Just how bad are the climate temperature databases?

We are told by Scientists® that the Science® is Settled.  Meanwhile, I've been complaining for almost ten years about the poor quality of the temperature databases that are used to reach that conclusion.  Now the first ever, systematic audit of the most important of the climate databases has been done (as a PhD thesis).  The results are worse than even I expected:

• The Hadley data is one of the most cited, most important databases for climate modeling, and thus for policies involving billions of dollars.
• McLean found freakishly improbable data, and systematic adjustment errors , large gaps where there is no data, location errors, Fahrenheit temperatures reported as Celsius, and spelling errors.
• Almost no quality control checks have been done: outliers that are obvious mistakes have not been corrected – one town in Columbia spent three months in 1978 at an average daily temperature of over 80 degrees C.  One town in Romania stepped out from summer in 1953 straight into a month of Spring at minus 46°C. These are supposedly “average” temperatures for a full month at a time. St Kitts, a Caribbean island, was recorded at 0°C for a whole month, and twice!
• Temperatures for the entire Southern Hemisphere in 1850 and for the next three years are calculated from just one site in Indonesia and some random ships.

I love how the average temperature of St. Kitts was freezing - so it must have been below freezing for half of the day.  And the highest recorded temperature in history was 58°C (Death Valley, July 10, 1913) - the 80°C (176°F) would have killed everyone in the town.

But shut up and pay up.  Because reasons.

Remember, this is the most prestigious temperature data set used today.  The IPCC relies on it for their regular reports.  Oh, and this is from the group that hid the decline:



I think that this is my first post (from 2009) criticizing the temperature data sets.  Interestingly, it touches on what Dr. Muller discusses in the video, and it was from 3 months before the ClimateGate revelations broke.