June Statistics (look out for the temperature frequency)

[stephenprudence]

It's a little late as Ive been busy, but here are the statistics for June.

Very interesting reading, as June was a month with a high frequency of below average temperatures, more so at night with temperatures well below average in some cases. In the daytime the temperatures were overall above average however this was due to the warm spell later in the month. Some of these June temperatures are close to record lows, and may well be record lows for the start of the month. This is one month after recording a record low in May, and the only air frost I've ever seen in May. Certainly the early part of summer has been characterised by very low minima for the time of year.

June 2012 Statistics

Below are the statistics for my weather station during the month of June.

Mean Maximum: 17.9C
Mean Minimum: 10.3C
Overall Mean: 14.1

Monthly Rainfall total: 96.0mm
Rainfall days: 19
Max rainfall in one day: 13.5mm (3rd June)

Highest daily maximum temperature: 24.2C (28th June)
Lowest daily maximum temperature: 10.0C (3rd June)
Highest daily minimum temperature: 15.5C (27th June)
Lowest daily minimum temperature: 6.5C (7th June)

Temperature frequency breakdown:

Maximum temperature:

10-15C: 5 days
15-20C: 18 days
20-25C: 7 days

Minimum temperature:

5-10C: 10 days
10-15C: 19 days
15-20C: 1 day

Days with Ground Frost: 0
Days with Air Frost: 0
Days of falling snow: 0
Days of lying snow: 0

Compared to the June CET (71-00 average = 14.1), it comes in at 0C above/below the average, making it an average month.

[Nathan]

Here are the June statistics for Southsea:

Mean Maximum: 19.6C
Mean Minimum: 13.5C
Overall Mean: 16.6C

Monthly Rainfall total: 118.1mm
Rainfall days: 16
Max rainfall in one day: 27.0mm (11th June)

Highest daily maximum temperature: 25.8C (28th June)
Lowest daily maximum temperature: 13.4C (11th June)
Highest daily minimum temperature: 17.7C (27th June)
Lowest daily minimum temperature: 11.5C (12th June)

Temperature frequency breakdown:

Maximum temperature:

10-15C: 1 day
15-20C: 16 days
20-25C: 13 days

Minimum temperature:

5-10C: 0 days
10-15C: 25 days
15-20C: 5 days

Days with Ground Frost: 0
Days with Air Frost: 0
Days of falling snow: 0
Days of lying snow: 0

Compared to the June LTA for Portsmouth (71-00 average = 15.7), it comes in at 0.9C above the average, mainly due to night time temperatures being slightly above average.

Rainfall was however considerably above average & I suspect the wettest June on record for this location. The June LTA rainfall for Portsmouth is 40.0mm & I recorded nearly three times that amount.

[otorongo]

Compared to the June LTA for Portsmouth (71-00 average = 15.7), it comes in at 0.9C above the average, mainly due to night time temperatures being slightly above average.

I think averages, calculated as (max+min)/2 are not a good way of measuring accumulated heat.

A daytime high of 20C and a nighttime low of 10C will yield and average of 15C, regardless of the month, but the days in June are longer than, say, in March, so in June it's warmer (i.e. closer to the high) for longer.

If it's true that this past June "comes in at 0.9C above the average, mainly due to night time temperatures being slightly above average" as you say, it would most likely mean less accumulated heat for the plants, because the higher nighttime lows don't make up for the lower daytime highs, due to the nights being so much shorter than the days and therefore contributing less.

To get a better estimate of the accumulated heat, you would have take the average over shorter intervals - say hourly or every 15 minutes.

[stephenprudence]

I've tried using rolling averages but the truth is, the max+min/2 comes so close, that unless you are doing an important piece of research it really isn't worth it.

I tried the rolling mean (temperature every hour), and it only showed a 0.2C and 0.1C difference from the max+min/2 when trialled twice. It really isn't worth it for this endeavour.

[jcec1]

Central London Statistics

Mean Maximum: 20.6C
Mean Minimum: 13.1C
Overall Mean: 16.5C

Monthly Rainfall total: 150.2mm
Rainfall days: 21
Max rainfall in one day: 28.2mm (8th June)

Highest daily maximum temperature: 29.7C (28th June)
Lowest daily maximum temperature: 13.5C (03rd June)
Highest daily minimum temperature: 19.3C (27th June)
Lowest daily minimum temperature: 07.8C (04th June)

Temperature frequency breakdown:

Maximum temperature:

10-15C: 4 day
16-20C: 9 days
21-25C: 17 days

Minimum temperature:

05-10C: 3 days
11-15C: 22 days
16-20C: 5 day

[Dave Brown]

June 2012 Statistics

Below are the statistics for my Chalk weather station during the month of June.

