Seville in early March

Honestly, I think Sevilla would be marvelous in early/mid March. I was just there mid November and the weather was pretty perfect for us. Highs were between 60 and high 60s. It might have been 70 the first day. Absolutely there were people eating outside. They did have heaters. One night was a tad chilly and we specifically requested a table near the heater. I did pack and use one sweater. I like to bring a light weight wool or cashmere cardigan for layer. I also had a khaki jacket. I wore mostly elbow length or light weight long sleeved shirts and skirts/capris or light weight pants. The grass was green, there were leaves and oranges on the trees. For you, since it would be spring, I think the oranges would be gone but I am told that the variety of orange trees they have never lose their leaves.

I was there in the middle of March and the weather varied. I did eat out on una terraza a few times but it also was cold one night. However, l'd always go when there are less tourists so I'd say go for it. Seville is always beautiful.

My first two visits to Sevilla were in February. Both times, I sat outside with a friend for drinks in the afternoon sun, though I kept my fleece jacket on. My most recent visit was March 23-26 and there were a couple of days when I wished I had sandals with me.

Late February & first half of March is the usual time for orange trees to be in blossom, so you should be there at the ideal time for that. Of course, there are no guarantees with weather - even in southern Spain - but it's been a pretty normal winter here so far (high of about 65°F today, night low nearer freezing), and I don't think Seville has been very different from its usuals.

You will certainly be unlucky if you can't sit outside at cafes during the day (though you might occasionally have to shelter under the awnings, as it rains in March), but it gets cold in the evening after the sun goes down - a bit after 1900 hours, when you are there - and you might want to eat supper indoors.

PS if you look at temperatures locally, they will be quoted in °C, so don't forget to convert.