Is it warm, cold or just normal?

March 22, 2019 wansteadmeteo 1 Comment

Saying how warm or cold a day feels is subjective; one person’s hot day in spring is another’s ‘on the warm side’. Similarly when someone says the temperature on any given day is ‘normal for the time of year’ others will be exclaiming how cold they’re feeling.

The ‘heatwave’ in February was a case in point. Though many places recorded their warmest February maxima on record many were saying it was just a nice, warmer than normal spell of weather.

Some years ago the Met Office issued guidance on how warm or cold a day was relative to the anomaly. Earlier this month the table was posted on Twitter and I have plotted a graph for the spring period.

Today’s (March 22nd) maximum of 11.1C is therefore described as ‘normal’.

London weather, UK climatology, Weather

Data reveal windiest March for 4 years

March 20, 2019 wansteadmeteo Leave a comment

March 2019 has been a windy month so far. With 11 days to go it is already the windiest March for 4 years and the windiest month for over a year.

The windiest month recorded since 2013 was December 2015.

Looking at the data in general there seems to be a pattern of a windy month that is followed by a decline of between 10 and 13 months.

Gardening, London weather, trees, UK climatology, Weather

Spring or still winter? Plants reveal all.

March 11, 2019 wansteadmeteo Leave a comment

With the record warm spell last month and high sunshine totals you would think that the growing season is well under way. Spring bulbs have been out for weeks, trees are blossoming and many shrubs are on the verge of flushing.

But a look at the local temperature records over the last six years shows that things aren’t as advanced as previous seasons.

Considering the period from December 1st – in recent years a date when it is common to see bulb shoots beginning to emerge – to March 10th reveals the following table in terms of growing degree days.

The warm days of last month were cancelled out by cold, frosty nights, leading to little net warmth. And the last ‘growing degree-day’ was on March 2nd. Nevertheless growth is further on than last year that saw record cold in March.

The season is a long way behind 2015-16, however, which saw a record-breaking mild December.

Looking at the list below, and the at best average outlook, we’ve still got a way to go before we’ll see most trees in full leaf…

plant development — This list courtesy of Wikipedia

London weather, Weather

February’s record diurnal temperature ranges

March 6, 2019 wansteadmeteo Leave a comment

Last week’s warm spell not only saw national maxima records tumble but, locally, saw the February diurnal temperature range record shattered too.

Four days of near cloudless skies produced classic conditions whereby the maximum amount of solar heating by day was followed by clear nights allowing all that heat to escape with air frosts forming.

The spell saw five new entries in the ‘top 10’ of February diurnal temperatures since 1959, with both the 25th and 26th surpassing the record set in 1976 by at least 0.3C.

feb diurnal new — Top 10 February diurnal temp ranges

The diurnal ranges were not enough to make the annual list, however

top 10 diunrals — Top 10 diurnal temperature ranges since 1959

London weather, UK climatology, UK rainfall, Weather

Winter 2018/19: average with extremes

March 2, 2019 wansteadmeteo Leave a comment

The winter of 2018/19 will probably be remembered most for the remarkable warmth in the last week of February. And for its lack of snowfall.

Overall statistics for the season look fairly unremarkable.

The mean temperature finished 6.1C, that’s 0.7C above average, the mildest for 3 years.

Rainfall was below average: 127mm fell, that’s 87 per cent of average and the driest for two years.

Sunshine was well above average: 211.6 hrs is 126 per cent over average, the sunniest for seven years.

The warmest day of the winter occurred on December 30th with 14.2C recorded. The warmest night was on January 28th when the temperature fell to just 10.8C.
The wettest day of the winter occurred on January 2nd when 15.3mm was recorded.

Snow first fell on 5 days between January 22 and February 1st: five days of snow falling and two days of snow lying over the three months is below average.

There were 29 air frosts during the three months, seven above the 1981-2010 average.

A full weather diary is available for the months of December, January and February. To view full stats for each month follow this link:http://1drv.ms/1kiTuzv

Summary for period 01/12/2018 to 28/02/2019

Temperature (°C):

Mean (min+max) 6.1

Mean Minimum 2.6

Mean Maximum 9.7

Minimum -6.5 on 30/01/2019

Maximum 18.7 on 26/02/2019

Highest Minimum 11.5 on 06/12/2018

Lowest Maximum 1.3 on 23/01/2019

Air frosts 29

Rainfall (mm):

Total for period 127.0

Wettest day 11.4 on 20/12/2018

High rain rate 28.1 day 26/01/2019

Rain days 31

Dry days 59

Wind (mph):

Highest Gust 31.1 on 09/02/2019

Average Speed 2.8

Wind Run 6152.3 miles

Gale days 0

Pressure (mb):

Maximum 1043.8 on 02/01/2019

Minimum 980.4 on 01/12/2018

Days with snow falling 5

Days with snow lying at 0900 2

Total hours of sunshine 0.0

London weather, UK rainfall, Weather

February 2019: very mild and sunny

March 1, 2019 wansteadmeteo 5 Comments

February was most notable for how mild daytime temperatures were in comparison with night-time.

The 27th and 26th saw diurnal ranges of 19.4C and 19.3C respectively, the highest range recorded in any February since 1959, helped by huge temperature anomalies brought by the synoptic conditions. Although the UK maximun temperature record for February was broken with Kew Gardens reaching 21.2C the February TMax record in Wanstead, 19.7C set in 1998 remained intact.

The mean temperature finished 7C, 1.7C above average, the mildest February for 5 years.

Some 33.7mm of precipitation was recorded, 86 per cent of the 1981-2010 average, about the same as last year.

Some 124.6 hours of sunshine were recorded, that’s 170 per cent of average, the sunniest February for 11 years.

Ten air frosts were recorded.

There was one day where snow fell and one day of snow lying, 1cm on 1st.

To view full stats follow this link:http://1drv.ms/1kiTuzv