Hi I will be in Milan at the 18th of may.want to take train to Lugano for swimming and hanging in town. Is it warm enough and where is this lido located. I will be coming by train. Thank you
The Lido di Lugano appears to be a public swimming pool, so it should be warm enough. I doubt that the water in the lake will be warm enough at that time of year.
The map on the attached website shows where it's located (right in town, easy access). There's a large park in the vicinity of the Casino, and it's only a short distance from there, just off Viale Castagnola.
As you're coming by train, you'll have to get from the station (which is on the hill above town) into the town, either via the Funicular or Taxi. It's walkable but if you're unfamiliar with the city, a Taxi might be the best option (you can walk back to the station once you know the way).