as having a significant heat-island effect, nights rarely fall below −5 °C (23 °F), while it could easily be −12 °C (10 °F) in Hilversum, 25 km (16 mi) southeast.
Summers are moderately warm with a number of hot days every month. The average daily high in August is 22.1 °C (72 °F), and 30 °C (86 °F) or higher is only measured on average on 2.5 days, placing Amsterdam in AHS Heat Zone 2. The record extremes range from −19.7 °C (−3.5 °F) to 36.3 °C (97.3 °F).
Days with more than 1 mm (0.04 in) of precipitation are common, on average 133 days per year.
Amsterdam’s average annual precipitation is 838 mm (33 in). A large part of this precipitation falls as light rain or brief showers. Cloudy and damp days are common during the cooler months of October through March.