How hot is it in Mid-September in Lisbon and Porto areas?

End of Sept last year Lisbon was around 25C when we were there. Evora was +30 & along the Silver Coast was much cooler because of persistent fog.
Google avg temps for Sept shows 26C for Lisbon, Porto 24C.

The average temperature around that time in Lisbon and other parts of Portugal is between 65 and 79 degrees Farenheit. So, that would be an ideal time to vacation there.

We visited Portugal from September 18, 2017 thru October 10, 2017.
Lisboa, Coimbra, Aveiro. Porto, Lisboa.
We walked 8 km per day.
Thought the weather was perfect. We did sweat while walking.
It rained (in Aveiro) for 1/2 day during our 22-day vacation.

Thank you Marika, RJean, Davebarnes! Looks like it might be a bit on a hot side but not as bad as in August. Due to work schedule mid-September works best. Also, since I see more rain towards October that makes me worried since there are slopes and cobbled streets everywhere. Dry weather is definitely something I'd welcome!

So true how weather can be unpredictable. We toured Portugal early September 2016. When we arrived in Lisbon it was unusually warm. It was 40 degrees Celsius/ 104 degrees Fahrenheit. As we headed north, by the time we reached Porto mid September it was comfortable. Hopefully starting in mid September the temperature will be tolerable.

Janice, wow temperatures in the 40s?! I really hope it's an exeption rather than the norm! We visited Andalusia early in October and it was HOT but quite nice! As far as I see from posts and comments, Lisbon and Porto shouldn't be as hot as the South of Spain. So hopefully even though we travel somewhere around Sept 10-20, it would be ok. The other reason I am thinking earlier in Sept is safer is that it gets rainier as we go further in Sept - Oct. I really hope for dry (even if a little hot) weather. Hills + cobbled streets + rain = make me worried!

accuweather.com is the best website i’ve found and super helpful.

If you have the opportunity to start in Porto and end the trip in Lisbon, that would be good as it’s cooler in the north. I’ve been here the last three September’s and it’s quite warm. But, I’ve only seen 40C temps once and that was in August.
Plan on dressing for summer with maybe a light jacket for evenings. I also recommend accomodations with AC - especially in Lisbon.
And, I agree that warm weather is preferable to wet! Be sure to bring shoes with very good soles whether the weather is dry or wet. The cobblestones are a challenge for those of us who didn’t grow up walking on them...
Lastly, do some research on the elevators, escalators, funiculars, etc. in Lisbon - and one I know of in Porto. They are a great help in navigating the hills.

Thank you Susan and Kathrynj!
I think we'll need to invest into some good walking shoes with thicker soles and of course break them in before the trip! Someone posted somewhere to avoid bringing anything with thin soles. Kind of makes sense with all those cobbled streets.