Northern Spain vs Southern Spain Sept/Oct

You have your N & S mixed up in the list of places. Anyway, the odds of better weather will be greater in the south - where it is too hot for many in the summer.

If you are using the trains, Renfe is the national operator but beware - their website does not show competing high speed train operators using the same tracks on certain routes.https://www.thetrainline.com does show the competing train operators and I would suggest you set the currency to Euros.

Where the weather will be better depends to some degree on your relative tolerance for heat (still a major potential issue in Seville/Cordoba at that time of year) vs. overcast/cool/rainy weather (possible at just about any time of year along the northern coast). You cannot count on beach weather along the northern coast on any particular day, even in July.

I'd suggest looking at the actual, historical, day-by-day weather statistics available on the website timeanddate.com to see the range of what you might experience in either area. Here's a link for Seville (with Cordoba, the hottest place on your list of options):

Seville weather -- September 2024

Use the pull-down box at the right, just above the graph, to change the month and year displayed. I like to check the most recent 5 years.

Use the Search box at the upper right to change the location.

Spain may be the most heterogeneous country in Europe, in terms of food, landscapes, climates, traditions, temperatures...and even looks. Northern Spain is wet, green, cool, mountainous (you can find mountains all over Spain, it´s the second most mountainous country in Europe), beautiful valleys and rough sea (this is the Atlantic). The South is also mountainous, but normally much drier and much warmer than the north. Two different worlds, Spain is a very diverse country. Just wondering what Terranova is (In Spanish, Terranova is Newfoundland!)

I have been all over Spain and love it all. My favorite cities are Toledo and Seville, but I loved the Basque region, Salamanca and Galacia as well.

One thing, I did visit Costa del Sol beaches and was a bit disappointing, they are not as nice at what you get in Florida or California.

I think that would be late enough for the heat in the south to have abated, and I don't know the rain stats for the north (like acraven, I make good use of weather websites for those details!). However, I don't think this is a weather conundrum but a question of which you wish to see more. They are so different to feel like completely different countries.
Since you would probably not be swimming but just enjoying the views and vibe of the seaside, I would be more drawn to the wild beaches of the north. The south is less impressive, though there are some nice stretches like east of Cadiz that I thought quite pretty. Both are seafood meccas (ekscrunchy can give you tons of ideas there).
I think you would want a car in the north if you intend to explore nature. In the south, the train system is so extensive that it is not necessary unless you really want to get out into the parks and such.
I'd keep digging though a comprehensive guide book like a Rough Guide to see what stands out. Things to figure out: do you want cities or small villages/countryside? (I am not seeing a lot of the latter in your proposed itineraries, though you said that was what you wanted). Second the transport issue--car for a portion or not at all?

My guess is Terranova was autocorrected and should be Tarragona.

Southern Span could still be very warm in late September, but that wouldn’t stop me from visiting there. On my last trip to southern Spain in 2014 the temperature was in the 90s on most days. It really depends on what you want to do and see. Each is unique geographically and both are worth visiting. I don’t prefer one over the other and would happily visit each any chance I got.

We tend to visit small cities and villages and avoid the large cities since many are not major tourist destinations and the crowds are fewer. Because of where we visit, we always get a rental car. Other than Ronda the places on your list should be readily accessible using public transportation.

Hi All ! Thank you for your responses. I did get N & S mixed up (oops!), These are really good things to consider and I guess to boil it down, I think we are trying to figure out which area is better to visit on your first trip to Spain. We do love some of the smaller towns and do want some bigger cities. I did mis-spell Tarragona. We are open to renting a car and have rented cars in other countries, so sounds like that is what we should do if we are going to do N Spain. I think we would also want to probably do high sped train. In looking at some of the areas, both just have such different and beautiful architecture. I wish we had time to do it all. Thanks again for all of the advice. If you think of anything else, please comment. I am open to all suggestions and thoughts.
Thank you!!

The good news is you can't go wrong--either would be great. I don't ascribe much to the idea that you should do a certain thing or see a certain place just because it is your first trip--they are both "authentically Spain." Maybe sketch out a few dummy plans and see what looks most appealing. You may need to scale back your list either way if you would like to get into the countryside, but that is where playing around with itineraries can really help you visualize.
I've got two trips to the south under my belt, one fantastic trip to the center, but my one trip to the north was also very memorable, and because the heat can really limit time of year you want to visit the south, I do have to say I would be very drawn to the north in early fall (I typically travel in spring when the rain would keep me away).
Madrid is so easy to fly to so I never feel bad about skipping it or giving it short shrift--it will be there later when I return!

The idea of a list is a good one. Put everything you’d like to see at each location on it. Once there you won’t overlook something you wanted to see and can prioritize places close together. When time runs out, you just skip what you didn’t have time for.

I bookmark places on Google maps and make stops en route. There are always more things on my list than time to see them, but I know that before the trip starts. Better to have more things planned than to run out and waste time figuring out what to do.

The google maps tip is a good one. I agree, better to have already researched and have a list and then once there, skip whateer you don't want to do or have time for. Thanks, everyone!

Public transport is great all over Spain, and particularly in northern Spain. Buses are always an excellent option and take you to more places than trains, and are preferred by locals in most of Spain, so take this into account when deciding on renting a car or not.