Radley has a modest flood risk, and rain is where it comes from. The river's official flood zones don't touch the village at all. Even so, about one postcode in eleven is flagged at high risk on some measure. There's no record of flooding here, and the nearest place that measures sea level is a long way off. You don't have to worry about the Thames, but a few of the drains are another matter.
None of Radley's postcodes fall in the Environment Agency's river-and-sea Flood Zone 3, the highest-probability band, and none fall in Flood Zone 2, the medium-probability band beyond it. Lower Radley is the part of the parish next to the Thames, and the river flood zones still don't reach any postcode this page covers. If an advert says "not in a flood zone", that's true here. It just doesn't cover rain.
The risk that does exist comes from surface water, meaning heavy rain that runs off faster than the ground and drains can take it. It's patchy and goes street by street, and the measures that pick it up are separate from the river zones above. Look up the exact address on the Environment Agency's long-term flood risk service and switch to the surface-water layer. The village-wide picture won't tell you which side of the road gets the puddle.
The Environment Agency's climate-adjusted flood zone, which models how the river-and-sea picture shifts with a changing climate, also covers 0% of Radley's postcodes. That's a modelled scenario, so it describes the river map under assumptions and says nothing about any particular downpour.
For insurance, a home outside the river flood zones with no recorded flooding should be easy to cover on ordinary terms. Houses on the handful of postcodes with a surface-water flag may get more questions from an insurer. Getting a quote on the exact address early in the purchase is cheaper than finding out after exchange.
Taking every measure together, 9% of Radley's postcodes rate high on at least one flood indicator, 7% rate medium and 30% rate low. Those shares count a postcode if any one of several measures flags it, surface water included, which is why they're higher than the river-zone figures. Most of the village isn't flagged by anything.
The Environment Agency's modelled flood extents put 0% of Radley's postcodes in the high-risk area, with or without defences in the model. So the defence question mostly doesn't come up here. Where a model does count a defence, that means a structure is present, and structures can be overtopped or neglected.
The nearest tide gauge to Radley is at Portsmouth, which recorded sea level rising by about 2 millimetres a year between 1962 and 2023. That's a past rate at a gauge on the south coast. When your nearest tide gauge is in another county, the sea probably isn't your main worry.
Environment Agency records show no historic flooding in the Radley area. That's real reassurance about its history, though the records only cover what someone wrote down, and they can't tell you about next winter.
On flooding, Radley comes out middling. The river leaves it alone, and the risk that remains is surface water on a minority of postcodes, which you check one address at a time.