So, how bad is this summer?

The summer is about two thirds over and there are two schools of thought as to how it is progressing. Some think it is very pleasant with good growing weather. Others think it is cool and wet. Statistics point towards the latter claim....but with reservations! It has been said many times that the manipulation of numbers can often produce the results you want to see and the following figures come with the same caveat. By using a ranking system from 1 to 112, with 1 being the warmest or driest since 1900 and 112 being the coolest or wettest since 1900, comparisons can be made. For example, June and July 1976 were both warm and dry. Using equal weighting, June 1976 produce 1+6=7 and July gave 8+16=24. The total therefore was 31. By way of contrast, the June and July of 1987 were both very poor and produced 86+86=172 for June and 56+92=148 for July, a 2-month total of 320. So far, the numbers for June are 67+94=161 and for July 90+59=149, a total of 310. It can be seen that using basic comparisons of temperature and rainfall, the first 2 months of this summer are up there with the worst of them! Let's hope that August 2011 is less forgettable than the early months of summer.

Wet, but could be wetter!

As the rain hammers down again, it looks as if the monthly average for July could be exceeded by the end of today. In recent years there have been several quite wet Julys. In 2009 measurable rain fell on 22 days, and in 2007 over 124 mm of rain fell, including the 41mm that was recorded on the 20th. Some of the most intense rainfall of the year can fall in July, and large totals over a very short time period are not that unusual. Kensington had 25 mm of rain in 12 minutes on the 11th July 1927, and on the same day 37 mm fell in 18 minutes at Balham. On the 26th July 1946 there was a fall of 50 mm in 35 minutes at Kew. Some parts of Greater London have had over 100 mm in 24 hours and southeast London appears to be particularly vulnerable to these heavier falls. Over most of London it looks as if 1918 had the wettest July with parts of southeast and east London recording over 200 mm of rain. West London fared better with only 121 mm of rain at Kew, a figure this month is moving towards; but will it reach it?

A touch of optimism for July, maybe!

The general consensus is that this July has been poor so far. Statistics bear this out, with rainfall (up to the 10th) already 50% of the monthly average and temperatures the lowest for 23 years. The month has a long way to go and changes may occur. In some years they are marked. For example, in 1980, after a cool and wet June, holiday-makers were hoping for a better July. Alas, the first day of the month brought strong northerly winds, persistent rain and drizzle and a high of only 15. At midday in central London the temperature was only 12! A couple of dry and warmer days were then followed by more rain, and on the 8th another very cool, windy and wet day occurred with the 9th little better. No let up in the unsettled weather occurred until after mid month with infrequent sunshine and afternoon temperatures typically between 14 and 17. Finally, a sunny day occurred on the 21st, and although the maximum was only 19, it was the beginning of a spell of summery weather that lasted until the last couple of days of the month. On the 25th the temperature reached 28. Despite the warm end to the month, July 1980 was the coldest since 1922, and in recent years, although poor Julys have occurred, none of them have approached the dire weather experienced during the first 3 weeks of that very forgettable month.

July, the best summer month?

It can be argued that July is the best month of the year even though many of the high temperature records have occurred in August. Looking at the statistics for Morden, these covering the last 22 years, it would appear that day-time temperatures for July are 0.2 degrees warmer than those for August (23.3 against 23.1). Rainfall is 12mm less in July compared with August (43 against 55), in fact in recent years July averages out as the second driest month of the year behind March. All the summer months, along with May, only have 11 days with significant rainfall (0.2mm or more), but it's the subtleties that make July the best month. It hasn't the same number of very chilly days that can often spoil a June (Only 2 of the last 22 Julys have had maximum temperatures below 16, yet 17 Junes have had chilly days including a high of only 11.8 in 1998). August has had 2 years with maxima of 16, but in most years there is a distinct feel of autumn late in the month as the heat from the sun becomes less apparent. So, that's the argument for July, and today is a perfect example. Light winds, a mix of clouds and sun and a temperature of 24. Unfortunately, by Wednesday we'll be seeing the bad side of July weather!

A barbecue summer

As the baying pack from the media continue to taunt the rather disingenuous attempt by the Met. Office to tell us it almost is a 'barbecue summer', let's find a few facts ........at least for this part of the country where 15 million potential barbecuers live.

There is a reason why barbecues are more common in Mediterranean countries and the USA than here. They have warm and dry summers, and we don't. Up until the mid 70s plastic macs donned for a trip to the pub were more common than plastic plates and cups on the patio, but then the summer of '76 arrived. The general public realized that the sky didn't leak every day, and suddenly al fresco hit London. The barbecue grills rusted for a while in the late 70s and 80s, but from the end of the decade onwards a barbecue grill became a 'must have' along with the 4-wheel drive and a mobile phone. In many years the weather co-operated, but in this summer, like in its two predecessors, plastic mac days returned.

The official statistics put an emphasis on the mean temperature and the total rainfall, but if the nights are cloudy and windy they're often milder than after warm and sunny days. Perhaps more relevant are 'days' with rain falling and daily maximum temperatures, and these paint a poorer picture of the summer weather so far this year.

May, perhaps perceived as a tad early for a trip outside, did produce a few reasonable days during the last week, and June was a pleasant month in London. However, using maximum temperatures, it ranked cooler than the recent Junes of '76 , '89, '92, '96, '03, '04 and '06. Although rainfall totals were below average, the number of days when rain was recorded was above normal

For many people in Southeast England July was a poor month. After the 2nd, winds were from the southwest on nearly every day. The breezes were brisk at times and on the south coast they were often fresh or strong. The temperature has failed to rise above 21 Celsius since 3rd July on the Sussex coast, and although it has been somewhat warmer at times inland, in south London there have only been 4 cooler Julys (based on maximum temperatures) in the last 20 years! The other interesting statistic is with regard to rainfall. Okay, it was a wet month around London, but not exceptionally so. However, measurable rain fell on 20 days.....4 more than the previous July record during 20 years of observations, and what's more 6 of the remaining 11 days had some rain, but not enough to measure.

The Met. Office have 'revised' their forecast for the rest of the summer, but while they keep digging their hole, it remains to be seen if nature has the last laugh and produces a warm and dry August.