Never Underestimate The Weather
Source: https://www.st-christophers.co.uk/
It seems like it always rains in Amsterdam. Briefly at best, but torrential rains can also happen suddenly. Even if it looks bright and sunny from your hotel window. Expect the unexpected. Always have a raincoat handy when outdoors. You may not need it, but if you do, you will be glad you brought it along. And wear footwear that is water repellent and anti-slip, just in case. Always be prepared for abrupt weather changes.