Tag Archives: London rainfall

Wanstead weather: October 2023

The mean for this October finished 13.1C, 1.3C above average. That’s 15th warmest locally since 1797 and 0.6C down on last year! Notable given the start was nearly 6C above average.

Rainfall finished 96mm, 144% of average. Which sounds a lot. But considering the last 5 years it would be third wettest – such is that October now seems to be a default wet month. Back to 1797 it would place 47th.

Looking at the average 9am pressure things really went south after the 17th.

Looking at London as a whole rainfall at this Wanstead station was closer to the total at St James’s Park than Redbridge Roundabout!

And further afield check out how much wetter the south coast was.

Maps courtesy of Starlings Roost Weather.

Wanstead’s rainfall: swinging from dry to wet

Tracking the rolling 12-month daily rainfall total allows a ‘real-time’ look whether an area is experiencing a drought or a deluge.

This week’s figure represents the 8th highest at this date since 1962. So not unusual. Until you look at the jump since last year. Some 303.6mm the past 12-months just pips the same period in 1976-77.

What is perhaps most noticeable is that this year follows last year’s negative fall which was the largest since 1961.

It’s one rainfall station BUT the results suggest a climate that is swinging more violently from one extreme to the other.

London droughts back to 1871 (2022 update)

Since I wrote the original blog on London droughts in July 2018 there have been five more meteorological droughts.

The latest, as I write this on August 8th 2022, now sits joint 2nd in longest droughts in this area.

The rolling 12-month rainfall total has now reduced to 457mm; the lowest since 2017, and low given that the annual Jan-Dec rainfall average here is 602mm. At this point last year the rolling 12-month total was 818mm!

Looking further back, at a monthly rainfall series that goes back to 1797, the opening seven months of this 2022 are the 6th driest.

Whatever way you look at it this area is desperate for rain.

Where’s east London’s rain coming from?

April 2019 was yet another dry month. Just under 12mm was recorded, that’s 28 per cent of average.

There has been rain around but the prevailing wind has not been conducive for great amounts to fall here. Last weekend, over a period of 5 days, just 0.9mm fall. Yet Capel Curig in Snowdonia, 200 miles northwest as the crow flies, recorded 130mm thanks to a NW’ly regime.

A look at rainfall in Wanstead back to July 2013 shows that of the 3,550mm recorded just 17 per cent has fallen when the wind was NW’ly.

Because of the topography of the area most of our rain falls when the wind is blowing between SE’ly and SW’ly, a total of 43 per cent.

A westerly is usually reliable for rainfall, however because this area is in the lee of high ground areas such as Hampstead westerlies have delivered just under 8 per cent of that 6-year total.

rain rose