Yeovilton, 10:00 to 12:00, 1997–2020
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Met Office station 1302: Yeovilton, Somerset  (BA22 8); OS grid reference: ST 551232.
Coordinates:  N51°00'22" W2°38'24"  (51.006 -2.640), elevation 20 m.
Note: gusts not recorded in 6 out of the 24 years, 1.1% of daylight visibility records missing, 1.6% of daylight precipitation records missing, 0.8% of daylight wind records missing.

This is the analysis for the average of 24 years  (1997–2020).
Time slot: 10:00 to 12:00  (two hours); click below for any-hour analysis, or a different start time, or for whole day analysis (all times are GMT):

any-hour  06:00  08:00  10:00  12:00  14:00  16:00  18:00  all-day

‘Flyable days’ analysis

This is the number of days in each month, on average, for which (in this timeslot) the visibility was adequate, and there was no bad weather, and the wind speed was less than or equal to that shown on the left.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
≤ 5 mph 3 2 2 3 3 3 4 4 3 3 3 4  36  10%
≤ 10 mph 8 6 6 9 9 9 11 10 9 8 7 8  100  27%
≤ 15 mph 13 12 14 16 17 17 19 19 17 15 13 13  185  51%
≤ 20 mph 15 14 17 20 21 20 22 21 20 18 15 15  217  59%
≤ 30 mph 15 15 18 21 22 21 23 22 21 19 16 16  230  63%
≤ 40 mph 16 16 19 21 22 21 23 22 21 20 17 16  234  64%
any wind 16 16 19 21 22 21 23 22 21 20 17 16  234  64%
‘Total’ shows the total flyable days, on average, in a year, and the same as a percentage.

Trend analysis

This is the average change (per year, over the 24 years) in the average number of days in each month for which (in this timeslot) the visibility was adequate, and there was no bad weather, and the wind speed was less than or equal to that shown on the left.

For example, if a value of +0.5 is shown for a given month then that implies that since 1997 the number of flyable days in that month has increased by (on average) half a day per year.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
≤ 5 mph             −0.1 −0.1   −0.1     −0.4
≤ 10 mph +0.1     +0.1 +0.2     −0.2   −0.1     −0.1
≤ 15 mph +0.1 +0.1 +0.1 +0.2 +0.2   +0.1 −0.1 +0.1 +0.1 −0.1   +0.7
≤ 20 mph     +0.1 +0.2 +0.2   +0.1 −0.1 +0.1     +0.1 +0.7
≤ 30 mph     +0.1 +0.2 +0.3   +0.1   +0.1       +0.8
≤ 40 mph     +0.2 +0.2 +0.3   +0.1   +0.1     +0.1 +1.0
any wind     +0.2 +0.2 +0.3   +0.1   +0.1     +0.1 +1.0
Empty cells indicate negligible change; ‘Total’ shows the sum of the trends over the whole year.

Visibility analysis

This is the number of days in each month, on average, for which (in this timeslot) the visibility was adequate. That is, for the entire timeslot:
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
Good days 22 20 23 26 27 26 28 27 25 25 22 22  294  81%

Bad weather analysis

This is the number of days in each month, on average, for which (in this timeslot) no bad weather occurred. That is, for the entire timeslot, there was no rain, hail, snow, snow on the ground, icing conditions, thunderstorms, etc.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
Good days 20 20 23 23 24 23 24 23 24 22 20 20  265  73%

Wind speed analysis

This is the number of days in each month, on average, for which (in this timeslot) the maximum (gust) wind speed was less than or equal to the value shown on the left.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
≤ 5 mph 6 5 5 4 3 4 4 5 5 4 7 8  59  16%
≤ 10 mph 14 10 10 11 11 13 13 14 13 12 14 16  151  41%
≤ 15 mph 23 20 22 21 23 24 25 26 24 23 23 24  277  76%
≤ 20 mph 26 24 26 27 28 28 29 29 28 27 27 27  327  90%
≤ 30 mph 29 27 29 29 31 30 31 31 30 30 29 29  353  97%
≤ 40 mph 30 28 30 30 31 30 31 31 30 31 30 31  362  99%

Please send any comments, questions, or corrections to me, Mike Cowlishaw, at mfc@speleotrove.com.

All text Copyright © Mike Cowlishaw 2008, 2021. All rights reserved. The pages and data here are for non-commercial use only.
This page was last edited on 2021-05-09.