Spain trip - April or May
 

I'm planning a 3 week trip around Spain for my parents (70s). My parents live in Florida and are sensitive to cold weather (under 70 degrees is cold). We have the option of two departure dates.

Option 1) April 14 - May 3
Barcelona (4/14-4/17), Madrid (4/18-4/21), Granada (4/22-4/24), Seville (4/25-4/28), Lisbon (4/29-5/3)

Option 2) May 19 - June 7
Barcelona (5/19-5/22), Madrid (5/23-5/26), Granada (5/27-5/29), Seville (5/30-6/2), Lisbon (6/3-6/7)

I'm concerned the April dates will be cold for Barcelona and Madrid, while the May dates will be hot for Seville. Unfortunately, they have a conflict for other dates in May.

Which dates would you recommend?

Here were the daily temps for April 2023 and May 2023 in Barcelona.

Daily temps for April 2023 and May 2023 in Madrid

Daily tempos for April 2023 and May 2023 in Granada

Daily temps for April 2023 and May 2023 in Seville

Daily temps for April 2023 and May 2023 in Lisbon

But with climate change all bets are off.
In general Spain is certainly heating up, and it's been exceptionally warm in April in Andalusia. From April well into September or even later you can expect very warm weather in the south.

Examples:
On September 29, 2023, the high reached 35C (95F) in Sevilla.
On October 3 the high there reached 33C (91F)
On November 15,the high reached 27C (almost 81F)

Thank you, this is a helpful start. Looks like Seville was very hot last April! Do most hotel rooms and indoor tourist spaces have air conditioning?

Yes, they have to! And some Seville hotels have rooftop pools, albeit small ones.

For me, April would be better if all else is equal. I was wearing cotton shirts in daytime in Madrid near the end of last March, with light jacket at night.

I will be going to Andalucia next week and planning to wear cotton blouse/t-shirt during the day, again, light jacket at night.
For Madrid I will bring a heavier (cotton) pullover, like a sweatshirt and my Uniqlo linen jacket (check it out..they are fabulous if still in stock..) and a nice quilted vest ($12 at Costco!)

So happy for you that you are taking this trip.

At night it may drop down to under 70 degrees in MID April in Madrid. The evening low could be from 8 to 10 C (upper 40s, low 50s)
Is under 70 degrees at night too cold for your parents?
During the day from April 14 on, last year's highs were from around 20-30C (from 68-86F). It varied a lot. In Madrid in March it was considerably colder at night, as ekscrunchy says, the need for a jacket or a light coat.

Is this trip for this year or for 2025? If in 2025, Holy Week will fall from Palm Sunday, April 13 to Easter Sunday, April 20.

The trip is for this year. I had already booked much of it for the April dates, but didn't realize the weather. Evening temperatures of 40s to 50s would be uncomfortably cold for them - they would need a heavier jacket or coat.

This is helpful. Thank you!

I just now paid attention to the number of nights in each location. It seems like a fairly fast paced itinerary but perhaps that's what your parents prefer.
Is the itinerary set in stone? I don't know whether lodging, flights and trains have already been booked.

Have you booked the Sevilla-Lisbon flight?
If not, could you change the order to Barcelona-Granada (via a flight), Seville (Granada to Seville bus or train), Madrid (Seville to Madrid via fast train) then finish in Lisbon after Madrid (via another flight, either Iberia or TAP)?

Or.. Barcelona to Sevilla (flight), from Sevilla to Granada (bus or train), then Granada to Madrid (fast AVE train), then Madrid-Lisbon (flight either via Iberia or TAP)?

Just wondering...

I've had trips to Barcelona in mid/late May that weren't exactly warm. Cold enough I had to scour the shops looking for a sweatshirt.

I'd go May and start in the south.

Also isn't there a fair or something in Seville mid/late April?

Thanks for the input and advice, everyone. We decided to move the trip to May. I think they will tolerate a few days of hotter weather (the usual for them) than several days of colder climate.