Weather in April 2021


Looking back on Aprils weather in the UK and around the world. April in the UK is normally known for its showers. But this year it was entirely different. Record amounts of frost occurred across the country. A nightmare for farmers and gardeners alike. It was also very dry, record-breakingly dry. Some places had less than 1mm of rain when April is usually one of the wettest months of the year. The temperatures were suppressed during the day although it felt warm in the sunshine you needed to wrap up warm in the shade. At night it went below zero centigrade. It was the coldest minimum temperatures for April in England since records began in 1659! It was also the sunniest on record.

At the beginning of the month it was crazy weather with snow quite wildly and frosts galore. There were more frosts in April than we had in the whole of winter 2019- 2020. A few cold weather records were broken and this is fairly unusual in a warming climate.

The CET (Central England Temperature) came out at 6.4c which was -1.5c below the long term average.

Spring flowers in Greenwich Park, London

UK Stats

It was a cold month over the whole UK with predominantly northerly/easterly winds. It was also a very dry month with hardly any rain over a wide area of the UK and any precipitation that did fall fell as snow.

On the 1st a maximum temperature of 21.4 °C was recorded at Treknow (Cornwall).  -9.4 °C was the minimum recorded on the 12th at Tulloch Bridge (Inverness-shire).  28.8 mm of rain fell at St Athan (South Glamorgan) on the 28th.  The highest wind gust was 75 mph at Fair Isle (Shetland) on the 5th.  An amazing snow depth of 12 cm was recorded on the 7th at Loch Glascarnoch (Ross & Cromarty).

The frosts have damaged a lot of crops from fruit growers and has held back the growing season in most areas of the UK. You could see everywhere the Magnolia trees were scorched from the frost, for the fruit there will be a much lower crop this year.

People enjoying the sunshine in Greenwich Park, London

Watford Stats

The stand out statistic for April in Watford was the 10 air frosts. There wasn’t even 10 for the whole of last winter (2019-2020). There were also 28 dry days with a maximum rainfall of 1.2mm this was the driest April I have recorded in Watford since 1982. Amazingly there were 3 days when snow fell but nothing settled for long.

There was a maximum of 20.4c on the 19th and the lowest temperature of -2.9c on the 6th. The wettest day occurred on the 28 with 0.9mm of rain. My anemometer broke halfway through the month so wind speeds can be ignored.

Spring sunshine in Cassiobury Park, Watford

Around the world in April

Across the world, the temperatures were 0.19c above the long term average (1991 – 2020). This was 0.3c below the warmest April’s on record (2016 & 2020). Across Europe it was the coldest April since 2003, it ended up -0.9c below the long term average (1991 – 2020).

April was the world’s ninth-warmest April in 142 years of record keeping according to NOAA.

Some other weather-related stories occurred from around the world.
France : French vineyards devastated by April frost that followed unusually warm March
Philippines : Strongest tropical cyclone ever recorded for April hits Pacific
Mongolia, China : Huge sandstorm engulfs towns in China
Alabama, USA : Tornadoes leave trail of destruction and death in Alabama

Looking ahead to May in the UK

May is looking like another below-average month by temperature. A repeat of the previous months with outbreaks of northerly winds. Even at this time of the year, they can be potent.

Potential cold northerly winds bringing snow | Source: TheweatherOutlook

Summary for April 2021 in Watford

Temperature (°C):
Mean (1 minute) 7.2
Mean (min+max) 7.8
Mean Minimum 1.2
Mean Maximum 14.4
Minimum -2.9 on 06/04/2021
Maximum 20.4 on 19/04/2021
Highest Minimum 5.5 on 27/04/2021
Lowest Maximum 7.8 on 07/04/2021
Air frosts 10

Rainfall (mm):
Total for period 1.2
Wettest day 0.9 on 28/04/2021
High rain rate 7.2 day 28/04/2021
Rain days 2
Dry days 28

Wind (mph):
Highest Gust 10.7 on 04/04/2021
Average Speed 0.0
Wind Run 0.5 miles
Gale days 0

Pressure (mb):
Maximum 1021.2 on 22/04/2021
Minimum 983.7 on 21/04/2021

Days with snow falling 3
Days with snow lying at 0900 0

wrapping up warm in the spring sunshine in Greenwich

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Met Office –
Met Office Summary –
World Climate Data –
Real-time Watford Weather –
Flickr Spring Photos –
Weather Outlook –
March –

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