Rain review

fkloodA car submerged in floodwater on the A406, near Charlie Brown’s Roundabout, on 25 July

Flash flooding this summer brought a taste of the world climate crisis to Wanstead and South Woodford. Local weather enthusiast Scott Whitehead offers his insights

Downpours at the end of July caused chaos around Wanstead and South Woodford and the wider Redbridge area, with homes and public infrastructure flooded.

Although the rain wasn’t unprecedented here, it was still notable in that the fall on Sunday 25 July was the greatest July fall ever recorded here and the fourth greatest of any month since 1960, measuring 48.5mm that day. The greatest rainfall ever experienced here was on 22 June 2016 (60.8mm), followed by 55.4mm on 20 September 1973.

The maximum rate I recorded at my weather station in Aldersbrook that day was 92.7mm per hour, the highest since I started recording in 2011.

The rainfall was the result of a convergence line over the area. Wherever these features set up, they always end with a deluge.

There was a big clear-up that evening and into the next morning as flooded cellars had to be pumped out. One person I spoke to in Leytonstone said the depth in her cellar was almost up to the top of a pair of standard wellies. She said the road outside was like a river and that another 30 minutes of that type of rain would have seen it overtop the front door. She said it hasn’t been that bad since August 2004. Her account mirrors many in Wanstead and South Woodford, particularly places like Hermon Hill, a large part of which sits in a dip, drains for which are often overwhelmed during sustained heavy rainfall, blocked or not.

The wet theme continued on until the first couple of weeks of August – accumulated rainfall so far this summer is currently just under 244mm, making it the third wettest summer on record. The wettest was in 1987 (269.8mm), with 1985 the second (249.6mm).

While this summer’s weather is not unprecedented locally, these extreme events seem to be occurring far more often than previously. Authorities must bear this in mind when it comes to maintaining and planning infrastructure.

Despite all the rain, the average mean temperature for this summer, up to mid-August, is still nearly a degree above average. Though I have recorded only three instances of 30ºC, the lowest since 2015, our modern climate is still as warm as ever.

Is summer over? Although August did, at times, feel autumnal, there is still plenty of time for warm, sunny weather. September can often be an extension of summer with high pressure being dominant; any wet breakdowns from the Atlantic are often brief.

For more of Scott’s ‘meteorology-based musings about east London’, visit wansteadmeteo.com

Author: Editor