CHRONOLOGY
1998 (25th October): first weather notes from this site [ after
moving from St. Albans, Hertfordshire in September that year.] Only
non-instrumental observations available.
1999 (17th June): first temperature readings using 'Sixes' max/min set.
1999 (31st October): certified thermometers in use.
1999 (November): First month of 'full' readings at this site, but using
a screen that was deteriorating, and which was highly 'non-standard' in that it
did not have double-louver construction. (See HERE)
for more details.
2002 (8th August): Maximum thermometer failed and we were having
problems with minimum instrument as well at this time. As we couldn't afford to
replace either, temperatures taken with 'Sixes' as above .. known to read at
least 1degC high when in the 20's degC, and as much as 2degC high when
approaching 30degC. (but now see note at 2006 below)
2002 (17th October): Long before the failure above, I had started
re-building the screen - new/refurbished screen in use at this date (but with
sub-standard instrumentation), and in same location .. i.e. north-facing wall
of garage (spaced away from).
2003 (4th August): Managed to convince myself that I could afford a full
set of certified thermometers, and these brought into use at this date, just in
time for the hottest days of modern times! [details: Ordinary
85644/Casella; Minimum (screen) 03454/Metcheck; Maximum (screen)
03451/Metcheck; Minimum (grass) 99863/Metcheck.]
2004 (1st January): Two readings now taken daily - one (as before) at
0900 and another at 1800 GMT.
2006 (May): Have produced some better mean 24hr maxima, minima and day
mean figures for the period from August 2002 to July 2003 when my maximum
thermometer failed (see above); these are now uploaded onto the web site.
2006 (August): Replacement mercury-in-glass thermometer (06095/Metcheck)
brought into use at 0900Z, 1st August, to replace previous (03451/Metcheck)
which I suspected may be playing up, though in reality, may have been OK.
INSTRUMENTATION
Thermometers: From 1999 until early August
2002 certified mercury-in-glass. 'Garden-Centre' "Sixes" max/min
early August 2002 to early August 2003. Then back to (new set) of mercury (or
alcohol) in glass thermometers. These mounted in a Stevenson-pattern
screen, this in turn mounted in a north-facing situation on the end
of the garage, but with a 30 cm gap between the screen and the garage wall.
(See history for details of changing screen).
Rain gauge: a "5-inch" gauge - copper- mounted with rim circa 30 cm above the ground - on a small slab (no splash from this, but in very heavy rain, splash from adjacent path may be a factor). Note that this gauge does not have the 'fluted' top to catch large quantities of hail/snow, so some loss possible in these situations. Also available (for checking purposes), a plastic ' all in one ' type, with aperture 8cm (just over 3 inches), also mounted with lip circa 30 cm above ground level. None of the 'standard' conditions for rain-gauge mounting can be met in our small garden, so 'catch' will be considerably affected by obstacle eddies, particularly with a wind from a southerly direction. In addition, there is a low wall to the north of the gauge. However, I have checked our readings over a period of several months with those from the Met.Office site less than 2 km away at Beaufort Park, and the readings are not wildly in error. For an analysis, see: HERE
OBSERVING TIMES
Readings are now (2004) taken at 0900 UTC AND 1800 UTC, either by myself, or my wife when I am on duty. The count of days when thunder is heard will be *very* accurate as she is petrified of thunder and always notes its occurrence very carefully!
Note carefully that up to 31st December, 2003, the maximum temperature is for the whole 24hr from 0900 on one day, to 0900 on the next, read at 0900, but credited to the previous day. Similarly minimum temperatures cover the same period. On some occasions, it is not unlikely that maxima occur evening or overnight (air mass changes after cold day), or minima occur during the day, for similar reasons. Since 1st January, 2004, with an 1800 UTC reading, both day/night data, and 24hr data are shown in the appropriate file.