A Drought later this Year?

A recent newspaper article has explained how the rainfall between October and March is absorbed into the ground to replenish the aquifers deep below the surface, while rainfall between April and September is mainly taken up by the growing crops, plants and trees, or is lost by evaporation. So high winter rainfall is vital if water levels are to be maintained. In the local context, there seems to be a clear correlation between low winter rainfall and the drying up of the Pillhill Brook between East Cholderton and Amport later in the year.

These interesting charts of last year's weather show that the very high rainfall in October, 7½ inches, was followed by two months each with 2½ inches. Normally this would be a good start to the six winter months, but up to mid-­February there has been a bare 2½ inches extra, and we need a lot more rain before the end of March to keep the Pillhill Brook flowing later this year.  - DJSW  March 2005

Hosepipe Ban This Summer?

Earlier this year I wrote that the low winter rainfall between October and March, the key months for replenishing the aquifers beneath the surface, might result in water shortages. The final figure recorded here was 16.44 inches, of which 6.9 inches fell in October.

The recent average for these six months is 20.45 inches, so the shortfall has been about 4 inches, or 20%. Whether this will lead to a water shortage only time, and Southern Water, will tell: but sadly it remains a distinct possibility that the Pillhill Brook will once again dry out at East Cholderton later in the year. - DJSW, June 2005  

Autumn Rain - at last!

There was a time when the equinoctial gales brought heavy rain by the end of September, followed perhaps, if we were lucky, by an 'Indian summer', with the first frosts coming some time around the middle of October. By early November winter was beginning. No longer. We rarely seem to have much stormy weather to usher in the autumn, warm days linger long after the summer has ended and only the occasional night frost in October comes to blacken the dahlias in the garden. The lawns now seem to need mowing throughout the year.

Not least of the changes in this year's weather pattern, though we must hope only a temporary one, is the lack of rain. We had a deluge of 7.46 inches in October 2004, but the following twelve months averaged only a fraction over 2 inches a month compared with the usual 3 inches. Only October of this year, with 3.8 inches, prevented the situation from being even worse; November, too, started off with a useful amount - in the first two, stormy, days of the month as much rain fell as in the whole of November 2004 - and the three weeks from 18 October gave us a welcome 5.88 inches. So far, so good. But we need to go on like this if the water table is to rise to let the streams and rivers flow properly again, though as I write this, on 14 November, there are clear blue skies outside, the sun is shining brightly and we had our first proper 'dahlia frost' only last night. - DJSW, December 2005 

Rainfall - 2005

The rainfall for last year (measured in East Cholderton) was 26.2 inches - the lowest figure in 16 years of recording. Only in two months, October and December, was there more than 3 inches - just enough to get the Pillhill Brook flowing again through Waterloo Bridge after Christmas, having been dry for 24 weeks from 14 July. Last year's figure can be compared to the average over the same 16 years of 34.5 inches, so is about 75% - statistically not very serious, perhaps, but we need a lot of rain before the summer and so does most of Southern England. - DJSW, February 2006

Just a little rain ?

The last three months have seen a preponderance of cold dry days with easterly winds and many nights of frost. The spring equinox has done a little to bring much-needed rain, but not enough: rainfall in the key months for replenishing the underground aquifers, October to March, amounted to only 15.85 inches. A year ago, the figure for the same period was 16.44 inches, and these compare poorly with the recent average of over 20 inches for the same six months.

Despite these low figures, our gardens haven't done too badly - the RHS advice is that the plants need an inch every ten days (more than that sinks down below the roots and is lost); it is our own need for water that is at risk, because not enough rain is reaching the water-holding strata deep beneath the surface, from where it can be sourced by the water companIes. - DJSW May 2006  

Hot and Dry

In May I wrote of the continuing lack of rainfall in the previous six months. Perversely, May itself proved to be a very wet month, rain falling on 22 of the 31 days and totaling 4.32 inches. For many places May produced a record rainfall, though here the figure was even higher in 2002 with 5.03 inches. In June we had just under an inch and in July there was 2.17 inches, of which 0.82 inches fell in a black squall on the 22nd, right on cue as Amport Fete opened. Nevertheless, the Pillhill Brook ran dry at Waterloo Bridge on 10 July and with practically no rain for the first half of August it is not likely to flow again for some time.

