I was in Costa Rica in Jan 2015 on both coasts but in the south. Plenty of waves but no wind.
Apparently the only place to go kiting in CR is up in Guanacaste Province. Where the wind blows in from the Pacific and is funneled in from a break in the volcano ranges that lets it blow towards lago Nicaragua. I emailed a few kite schools there and they responded saying the wind at that time of year is between 30 - 40kts, every day! Didnt ask about waves. Anyway sadly I never made it there as the missus doesn't kite, but hope it make it back there one day. One of my favourite countries on the planet. Pura Vida!