well the rainy season has already begun and with a bang, mind you. We had many days of rain, rain , rain. ( this was a combination of a storm and rainy season). The typical rainy season is lots and lots of rain, thunder and lightening at night or late afternoon, sometimes cloudy in am with left over rain, early morning, then clearing and sun, but all of Mexico this year has had non-typical weather...Jan/Feb. were exceptionally cold etc...anyway it will be humid, yes that is a given....it will rain, also a given but hopefully at night...you have AC at Velas....pools, great food , entertainment etc. etc...
Personally I live in a drier , higher elevation in Mexico but when I go to beach I want hot....and sun....and no rain, but I do go in July, am scheduled this July as well, and yes it will rain at times, but PV is fascinating no matter the weather, swimming with dolphins is awesome, and the trip to Las Caletas, well if weather calm, then okay, otherwise I might skip that or only do in daytime.
I am hoping for all of us that the typical rainy season prevails...today it was sunny till early eve....no rain as yet...
Just have your relatives think it will rain and go for it, let them know will be humid and go with that....they will surely have a great time anyway......
I have never found it to be unbearable.....especially when you can go in A/C, go swimming, etc. Some days might be tough to shop with humidity but Pv is great they will love it, and if it rains well they may experience some things they have never such as tremendous lightning shows, thunder, street flooding with happy mexican children playing in rain.....do not worry they will have fun....Now mind you I hate rainy season, but who can control the weather, so just tell them to enjoy!!!