Hello :)
I'll stay in Lisbon from September till February. I don't know what type of clothes should I pack: do I need rain boots or thick clothing? Or a light leather jacket and cardigans are enough?
Thank you!

Hello :)
I'll stay in Lisbon from September till February. I don't know what type of clothes should I pack: do I need rain boots or thick clothing? Or a light leather jacket and cardigans are enough?
Thank you!

I envy you - just finished my own long stay in Lisbon, from January to end June :) It was amazing!
It can rain a lot at times, in particular during winter months, so some boots which wouldn't get soaked in 15 minutes would be a plus. This year it rained almost daily for a month or so in January/February. However, it rarely rains the whole day, most often it's rather a shower and sun may shine a few hours later. The temperature will rarely drop below 14 degrees. Be prepared for quite strong wind as well, the ocean is near.
In Sept to Oct you can expect similar weather like in Romania, if that's where you live.
Winters in Portugal are much milder though - rain and no snow, with temps between 10 and 18 C. A leather jacket and jumper will be all you need.

Most houses in Portugal do not have heating. You are usually given an electric heater. So when its +14C outside, you'll be surprised how cold Nov-Feb can get indoors. The question is not whether or not you'll need a cardigan, its how many you can put on at the same time.
The temperature will rarely drop below 14 degrees.
Did we live in the same Portugal?
Last December:
http://www.tutiempo.net/clima/Lisboa_Portela/12-2013/85360.htm
+14.6C is the average MAXIMUM temperature, but this is only attained for a short period during the day. The daily average temp was only +10.7C and there are days with an average temperature of only +7C