May want to check the weather. There is a storm heading into St. Lucia this weekend.

It does not get cool at night (well not for me) but some places have aircon so high that you do need something to cover your arms.
The beach at Reduit is really nice and has easy access for kids with clear water and light sand.
Excursions to the volcano at Soufriere, Diamond Falls botanical gardens might appeal to kids. Not sure if the Jolly Roger still sails the length of St Lucia, I took my daughter when she was little and she liked it.

The road from Rodney Bay right down to the south where the volcano is is rather windy so kids might get car sick.

Hopefully the storm would have passed by the weekend, but check Stormcarib for updates.

I prefer long sleeves and long pants in the evening, not because it gets cool (though there can be a breeze) but because of mosquitoes, which are a particular nuisance at sunset.

take a water taxi from rodney bay to soufriere. then catch another water taxi to anse chastenet a/or jalousie to snorkel from their beachw. both resorts have restaurants on the beach so you could get lunch

You can find some good info and suggestions here. Once you formulate a plan, then check back with members for confirmation. Have a good time on the Island.

http://uptodatestlucia.com/

Thde snorkeling is not very good around St. Lucia. If you take a snorkel tour boat they will take you to the few areas that have some healthy coral and fish but do not expect too much, unfortunately.

Thanks!

So far we have done the Pirate Adventure (fun for the kids, but rained most the day) and horseback riding. The pirate adventure included a trip to the falls/botanical gardens and volcano. On our last day (tomorrow), we are looking to drive to Anse Chastanet or Anse Cochon to snorkel/swim. Any recommendations for the logistics of getting there? Anse Chastenet is a little further. How do you access the beach? Through the resort? I understand Anse Cochon is accessed through Ti Kaye resort and there are lots of steps. Which beach is the nicest to hang out at especailly for the kids?

Anse Chastanet would be easier with kids. Best to avoid the steps at Ti Kaye as you would probably have to carry the 2 yr old.. or take all day!

Drive to Soufriere and then along the bumpy road to the resort.. walk through to the beach. They have a restaurant on the beach you can eat at which is nice.

It's a long day trip from Rodney Bay though!