For quite a while I have been considering to provide you with a packing list for Hamburg. There is of course no “one list fits all”-solution, but I thought about a general guideline. Finally, I simply want to write about the one principle that is applicable for every season of the year: Pack clothes that can be worn as Zwiebellook, the layered onion look. Depending on the particular day, time, sunshine/clouds and the area you want to go to (e.g. the windy harbour), temperatures can feel quite different during your stay.
Also, do not check the Hamburg weather forecast two weeks ahead – the reality is, it can be quite different until you are here. If you are coming during summer, you may still encounter one of those surprisingly rainy and windy days that suddenly feel like autumn – keeping my fingers crossed that this is not going to happen. Equally, we already had the most wonderful days in the supposedly colder season, up to +20 °C in December! These are of course only exceptions, but be prepared and check Hamburg’s weather max. 3 days in advance.
Tip: When you are here and wonder if you need to carry your umbrella with you, I always like to have a quick look at the current Hamburg rain radar because blue sky can be as misleading as clouds.