Spain and heatwaves

Averages are of questionable use. They hide extremes, and it's the extremes that can make you miserable. I do weather research by checking actual, historical, day-by-day temperature statistics on the website timeanddate.com. I usually look at the most recent 5 years. I don't know what cities your tour visits or what month you plan to travel, but this will get you started:

Seville April 2023

Barcelona April 2023

Use the Search box at the upper right to change the city. Use the pull-down box at the right just above the graph to change the month and year displayed.

I generally use the monthly-average precipitation statistics in the cities' Wikipedia entries to anticipate rainfall. I don't know how accurate they are now, because the averages are usually based on a period ending in either 2000 or 2010.

Spain is a big country with varied climates and weather patterns, though I think April you should be good to go for most of Spain, actually April is one of the rainiest times in most of Spain.

I agree with Carlos. I've been to Spain in April on a number of occasions and experienced rain. Once had a week of almost non stop rain in Marbella, I would have preferred a heatwave!

We have been in Spain since Oct 1 and weather was fine. A little hot of some days but bearable.

I too agree with Carlos. Yes, last year parts of Spain did have warmer weather than normal, but normally most of Spain is very pleasant in the spring. I check the weather a few weeks out to get an idea of the trend and pack accordingly. The temperature in the spring isn’t even a consideration when deciding where to go.

We were there in early May in 2015, and it was incredibly hot in Madrid: ~105 F. We thought that we had chosen a time of year when the weather would be quite mild, but that turned out not to be the case. That said, it wasn't unbearable, because our hotel had air conditioning, the museums were cool, and Retiro Park provided a nice escape from the intense heat. Also, it was a dry heat, which I find easier to take than heat with high humidity.

Barcelona was a lot cooler, and was downright cold (and rainy) one day.

The very first comment, acraven’s, makes a couple of great points that I want to expand on a just little. First, I agree that average weather statistics are not always of great use, and as a research statistician by profession, I would go further and add that in my opinion, the naive infatuation that the media and the public have for “grand averages,” to the exclusion of all other relevant statistics, has led mainly to a lot of misunderstanding in all areas (weather, hotel and dining prices, crime levels, poverty levels, economic strength, etc.)

Second, I too have found the “timeanddate” site to be useful in anticipating the weather I may encounter when travelling. I’ll note that in addition to daily high and low temperatures for several preceding years, and for numerous cities around the world, the site also gives daily humidity and precipitation data, and if for some reason you need them, even wind speed and direction!

Thank you everyone, these are all helpful comments.