Louisville sits on the Ohio River in northern Kentucky, in a broad river valley at approximately 38.25°N, 85.76°W. It has a humid subtropical climate (Köppen Cfa) — with hot, humid summers and cool winters — lying on the transition between the Midwest and the American South, and it is one of the more humid large cities.

Summer, from June to August, is hot and very humid, with July the warmest month — average highs around 31°C — and heatwaves that can exceed 35°C, made stifling by Gulf humidity trapped in the Ohio valley. It is the wettest season, with frequent afternoon thunderstorms and sultry, hazy days.

Winter, from December to February, is cool and often grey, with January the coolest month — average highs around 6°C and lows near -4°C. Snow falls, around 30 cm a year, but thaws are frequent, and the season swings between mild, damp Gulf air and sharp cold snaps, with freezing rain a recurring hazard.

Louisville receives around 1,150–1,200 mm of precipitation a year, spread through every month with a spring and summer maximum from thunderstorms; the Ohio River valley funnels and traps humid air, giving the city notably muggy summers. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Louisville's position in a broad bend of the Ohio valley traps warm, humid air, giving it summers muggier than most of the Midwest, while its location on the Canadian–Gulf air-mass boundary brings sharp winter swings and the freezing rain that periodically glazes the city.

To follow any single measurement in Louisville 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.