NOAA NWS - Costa Rica Weather - US government site provides hour-by-hour weather conditions for the past 24 hours for major cities and locations in the country. - http://weather.noaa.gov/weather/CR_cc.html
Weather Underground - Costa Rica - Displays current conditions for all major cities on one page, with five-day forecast and more detailed information for each available. - http://www.wunderground.com/global/CS.html
BBC Weather Centre - Country Guides: Costa Rica - Provides climate and weather information, facts and statistics about the country, along with five-day forecasts for major cities. - http://www.bbc.co.uk/weather/world/country_guides/results.shtml?tt=TT001810
Weather.com - Costa Rica - City-by-city weather reports and forecasts. - http://www.weather.com/common/drilldown/CS.html