The summer heatwave gave us some very high temperatures, the peak being on 19 July with a maximum shade temperature of 34.3°C (93.7°F) and from 11 July to 12 August the minimum night temperature never fell below 20°C - for those who like the heat, a glorious summer. DJSW Sept 2006  

Another late autumn

For the second year in succession we have had a late autumn this year: as I write the leaves have only just started to change colour and to come down, lawns are growing (and need mowing) vigorously and our first 'dahlia frost' did not come until the early hours of 2 November.

Everything is now very damp. October produced 5.17 inches of rain, which compares well with the average over the past 17 years of 4.07 inches. The first half of November gave us little more than a few showers and periods of drizzle, but since then it has rained frequently and often heavily, though we will need a very great deal before the end of December to come anywhere near the average for the year. 
- DJSW Dec 2006  

2006 – nine months dry, three months wet.

The first nine months of 2006 continued the very dry conditions of the previous year: only May was unusually wet, but otherwise the lack of rain caused the ground to dry out badly and by 10 July the Pillhill Brook had ceased to flow at Waterloo Bridge in East Cholderton.  Despite the cloudburst over Amport Fete in July, really wet conditions returned only in October: in each of the last three months of the year we recorded over five inches of rain, the water table rose strongly and the stream came back on 26 November, having been dry for 20 weeks.  By the end of the year we had recorded a total rainfall of 35.11 inches, just a shade over the recent average here.

It is interesting to see how much variation in the annual rainfall we have recorded over the past 17 years.  The lowest was 26.2 inches in 2005; the highest 49.25 inches in 2002 – between these two extremes the figures have been entirely random and no particular pattern emerges over the years in this, admittedly short, period of time. DJSW Feb 2007  

Heavy Winter Rain

It is said that the key months for replenishment of the aquifers deep underground are the six winter months, from the beginning of October to the end of March, when there is minimum evaporation and the plants have stopped taking up water for growth.  In 2006/7, we recorded 26.55 inches of rain in these six months, well above the recent average of about 20 inches (and in fact more than fell in all 12 months of 2005), so despite the dry spell of the last few weeks, we can hope there will be no hose-pipe bans, and that the Pillhill Brook will continue to flow throughout the year.     DJSW  May 2007

No April showers this year !

What a month April was, barely a cloud in the sky from beginning to end, and, by all accounts, the warmest April on record. Here we measured only 0.12 inches of rain in the whole month, the lowest of any calendar month over the last 18 years. There was a spell of 22 consecutive days, 31st March to 21st April, without any rain at all – the last time we had a similar run was in 1997 (21st March to 16th April). Interestingly, it is not unusual for there to be dry spells in March or April, often accompanied as in this year by very drying northerly or easterly winds. But what a contrast May has been: chill, windy and wet, with over 2¾ inches of rain. No global warming in sight at the moment!     DJSW June 2007

Rainfall in 2007

We measured just a shade under 36 inches of rain in East Cholderton last year, only about an inch more than the recent average; but this figure masks some quite considerable variations. For example, April - normally quite a wet month - was almost bone-dry throughout with only 0.12 inches (no April showers there!): and there was a long dry spell of 30 days, from 21 August to 19 September, in which no measurable rain fell at all. In marked contrast May, June and July were all unusually wet and we recorded 14.25 inches, an increase of nearly 60% on the average of 9 inches for these three months.

Such are the vagaries of the English weather that almost any month can turn out to be the wettest of the year, but the accolade must usually go to November, averaging about 4 inches; and our records here suggest that no month averages less than 2 inches. 
DJSW Feb 2008