Vienna/Prague/Budepest in March?

We usually go the last few days of March to get Winter airfares. And the weather in this region usually turns over to Spring about then. Early March might be a little more risky, however. A week or two does sometimes make a difference.
We were last in Budapest/Bratislava/Vienna/Prague 20 mos. ago, and we had just a great time. These are some really fine cities to visit.

Thanks so much David. By risky - do you mean rainy/snowy or just cold?

First week of March is still definitely winter. Plan on more time indoors. Too bad you can't come in spring when it will be nice to be outside. Everybody here, too, is just in such a bad mood by the end of winter, aching for the sun.

Weather in March in your cities is like playing lotto. You can be lucky. I remember years when in March was so warm that I swam outdoors although water was still icy cold. But it was that warm outside. I also remember years when it was snowing heavily practically blizzard. So the advice is: be prepared for almost like summer weather and also for winter. That's the disadvantage of going in March. The advantage is crowds will be thinner. Lines will be shorter.

My visit to those 3 cities (BTW Vienna should be visited between the other two to save time on transportation and avoid backtracking) was in mid-May. It wasn't really cold anywhere, but it was grey and very rainy in Budapest, grey and drizzly in Vienna until my last morning, and sunny in Prague. Much as I enjoyed Budapest and Vienna, the weather substantially detracted from the experience. I returned to Vienna last year in June and it was so much better, especially since the gardens were in bloom, and Vienna has several wonderful gardens in the centre.

On the other hand, Andalusia is the warmest, driest part of Europe. I've been twice, both times in February, and loved it. Barcelona too. Note that though they share a long border, transportation links between Spain and Portugal are sparse and slow. It's not easy to see both on one trip and there's enough in Spain to fill up your time and a very good high-speed train system.

Data for March 7:
Prague sunrise 6.33; sunset 5.55, day length 11 H 22M
Budapest sunrise 6.12; sunset 5.38, day length 11 H 25M
Sevilla sunrise 7.46; sunset 7.24, day length 11 H 37M
Barcelona sunrise 7.16; sunset 6.49, day length 11 H 33M

So while the length of the days is almost the same, unless you are really early risers, you'll have more daylight sightseeing time in Spain.

I have been in Budapest in March on a number of occasions. The out door cafes are beginning to open (with help from some heaters) and the sky is the most beautiful blue. But yes, chilly when you aren't in the sun. March 15 is the great holiday in Budapest. Not to be missed if you can arrange to be there. March/April and September/October are my two favorite times to be in Budapest.