Itinerary Help: Madrid in mid-September

What you have seems very workable to me. I assume Toledo is a day trip from Madrid. Fitting in Ronda would be difficult since isn’t close to any of the other cities you plan on visiting. Check the weather forecast a week or so before going over. When I was in Spain in early September 2014 there was a heat wave and it was near 100 degrees our entire trip. On that trip we visited all the cities you mentioned. In late September 2019, it was a little cooler in Madrid during the evening but we were still able to wear short sleeves.

Edited: I might disagree with the statement below about three days in Granada being too much. I agree that three FULL days is too much. However, by the time you get to Granada from Madrid and check into your hotel, most of that day is already filled. That would leave two full days to visit the Alhambra complex and the rest of the city. Since your partner hasn’t been there before, I think three nights is fine. Had you both already been there, I too would shave a day off that part of the trip.

Hi Benjamin, when you go to Toledo, make that a day trip from Madrid. If you go to Ronda, I would spend one day in Madrid since it’s not that pretty. However, you’ll miss seeing the Prado, but do try to see Picasso’s Guernica since it wouldn’t require a lot of energy as the Prado would. You need to be well rested when visiting museums, and trying to see one the size of the Prado the day you arrive is a bad idea.
You can take a direct 3h 30m train from Madrid to Granada, however, there’s no direct train from Granada to Ronda and requires one change (3h). Fortunately, there’s a 4h 15m direct train from Ronda to Madrid.

Sounds like Ronda is "a bridge too far" (literally) this time. It's theoretically about a two-hour drive from Granada, so could be a day trip with rental car, but you already have a lot of moving around in your short week. If you plan on traveling by train, then Toledo would be best as a day trip from Madrid. If you'll be driving, then you could overnight there on the way to Granada.

I think Madrid is worth more time than you're giving it, especially if you haven't been there before. But I like art museums (up to a point). The Prado alone was worth most of a day for me. Guernica is in the Reina Sofia museum near the Prado, and indeed an amazing experience, along with the nearby exhibits giving context about the Spanish Civil War. But that's a big museum too and takes awhile even if you look at nothing else.

To explain a bit further, in case you are not aware, Toledo is on a spur rail line connected only to Madrid. On a map it looks as if it's on the way to Cordoba/Seville/Granada, but if you wish to travel south from Toledo by train, you must first take a train back to Madrid's Atocha Station. Since you only have one day for Toledo, I'd agree that you might as well make it a day-trip from Madrid and save the time required to shift hotels.

Since you get to Madrid early in the morning, you could go right to Toledo for 2N, then Granada 2N, end in Madrid. Toledo is much better as an overnight so you have time before the daytrippers flood the town and after they leave. Not splitting your time in Madrid also means one less hotel change . . . or the same number of changes with more quality time in Toledo.

I'd expect it to be warm to hot in mid-September, hopefully with cool evenings. The best way to prepare is to look at daily weather conditions for any month for the last ten years here.

We loved Granada, but frankly, I think three days is too much there.
When doing Madrid, you should consider a day trip to Segovia. Beautiful small city with a Roman aqueduct that still functioned until the late 20th Century.

Toledo is of course a must see in Spain.

If you want to add a city, consider Cordoba. It is less than 2 hours by train from Madrid and and about 1 hour and 20-40 minutes to Granada on the faster trains. Well worth a visit. One day could be sufficient.

I would do what Chani said.... go straight to Toledo, stay 1 or 2 nights. It's a great place to recover from jet lag (relatively small -- you can walk everywhere -- but plenty to see). We did this on our last trip to Spain and loved it. If you don't want to deal with navigating public transportation from Barajas to Toledo (which is not all that hard, but impossible for me coming off an overnight flight), consider scheduling a private transfer or even catching a taxi. I've used SunTransfers a few times and had great experiences.

Then head to Granada for 2 or 3 nights. Like you, it's one of my favorite places. Three nights is not too much. I've stayed a total of weeks over multiple trips and am going back in December for more.

Then head back to Madrid so you can fly out easier at the end of your trip. And, if you have the time, think about stopping in Cordoba either on your way to or from Granada.

Have a great trip!