Columbus
Columbus Geography & Climate
Geography
Columbus sits in the centre of Ohio where the Olentangy river joins the Scioto, on flat glaciated plain about 275 metres above sea level.
Flat and central
The site was chosen in 1812 precisely because it was central and undeveloped — a capital was to be built on empty ground rather than at an existing town. The land is glacial till, level and fertile, with no natural obstacle in any direction, which is why the city has been able to sprawl so freely and why its growth has not been constrained the way Cincinnati’s or Pittsburgh’s was.
The rivers
The Scioto runs south through the middle of the city to the Ohio, joined downtown by the Olentangy. Neither is navigable for anything larger than a canoe, so unlike the river cities of the Ohio valley, Columbus was never a port — its early growth came from being the seat of government and then from the National Road and the railways.
The restored channel
The Scioto downtown had been dammed into a wide, shallow, stagnant pool. Between 2013 and 2015 the dam was removed, the channel narrowed and thirty-odd acres of riverside parkland created, restoring flow and habitat through the centre of the city.
Flooding
Franklinton, on the west bank, flooded catastrophically in 1913 and was protected by a floodwall only in the 1990s.
Annexation and shape
The city’s boundary on a map is extraordinary — a jagged shape with islands of other municipalities inside it, produced by fifty years of annexing land parcel by parcel in exchange for water and sewer service. It is why the city covers over 560 square kilometres and why its suburbs are interleaved with it rather than ringed around it.
Glacial edge
The ice sheets reached just south of here, and the land becomes hillier immediately below the city.
Climate Patterns
Columbus has a humid continental climate in the middle of Ohio, without the lake or river effects that modify the state’s other cities.
Summer
June to August is warm to hot and humid, with highs of 28 to 30°C and nights around 18°C. Thunderstorms are frequent, often in the late afternoon, and can be severe. The flatness means there is nowhere cooler nearby to escape to.
Winter
December to February is cold: highs of 3 to 5°C and lows around minus 5°C, with about 70 centimetres of snow in an average year spread across many small falls. Columbus is far enough from Lake Erie to avoid the lake-effect snowbelt that buries the north-east of the state, which is one of the practical advantages of its position.
Cloud
Ohio winters are grey. December and January average very few genuinely sunny days, and the overcast is what residents find wearing.
Spring and autumn
Autumn is reliably good — warm, dry and clear into late October. Spring is wet and volatile, and April and May are the peak of severe weather season, with tornado watches a normal part of the calendar.
Heat island
Flat ground, low density and a great deal of asphalt mean Columbus runs several degrees warmer than the surrounding farmland at night in summer, and the effect is most noticeable downtown and along the ring-road corridors. Tree planting programmes in the older neighbourhoods are a direct response.
Rainfall
Around 1,000 millimetres a year, distributed fairly evenly across the months with a modest peak in late spring and early summer when thunderstorms are most frequent. There is no dry season, and long settled spells are uncommon in any month except September and October.