On Thu, 31 Dec 2015 03:08:20 -0800 (PST), David Mitchell
wrote:

I referred to the 0900 recording time in a previous thread and really believe it's time to change.

Why? It's quite likely that quite a few sites will record there lowest temperature of December tonight, which in fact will not even happen on the same day, let alone in the same month or even in the same year.

For some, in some ways, it spoils a record breaking month.

I get the arguments for comparison purposes, but does it really make sense?

It does make sense if you use manual instrumentation rather than electronic. In
particular, the rain gauges in automatic weather stations, such as the various
Davis instruments, are a bit flaky. I find that mine under-reads by a variable
factor, usually in the range 10-20%, compared to what I measure with a standard
5" manual gauge.

If you use the standard 09z-09z recording period tonight's minimum temperature
will be credited to 1st Jan. As far as the daily minimum temperature is
concerned December ended at 0900z today. For the daily maximum temperature
December ends at 0900z tomorrow.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org