12 Weeks

You don't mention if this is one place or a handful of cities. If one, the season might matter more (and for most of the country, the answer would probably be fall. If it's spread over 3-5 cities/towns, the season could chase better weather.

(In any case, February and March are dodgy months for weather in up to three-quarters of the country. Cold rain has its charms, but if you have a choice...)

Without having done weather research (which I think is important), I'd go with late-February until early May. You'll have longer days than if you travel in the fall. I'd structure the itinerary so that Andalucia falls at the coolest time of the trip and the Basque Country, Galicia and the Pyrenees at the warmest time.

Both of us are vegan, so ready access to good quality produce is important.

What are the produce crops in Spain, and will you have better luck spring or fall getting great stuff in season?

I'd go with September-October-November, that's a fairly predictable time weather wise. You can start north and work your way south as it get cooler. Plus it will be harvest time then!

Tough call since April-May and September-October are both good times to travel there. The February, March, and November months are when you could get some winter weather, especially in the north. In late May 2017 when we stopped in O Cebreiro east of Santiago de Compostela the temperature was 32 degrees at mid-day. If there are any special festivals you wanted to attend, maybe those might dictate when you go. Another option would be to plan southern Spain for the colder months and save the north for warmer months. I’m assuming you will be moving around on the trip.

I too would go Sep, Oct, Nov. This is the perfect time to be in Europe.

I vote for Spring: Holy week should not be missed, wild flowers, green hills, and baby animals in the mountains. I have been 3 times in Spring and once end of September/early Oct. (too hot for me). Either way I wish this was a problem I had, enjoy your trip J

I've only been to Spain in February and March, in Barcelona, Madrid, Andalucia. I've taken 3 trips, each 3 weeks long, plus another long weekend in Barcelona (I couldn't resist).

I found lots of vegetarian options and lots of fresh fruit and veg in the markets. The markets I've been to were all in large, airy buildings, though I didn't look for any in the villages I visited.

There are lots of festivals in late winter and spring - Carnival is big in Cadiz, Semana Santa (Palm Sunday to Easter) is huge in Andalucia and a few other places, Jerez has a horse fair, Sevilla has a spring fair, Valencia has Las Fallas in mid-March, Cordoba has a patio festival. In March all the orange trees were in bloom, heady scent everywhere.

As for weather . . . I avoid the heat, so I've never wanted to go in September or even into mid-October when much of Spain can still be hot. I was told by a native of Bilbao that the best time of year to visit Galicia and the Basque region is September/October. While I've had some chilly days and some rain in February, most of the time, the weather was in the 50s and 60s and sunny. Another consideration is daylight. Days lengthen from February and DST kicks in in late March. Days shorten from September and DST ends in October. You can get a lot of info at timeanddate.com. Sunrise etc here and historical weather data here.

Okay, it would not be the entire time in one place, but I don't know yet how many places it might be. At least three, maybe even six, with day trips. It won't be until at least next year, perhaps even 2024, as we are not inclined to travel at present. LOL, that feels kind of strange, having been "on the road" in the RV for so many years, followed by part of the time in Europe and the rest in the RV. Except the last two years, sigh.

So, yes, it is logical to follow the weather. I've been watching a number of locations for some months now, but it feels like "normal" doesn't seem to exist anymore. And that phenomenon known as La Calima, oh, that's a doozy!

I do have some reserves in at the library, but it seems I have to wait my turn. RS new Spain book is supposed to be released in September, but in the meantime, well, the sights didn't move, so old books will suffice for initial research.

As for crops, I seem to remember getting Spanish produce in the Albert Heijn stores in the Netherlands in the spring. It's pretty interesting, the way it's all labeled in Europe. Wish that was the case in the US.

I will have to research festivals and other special events.

We have been to Spain once. It was the last country in an almost eight month trip. We sailed back to Florida from Barcelona in early November. Unfortunately, we picked up a really nasty cold on the flight from Athens, so most of our month in Spain was less that it was supposed to be. We did manage to see La Mezquita and the Alhambra, a few patios that are open year round, as well as some of the architectural options in Barcelona. And then I got sick on the cruise home, bah, damn norovirus.

I thank you all for your responses.