Today being a perfect example of the month sat in the garden with a beer.  Warm in the sunshine.  Actual temp only 11c though.

Looks like the coldest April on record that was so dry. 

APRIL 2021   Metcheck     6.8c.

                    Netweather  6.28c. Anomaly -1.23c. 

Hadley has it down as 6.4C

But the truly amazing figure is the minimum, it has it as 1.0C and therefore coldest since at least 1878

https://hadleyserver.metoffice.gov.uk/hadcet/mly_cet_min_sort.txt

Wow! The coldest April minimum CET on record then.

For all the cold weather lovers on here April has been an epic month for cold and very noteworthy.

Difference between max and min is 10.8°C. This is the 4th biggest range for April, but follows on from the 2nd biggest range in 2020. Oddly, the 1st and 3rd biggest ranges where also consecutive years.

Year   Max   Min  Range
1893   16.5  4.0   12.5
2020   16.1  4.7   11.4
1892   12.9  1.7   11.2
2021   11.8  1.0   10.8

And not by a small amount, previous coldest was 1917 at 1.4°C. There hasn't been a min below 2°C for almost 100 years.

5.3C was the final mean here making it the coldest since 1986 with 1951, 1966 and 1983 the only other post-war Aprils to be colder.

Mainly down to the mean min of 0.7C being likely cooler than even 1917 and 1922 with a record breaking 14 air frosts.

Mean max was 9.9C which was 1C below average but both 2012 and 2016 were significantly colder.

As well as 2012 and 2016, the first 13 days of April 2013, the first week and final third of April 2014, the second half of April 2017 and the first halves of the Aprils of 2018 and 2019 were all worse than anything April 2021 produced.

Plenty of rubbish cold dismal April weather in the past decade which is why the mean for that period is lower than the 1981-10 average and the total of three sub-6C April more than there were even in the 1960s when only 1966 and 1969 came in below 6C. There weren't any sub-6C Aprils between 1990 and 2011.

All of the three lowest April maximums in 80 years of records at Dyce have now occurred in the 21st Century

2001: 13.1C

2012: 13.2C

2021: 13.5C

1951: 13.9C

1972: 14.0C

Only one year in 60 failed to reach 14C. Now we've had three in 21 years. Just shows how harder it is to achieve any warmth in these hideous days of relentless onshore breezes . 

There wasn't a single April in the 1960s that failed to reach 15C. The lowest maximum was 15.6C in 1960. All the others reached at least 16.6C. Since 2006 the following April's have recorded a lower absolute maximum than the worst performing year of the 1960s: 2006, 2009, 2012, 2014, 2016, 2021.

Quite clear that the 1960s is no longer the benchmark for bleak, chilly dross where even moderate levels of warmth struggle to be achieved. The current era blows it out of the water in that respect 

That's an impressive feat and no doubt down to the prevalance of clear skies, light winds (from high pressure) and being north of the jet with Arctic (or modified Arctic) airmasses for most of the month.

It goes to show that despite the fiery August-strength sun by day, cold temperatures are still very much possible by night!

No air frosts here for a while now but even so the minimas have been noteworthy, 2 or 3C being very common this month. A little bit further inland a white frost - if you're up early enough! - has been commonplace.

Despite it only really being flurries rather than anything more, there have been the most days of snow falling here (3) in April since the 80s.

An impressive month for cold. The coldest April since 1986 and the coldest April for minimum temperatures since the 19th Century. Also, one of those occurrences where April is colder than the preceding March, which last happened in 2012 I believe.

A weather station at Amanda Owen's farm in Ravenseat has recorded 27 air frosts through April and the mean minimum for the month was -3.8C
https://www.wunderground.com/dashboard/pws/IRICHM64/graph/2021-04-30/2021-04-30/monthly

April was a real freak month, and goes to show that monthly variability in a rapidly warming climate is still capable of producing some notable cold anomalies, however fleeting against the background pattern.

My concern is that locally a weaker jet and melting ice from Greenland may conspire to bring a cluster of such events over the next decades.

That would be very interesting in winter, but less fun in spring.

Top 30 driest Aprils on record with their CETs

1938: 7.6  (7.1mm)

1817: 7.6  (7.9mm)

1912: 8.8 (9.0mm)

1957: 8.9  (9.7mm)

1893: 10.3 (9.9mm)

1785: 8.4  (10.1mm)

2007: 11.2 (10.4mm)

1984: 8.1 (10.8mm)

2011: 11.8 (11.6mm)

2020: 6.4C (~14mm)

1854: 9.2  (14.1mm)

1842: 7.8 (14.3mm)

1974: 8.2 (14.3mm)

1783: 10.1 (15.2mm)

1954: 7.6  (16.1mm)

1844: 9.8  (16.6mm)

1980: 8.8  (17.5mm)

1976: 8.1  (19.0mm)

1855: 7.1  (19.9mm)

2017: 8.9  (19.9mm)

1852: 8.2  (20.1mm)

1870: 9.2  (21.5mm)

1801: 8.3  (21.6mm)

1776: 9.4  (22.4mm)

1807: 7.7  (22.9mm)

1778: 8.2  (23.0mm)

1873: 7.7  (23.1mm)

1997: 9.0  (23.7mm)

1840: 9.7  (24.2mm)

1982: 8.6 (25.4mm)

1806: 6.8 (26.8mm)

Coldest April ever recorded that was so dry combining the 1766 rainfall series with the 1659 CET series

If you detrend the Monthly Minimum CET for April 1878-2021 to take out the background warming of about 1C over that period the freakiness of the April 2021 data becomes even more clear. It has the lowest value of any April minimum by over 1C on that basis

Here are the charts for April and Spring to date

Chart 1

Chart 2

Chart 3

Chart 4

Chart 5

Chart 6

Annual CET competition - April update

Some large errors for everyone this month but Frank H retains a comfortable lead.

Direct link to larger version of table

Wow, out of the carnage of this month's predictions, I suddenly find myself in 2nd place!

I'll take a jump up to fourth as well!

Well done Frank H!      I’m surprised I’ve stayed in the top ten!  

Yeah, same - in fact, I've stayed in the same position, which is madness.

The bunching now, though is brilliant!

I suspect a lot of movement come the end of May.

Thanks for the speedy update, too, GW