Last 5 Years in UK are .82C Colder Than Previous 5 Years

Last 5 Years in UK are .82C Colder Than Previous 5 Years. (Data from UK Met)

 

UK Met - UK - Tmean Anomaly

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UK May Tmax temperatures cooling at -.618C / decade for 15 years

Using data from the UK Met, May Tmax (mean maximum temperature) in the UK is cooling at -.618C / decade for 15 years.

The warmest May Tmax (in the last 104 years) was 16.9C in 1992. May 2013 was 13.8C. Tied for 33rd coldest out of 104.

CO2 seems to not work in May in the UK ….

May UK Met Last 15 Years - UK - Tmax Anomaly

 

UK Decembers Tmax Cooling -.45C/decade for 30 years and Sunshine is Up Too

Using UK Met data from here, I noticed that Tmax for Decembers are cooling at -.45C / decade for 30 years.  Thats a lot!

And then I wondered why? A theme I have returned to over and over is that hours of bright sunshine has increased because of cleaner air. Could more sunshine in December lead to cooler Decembers since clear skies can lead to colder temperatures in winter?

Guess what. Sunshine is up an average of 5.5 hours per year in December for the last 30 years. And compared to 1988 sunshine is up 80% in December. Instead of 28 hours of sunshine in December, the average is closer to 48.

Click on the graphs to enlarge.

Dec UK Met Last 30 Years - UK - Temp

 

Dec UK Met Last 30 Years - UK - Sunshine Hours

 

UK Tmax versus Sunshine are well correlated. Cleaner Air. More Sunshine.

This graph is Tmax % of normal versus Sunshine% of normal. The curved lines are the Loess curves from [R]. Data retrieved from here.

Why would sunshine be higher? Cleaner air in the UK (until China and India started to burn a lot more coal) thanks to the Clean Air Acts of 1956 and 1968.

The loess curves bottom out around 1968/1972.

UK Tmax vs Sunshine (Annual)_Tmax_Sunshine

 

 

UK Met Bright Sunshine 5 year averages plotted using all monthly anomalies

An addition to this post on 5 year averages using NOAA data. This time I am using UK Met Bright Sunshine data.

1) The current 5 year period has less bright sunshine than the previous 5 year period.

2) The previous 5 year period had no large negative anomalies, and no unusual positive anomalies, yet it was the most sunshine since 1929.

3) The period from 1988 to 2008 was the longest without a -50 hour anomaly.

4) The large negative anomalies are returning to normal.