average monthly temperatures st. augustine fl
St. Augustine Lighthouse and Keepers House. Â© Dawn Henthorn, licensed to About.com. St. Augustine, located in Northeast Florida, has an overall average high temperature of 78Â° and an average low of 61Â°. The highest recorded temperature in St. Augustine was 103Â° in 1986 and the lowest recorded temperature was a very 10Â° in 1985. On average St. Augusinte's warmest month is July and January is the average coolest month. The maximum average rainfall usually falls in September.