WEATHER REPORT.

New Zealand Herald, Volume XIV, Issue 4898, 28 July 1877, Page 1 (Supplement)

WEATHER REPORT.

UUK readeis will be good enough to observe that, in the present and future articles under this heading, the barometer averages given are deduced, not from the morning readings only, as hitherto, but from the mean of readings at a.m. and '-I'M p.m. on the previous evening. Striecly speaking, theiefore, they may not be compared with perfect accuracy against the average readings of previous corresponding periods ; the difference, however, in most ease?, is but trivial ; while at least part of the eri or arising from the " heavy range " of the barometer is thus avoided. To determine the amount of this error with accuracy, a continued series of observations, taken hourly over a. period of many mouths, or even years, would be necessary ; and this, of course, could only be undertaken by the stall' of a very and well appointed observatory station of the first order. For the first ten days of July the averrge hei'dit of the barometer has been 30'219 ; for'tho second ten days, 30"344 ; both these readings are abnormally high ; the mean height for July (13 years) being only 2!)-875. The maximum elevations have been .'>o 41 '2 (9Mi, a.m.) and 30'o'iC (10th, in.) ; the minimum depressions 129' SOS (Ist, |).m.) and 3o OD9 (12th, p.m.) Very high readings are generally noted during July, hut that of the tilth above cited is the highest within the present observer's record.

The approximate mean temperature has ranged between 43*0 and 55 0; the general means being, for the two decades, 40*3 and '49'S respectively. These figures are much below the usual average for the month ; the temperature <»f July (13 years) being 52*4 (normally). .Most of the nights have been cold ; and on the 9th, and again for four nighes successively, from tho l.'Kii to the lGtli, the radiation thermometer on the grass fell below the freezing point, reachiug its losvest ligure, 27 *0, on the 13th. The greatest cold degrees however marked by t!ie shade thermometer was 30*5 oil the 4th, and 35*2 on the 13th. The warmest days were the 7th, C*2*S, and tho 10th, 021. In IS7O the means for the corresponding periods were 57*7 and 53"2 ; but other atmospheric conditions were also widely different. The apptoximate means of the wet bulbs being for the two periods 47*- r.nd 47.0; we obtain dewpoint temperatures of 419 and 45*2, and humidity equivalent to S5Jt and 544 respectively. bust year both the dewpoint I and the humidity ranged for the same periods I very considerably higher, and the rainfall was jvs much above the average for July (13 years) as it has been, so far, below it. Up j to the present time the month hay boon i abnormally dry ; tho total fall being, from the lnt to the 10ch, 0"400 ; and from the 11th to the 20th, 0'175, or, in all, a little over half an inch. In the iirst twenty days of 1*570 there full 3*955 inches ; and, in the same time in 1875, 4*905 inches. (N. B.—The rain of tho 2l»t aud 22nd only increases the total record to a little over one inch and a quarter). On eight days out of tho twenty, no raiu fell ; while the amount of cloud wind uas been remarkably small : the average o( the morning readings gives 4 and 5 respectively ; while the approximate amount for day and night gives 3*2 aud 3'3 for the same periods. The forms of cloud .most usual have been masses or strakes, either on the horizon opposite to the prevailing wiud, or more dillused aud breaking away into lighter and higher clouds, and cumulus round the horizon, without any apparent reference to the direction of the wind. The wind has been mostly light, especially in the second decade, averaging and 183 miles per diem, or 1U and 74 miles per hour. In IS7G the average a were about 14 and 15 miles per hour. On seven days out of the twenty its direction has been S , varying on six more to east or west of that quarter, in equal proportions ; two days each for E., N.K., and iS.W. ; and one day S. complcte tho number. iNo observations of solar radiation have been taken during the month. The observer was unable, owing to other pressing engagements, to furnish his usua report at the close of the first ten days, and lias therefore combined his remarks upon the two periods.