Jacksonville sits on the St Johns River in northeastern Florida, near the Atlantic coast at approximately 30.33°N, 81.66°W. It has a humid subtropical climate (Köppen Cfa) — with long, hot, humid summers and mild winters — with a distinct summer wet season and exposure to Atlantic hurricanes.

Summer, from June to September, is long, hot and humid, with July and August the hottest — average highs around 33°C and sultry nights — tempered slightly by the sea breeze. Near-daily afternoon thunderstorms bring torrential rain, and this is the peak of the Atlantic hurricane season, when storms can strike the coast with wind and surge.

Winter, from December to February, is mild and dry, with January the coolest month — average highs around 19°C and lows near 6°C. Frost occurs on the coldest nights, but snow is essentially unknown. Humidity is much lower and rain much reduced, making this bright, mild stretch comfortably the pleasantest time of year.

Jacksonville receives around 1,300–1,350 mm of rain a year, strongly concentrated in the summer wet season from June to September, when thunderstorms and tropical systems deliver the bulk, while the winter and spring are markedly drier. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Jacksonville sits at the northern end of Florida's peninsula, where summer sea breezes converging from the Atlantic and the Gulf collide to trigger the daily thunderstorms that make Florida the lightning capital of the United States. Hurricanes remain the gravest threat, striking most often from August to October.

To follow any single measurement in Jacksonville more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.