Ryanair offer travel insurance policies as an add on to a flight booking, or they can also be purchased as stand-alone products. Ryanair travel insurance is offered in two levels, so you can choose the option that's right for you and your wallet.
Jamaica's rainy season coincides with ours here in Florida (I am in the Tampa area) for the most part. We have anywhere from 30-50% chance of rain daily until hurricane season is over. I didn't mean you have rain every day, all day from May to December in Jamaica, but I assume it is a lot like here in Florida.
Jamaica Jazz & Blues Festival (Montego Bay, late January) Bob Marley Week (Kingston, late January-early February) Bob Marley Birthday Bash (Montego Bay, early February) April-June: Average temperatures are between the mid-70s and high 80s, but the weather can be a little rainy. Given the mist, the golf courses and beaches are relatively quiet, and hotels offer incentives to visit in spring.