I'm graduating with my master's next December and want to treat myself with a trip when I'm finished! Spain (and possibly Portugal) is currently the destination of choice. I was hoping to go for about two weeks in April or May, but then realized that's right in the middle of the busy season at work. One option is to wait until the following September/October, but I was also thinking about late January/early February 2021. I'd want to hit the major stops in Andalucia (e.g. Sevilla, Cordoba, Granada). I can research the weather patterns, temps, etc., on my ow, but I'm looking for insight into peoples' experiences traveling to Spain at this time of year. Is there any reason people would recommend holding off until fall to go? I have done a decent amount of off-season travel (Budapest in November, Rome in January, Nice/Marseille in February) but want to make sure I'm not missing anything by going in the winter!
If you're wanting to research weather, go to Wikipedia and put in a specific city name. They often have a chart in yellow with average high temperatures, average lows, average precipitation, days/hours of sunshine and other information month by month.
The Algarve region of Southern Portugal has very mild weather and is almost of like Florida to the many U.K. vacationers that go there. Sometimes we travelers have to suck it up, and wear warmer (or cooler) clothes--depending on when we can travel.
I've been to Andalucia twice in February in the last 7 years, both times for about 3 weeks. Andalucia is the warmest, driest part of Europe. Most days were partly or fully sunny and in the 60s. I had a few cloudy days and even a little rain. Both Barcelona and Madrid were similar, though a bit cooler. For daily weather data, use the timeanddate.com past weather site. You can see daily conditions by month for the past 10 years.
I've enjoyed low season prices on rooms and few, if any, crowds at sights. What will you miss by going in winter, besides high prices and crowds (April/May - chock full of festivals)? Hmmm, not much. The gardens will be pruned back, so not as nice. I can't think of anything else.
Portugal gets the Atlantic breezes and tends to be cooler than Andalucia. I would save Portugal for a warmer season.
I think the Algarve is probably fairly mild in the winter, but most folks would agree that it's far from the most interesting part of Portugal. I'd expect the Atlantic Coast to be a good bit cooler than Andalucia. Comparing Lisbon to Seville, I see that Lisbon averages about 7 degrees (F) cooler, significantly more rain, and a lot more rainy days (15 per month rather than 6). I enjoyed Lisbon a lot, but I would not choose to go there in January-February.