Mean Maximum: 21.28C
Mean Minimum: 11.50C
Overall Mean: 16.39C

Monthly Rainfall total: 102.1mm
Rainfall days: 13
Max rainfall in one day: 14.5mm (3rd June)

Highest daily maximum temperature: 29.8C (28th June)
Lowest daily maximum temperature: 12,1C (3rd June)
Highest daily minimum temperature: 17.7C (27th June)
Lowest daily minimum temperature: 6.4C (13th June)

Temperature frequency breakdown:

Maximum temperature:

10-15C: 2 days
15-20C: 8 days
20-25C: 16 days
25-30C: 4 days

Minimum temperature:

5-10C: 7 days
10-15C: 21 days
15-20C: 2 day

Days with Ground Frost: 0
Days with Air Frost: 0
Days of falling snow: 0
Days of lying snow: 0

Compared to the June Greenwich (71-00 average = 15.15), it comes in at 1.34C above the average, making it an warm month. Here the daytime temps were up by 1.18C with night temps up by 0.4C, but didn't feel it due to extensive cloud cover.

We had less days with rainfall than many places, although at 102.1mm was a fraction over double the 51.0mm LTA. My feeling is that sunshine levels were well down.

[Nathan]

Compared to the June LTA for Portsmouth (71-00 average = 15.7), it comes in at 0.9C above the average, mainly due to night time temperatures being slightly above average.

I think averages, calculated as (max+min)/2 are not a good way of measuring accumulated heat.

A daytime high of 20C and a nighttime low of 10C will yield and average of 15C, regardless of the month, but the days in June are longer than, say, in March, so in June it's warmer (i.e. closer to the high) for longer.

If it's true that this past June "comes in at 0.9C above the average, mainly due to night time temperatures being slightly above average" as you say, it would most likely mean less accumulated heat for the plants, because the higher nighttime lows don't make up for the lower daytime highs, due to the nights being so much shorter than the days and therefore contributing less.

To get a better estimate of the accumulated heat, you would have take the average over shorter intervals - say hourly or every 15 minutes.

It perhaps isn't the best way, but it is the easiest way to work out the "average" & the same way the Met Office work out their averages, so it is the only thing we have to compare to... Besides don't plants do most of their growing at night? I find that if night time temperatures stay above 12C then everything in the garden romps away

[otorongo]

They grow at night but they accumulate energy during the day. That's why things grow faster in the greenhouse.

I think another useful parameter is the sea water temperature - not for June specifically but the total heat gain this year, with the most recent weeks having the most impact - before it starts cooling again. From http://www.surf-forecast.com/breaks/Brighton_1/seatemp :

Today's Brighton sea temperature is 14.3 °C.

Statistics for 13 Jul (1981–2005) – mean: 15.4 °C, range: 14.3 °C to 16.7 °C

The above speaks for itself

[GoggleboxUK]

The Met Office summary for the UK:

June 2012

The weather was dominated by low pressure over or close to the UK, with associated weather fronts. These brought rather cool days, some very large rainfall totals and also some strong winds early in the month. There was an almost complete absence of warm, settled spells.

The UK mean temperature was 0.3 °C below the 1971-2000 average and it was the coolest June since 1991. Daily maximum temperatures were well below normal, particularly in many central and eastern areas, with few warm days. Almost all areas were much wetter than normal, especially across much of England and Wales, southern and eastern Scotland and Northern Ireland. It was the wettest June across the UK in the series from 1910 (wetter than June 2007), and the equal-wettest June in the England and Wales series from 1766 (shared with June 1860). Only the far north-west of Scotland was drier than normal. Almost all areas were duller than usual, and it was provisionally the second dullest June in the series from 1929. The far north-west of Scotland was the sunnier exception.

A maximum temperature of 28.6 °C was recorded at Gravesend (Kent) on the 28th. A minimum temperature of -3.5 °C was recorded at Loch Glascarnoch (Highland) early on the 5th. In the 24 hours ending at 0900 on the 23rd, 93.8 mm of rain fell at Blencathra (Cumbria). A wind gust of 82 mph. was recorded at Needles Old Battery (Isle of Wight) during the 8th.