Baton Rouge, the capital of Louisiana, sits on the Mississippi River in the southeast of the state, on low ground upstream of New Orleans at approximately 30.45°N, 91.19°W. It has a humid subtropical climate (Köppen Cfa) — with long, hot, oppressively humid summers and mild winters — and it is among the wettest American cities.

Summer, from May to September, is long, hot and oppressively humid, with July and August the hottest — average highs around 33–34°C — and the heat index regularly exceeding 43°C. Near-daily afternoon thunderstorms bring torrential rain, and this season coincides with the Atlantic hurricane season, when Gulf storms can strike inland.

Winter, from December to February, is mild and short, with January the coolest month — average highs around 17°C and lows near 5°C. Frost occurs on the coldest nights and snow is very rare. Cold fronts bring brief chilly, rainy spells alternating with warm, humid days; the season is comfortably the pleasantest of the year.

Baton Rouge is very wet, receiving around 1,550–1,600 mm of rain a year, spread through every month with a summer maximum from thunderstorms; the catastrophic flood of August 2016, when a stalled storm dropped over 500 mm in days, showed how extreme the rainfall can become. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Baton Rouge's flat, low-lying terrain drains poorly, so its torrential Gulf rainfall can accumulate catastrophically — the August 2016 flood, caused by a slow-moving unnamed storm rather than a hurricane, inundated tens of thousands of homes and was among the worst US flood disasters outside a named storm.

To follow any single measurement in Baton Rouge 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.