Am planning a trip starting mid may till mid july starting in panama going overlandby bus finishing in mexico. route as planned so far is panama, costa rica (for a few nights only), nicaragua, guatemala and mexico (and time permitting belize but still unsure). Not to sound vain but do want to get a good tan out there and also in terms of activities would like to get a good idea of what weather to expect. Could anyone help? Would be much appreciated.