Cincinnati
Cincinnati Geography & Climate
Geography
Cincinnati sits in a basin on the north bank of the Ohio river, ringed by hills that rise a hundred metres or more above the water.
The basin
The original city occupied a flat terrace between the river and a semicircle of steep hillsides, which is why the downtown grid is compact and abruptly bounded. Nineteenth-century Cincinnati was one of the most densely built cities in America because it had nowhere to go, and it climbed the slopes with inclined-plane railways to reach the hilltops.
The hills
Mount Adams, Mount Auburn, Price Hill, Clifton and the rest are genuine hills of glacial till and shale, and the neighbourhoods on them are separate communities with their own business districts and their own views. The topography is the reason Cincinnati feels less like a grid city than its neighbours.
The Ohio river
Around 400 metres wide here and the border with Kentucky. It was the great highway west before the railways, which is why the city grew where it did, and it floods — the 1937 flood put the downtown under water and prompted the flood walls that now line both banks.
Glacial limit
The ice sheets stopped just south of here, which is why the land north of the river is rolling till and the Kentucky side is dissected, unglaciated and steeper.
Three states
The metropolitan area spills across Ohio, Kentucky and Indiana, and the Kentucky bank is close enough that Covington and its neighbours function as parts of the same city with different laws. The airport, the best view of the skyline and a good deal of the nightlife are all on the other side of the river, and crossing a state line is an unremarkable part of an evening here.
Fossils
The Ordovician limestone in the road cuts is among the richest fossil rock in the world.
Climate Patterns
Cincinnati has a humid continental climate with a distinctly southern edge to its summers.
Summer
June to August is hot and humid, with highs of 29 to 31°C and dew points that push the heat index well above that. The river valley traps moisture and air, and the basin holds heat, so downtown runs warmer than the hills around it. Thunderstorms are frequent and sometimes severe.
Winter
December to February is cold but not extreme: highs of 4 to 7°C and lows around minus 4°C, with around 55 centimetres of snow in an average year, generally in several modest falls rather than one large one. Ice storms are the more disruptive hazard.
Spring and autumn
Both are good and both are short. Autumn is the more reliable: warm, dry, clear, with colour on the hills through October. Spring brings rain and the possibility of severe weather — this is the eastern edge of the region where tornadoes occur.
Flooding
The Ohio rises substantially in late winter and spring; the 1937 flood reached nearly eighty feet at the gauge, and the flood walls date from after it.
The basin effect
Cold air drains off the hills into the basin on clear nights and warm air stagnates in it on still summer days, so downtown and the valley floor regularly differ from the hilltop neighbourhoods by several degrees in either direction. Fog forms readily along the river in autumn and spring.
Rainfall
Around 1,070 millimetres a year, spread fairly evenly across the months rather than concentrated in a wet season, with May and July usually the wettest. Snowfall averages around 55 centimetres, which is modest by Ohio standards — the city is far enough south and far enough from the lake to escape the worst of both.