Did NASA Fake the UK Temperatures?

The latest figures for global temperatures from NASA - GISS Surface Temperature Analysis are out, and they show July 2015 was the warmest July in the series, at 0.75C above the 1951 - 1980 base average. (Note, these figures generally change slightly as revisions are made.)
This, of course, will bring out the usual complaints that these figures are being manipulated, but I've also seen a couple of tweets making a specific point about the figures in relation to northern Europe, and specifically the UK.

Warmest July on record nnnly? Hum, I'm 100% sure this is NOT how July 2015 turned out for UK! pic.twitter.com/bD7UGKcYiM

— MarkVoganWeather.com (@MarkVogan) August 15, 2015

and

How GISS said July was over NW Europe. Seriously. Seriously!?!? pic.twitter.com/XenDY0GOlI

— Craig M (@CraigM350) August 14, 2015

Mark Vogan, recently featured on the BBC radio program What's the Point of the Met Office, also has a blog about it called July Warmest On Record Globally? UK And USA Not As Warm As They’d Have You Believe!, but the main part of his argument is behind a paywall. Though the free part suggests the direction he's coming from -

With the strong El Nino well underway, let's face it. Those on the global warming side of the argument need to push the warmth since this is the primary way to drive up global temperature. Oh wait, we've a strong El Nino comparable to 97-98, perhaps even more prolific given how warm the PDO is and we're not seeing global warming? That can't be... We need our government grand money.

At first glance this does seem curious. The UK is shown as being warm, 1 - 2 degrees above average in parts, whilst anyone who lives here knows it has been a disappointing summer. In fact, although July started on a short heatwave, with record July temperatures in many parts on the 1st, it soon cooled down and finished up below average. The Met Office puts the UK at 0.7 C below average, with Scotland being colder and only East Anglia being slightly above average.
The GISS map is showing the UK as being warm,
So why the discrepancy? Has NASA been found out in yet another hoax? Of course not. It doesn't take much effort to figure out what the problem is. The GISS website allows you to try out different mapping options, and I think this discrepancy is down to two factors.

Default Settings

Here is the map you get by selecting the default options

Global Temperatures

and zooming in on the UK

Global Temperatures

This appears to be the map used by Mark Vogan and CraigM350 above.

Changing the Smoothing

The default map uses a smoothing algorithm that blurs out the temperature anomalies. This produces a more attractive map, that makes it easier to see the broad global patterns, at the expense of not showing accurate temperatures in specific locations. By default each temperature reading has a smoothing radius 1200 km, so the UK on the map is being influenced by the very hot weather in parts of Europe. European temperatures are being reduced slightly by the cooler weather in the UK and other parts of Europe.
Setting the smoothing radius to 250 km gives us this map.

The UK is cooler, but still above average, whilst central Europe is now very warm.

Changing the Base

But the UK is still above average when it should be below average.
But what average are we using? The default GISS map is using 1951 - 1980 as the base for the average. This is the same period they use for all their anomalies. But the figures I quoted for the Met Office, which can be found here are those for the 1981 - 2010 average. The Met Office also give figures compared against the the 1961 - 1990 base period (closer to the GISS base) and these show JULY as being only slightly below average, with much of England being above average. East Anglia is 1 degree above average.
This demonstrates how important it is to compare anomalies against the same base period. Decade by decade temperatures have been getting warmer.
We can easily get a fair comparison by entering the 1981 - 2010 base period into the GISS dialogue.

This shows the UK as being below average just as the Met Office figures say.

Conclusion

There's no discrepancy between GISS's and the Met Office figures. Comparing like for like both show the UK was below average compared to recent years, but above average compared to temperatures before global warming kicked in.