מזג האוויר באוויירו בספטמבר

September is Porto's month: harvest in the Douro, warm days, and the river fog burns off by ten. Bring a layer for the Gaia side after sunset — it drops faster than you'd expect for the temperature shown.

Portugal forum posters describe November as a genuine lottery further north - you could get two weeks of steady rain or two weeks of mild, sunny days with cool evenings, and Aveiro's stretch of coast is squarely in the wetter, windier half of the country compared to the Algarve. When the sun does break through, daytime temperatures in the mid-to-high teens C feel pleasant for walking the canals, but forum regulars all say to pack a proper rain layer and expect a blustery day at some point - November is one of the wetter months here.

Forum posters describe May as bringing genuinely great weather for touring Aveiro's canals by traditional moliceiro boat - the roughly 45-minute round-trip cruise (about 13 euros) through the colorfully painted boats' historic waterways is repeatedly named the top thing to do in town, and posters specifically note it's best enjoyed on a nice-weather day rather than a rainy one. Portugal's broader spring pattern applies here too - generally mild and pleasant but with real day-to-day variability, so a layer for cooler mornings or an unexpected shower is sensible even during a generally good May stretch. Beyond the canal cruise, posters describe Aveiro as a compact, easily walkable town - often visited as a day trip from Porto - that pairs well with a relaxed, unhurried pace.