The Weather Company (TWC) collects weather data across the globe at the rate of 34 million records per hour, and the TWC History on Demand application serves that historical weather data to users via an API, averaging 600,000 requests per day. Users are increasingly consuming large quantities of historical data to train analytics models, and require efficient asynchronous APIs in addition to existing synchronous ones which use ElasticSearch. We present our architecture for asynchronous data retrieval and explain how we use Spark together with leading edge technologies to achieve an order of magnitude cost reduction while at the same time boosting performance by several orders of magnitude and tripling weather data coverage from land only to global.