Kirkwall, 18:00 to 20:00, 1997–2015
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Met Office station 23: Kirkwall, Orkney  (KW17 2); OS grid reference: SY 482077.
Coordinates:  N58°57'14" W2°54'00"  (58.954 -2.900), elevation 26 m.
Note: gusts not recorded in 6 out of the 19 years, 1.9% of daylight visibility records missing, 18.5% of daylight precipitation records missing, 1.6% of daylight wind records missing.

This is the analysis for the average of 19 years  (1997–2015).
Time slot: 18:00 to 20:00  (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 0 0 0 0 1 0 1 1 0 0 0 0  3  1%
≤ 10 mph 0 0 0 2 4 4 4 6 0 0 0 0  20  6%
≤ 15 mph 0 0 0 5 12 11 11 12 0 0 0 0  51  14%
≤ 20 mph 0 0 0 7 16 16 15 15 0 0 0 0  67  18%
≤ 30 mph 0 0 0 8 17 17 16 16 0 0 0 0  75  20%
≤ 40 mph 0 0 0 8 18 17 16 16 0 0 0 0  75  21%
any wind 0 0 0 8 18 17 16 16 0 0 0 0  75  21%
‘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 19 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                           
≤ 10 mph       +0.1   +0.2 +0.2             
≤ 15 mph       +0.1 +0.2 +0.5 +0.5 +0.1          +0.1
≤ 20 mph       +0.2 +0.1 +0.5 +0.5 +0.1          +0.1
≤ 30 mph       +0.2 +0.1 +0.4 +0.5 +0.1          +0.1
≤ 40 mph       +0.2 +0.1 +0.4 +0.5 +0.1          +0.1
any wind       +0.2 +0.1 +0.4 +0.5 +0.1          +0.1
Empty cells indicate negligible change; ‘Total’ shows the average trend 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 0 0 0 12 27 25 24 23 0 0 0 0  111  30%

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 14 14 17 18 20 19 19 20 17 16 14 14  202  55%

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 2 1 2 2 1 1 2 2 2 2 2 3  21  6%
≤ 10 mph 5 4 7 6 7 7 9 9 9 6 5 7  80  22%
≤ 15 mph 13 12 15 15 17 18 21 21 18 14 13 14  190  52%
≤ 20 mph 19 16 20 22 24 25 28 27 24 21 18 20  263  72%
≤ 30 mph 26 24 28 28 30 30 31 31 29 28 25 27  338  92%
≤ 40 mph 29 27 30 30 31 30 31 31 30 30 28 29  354  97%

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

All text Copyright © Mike Cowlishaw 2008, 2017. All rights reserved. The pages and data here are for non-commercial use only.
This page was last edited on 2017-01-01.