Mean Data for Cumulus NOAA Style Reports

[scramblers]

While searching for Normal Mean Temp and Normal Precipitation values to use in setting up my NOAA reports I came across the Met Office website which seems to contain all the info.

http://www.metoffice.gov.uk/climate/uk/datasets/#

I duly downloaded the Midlands figures and then used Excel to produce the average of 100 years of data. These figures I now use for my NOAA style reports.

Query! I seem to remember from my school days (50 years ago) that you can't (shouldn't) average means. I can't remember why? Are these figures valid?

[RayProudfoot]

Hi John,

I wouldn't use data that covers the whole Midlands area. Try to find data for an official station closest to your home.

Try this http://www.metoffice.gov.uk/climate/uk/ ... /19712000/

I chose Manchester Airport - 3 miles away. You may be able to find a suitable site for your location.

[b.e.wilson]

Funny, I was working on this just today. Here is where I got my US data:

State-wide means: http://www.ncdc.noaa.gov/oa/climate/res ... state.html
Selected city means: http://www.ncdc.noaa.gov/oa/climate/res ... /city.html

There must be something like this for the city I'm in, but I never found it. I have GIS data, but not a nice plot like this page makes, with averages and trends.

Anyway, to answer the original question, I can't see why you shouldn't average the monthly means, as they are displaced in time and the "bins" are roughly the same size. You certainly can't trust the error figure generated by averaging means. It might be better to do a least-squares fit of the trend, and use the most recent value of the trend line as the normal temperature and precipitation for your area. Right or wrong, that's what I'm doing.

[scramblers]

Solved the problem, quite easy really, just emailed the Met Office and asked them for the average monthly temperature and rainfall for Tamworth.

Yesterday I received the 30-year (1971-2000) monthly averages for their Coleshill station, their nearest station to Tamworth, it's about 11 miles due south. It's interesting to note that these averages are not on the Met Office website. The nearest I could find on their website was Sutton Bonnington which is about 22 miles north-east of Tamworth. The differences between the two sets of figures are quite interesting especially the rainfall.

Sutton Bonnington is only 30 miles north-east of Coleshill !!

[beteljuice]

They replied .... and gave you information for FREE

Times are a changin'

[scramblers]

The Met Office have emailed the following as way of an explanation:

Coleshill receives more rainfall per annual than Sutton Bonnington mainly due to its topography. Coleshill, altitude 96 metres AMSL, sits on a plateau which also contains the great West Midlands conurbation of Birmingham and the Black Country. Whereas, Sutton Bonnington, altitude 43 metres AMSL, is located in the Wolds of the East Midlands. Higher ground tends to receive more rainfall than low-lying areas as the attached annual rainfall average maps testifies.