Kirkwall, sunrise to sunset, 1997–2020
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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 24 years, 2.2% of daylight visibility records missing, 14.3% of daylight precipitation records missing, 1.7% of daylight wind records missing.

This is the analysis for the average of 24 years  (1997–2020).
Time slot: sunrise to sunset  (all daylight hours); click below on any-hour, or on the start time for a specific 2-hour slot (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 all daylight hours) 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 0 0 0 0 0 0 0 0 ​ 1  0%
≤ 10 mph 1 1 1 0 0 0 0 1 1 1 1 2 ​ 8  2%
≤ 15 mph 3 2 2 2 3 2 2 3 3 2 3 3 ​ 31  9%
≤ 20 mph 5 3 4 4 5 4 4 4 4 4 4 5 ​ 49  14%
≤ 30 mph 7 6 5 5 6 5 5 5 5 5 6 7 ​ 67  18%
≤ 40 mph 7 6 6 6 6 5 5 6 6 6 6 7 ​ 70  19%
any wind 7 6 6 6 6 5 5 6 6 6 6 7 ​ 72  20%
‘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 all daylight hours) 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
≤ 15 mph −0.1 +0.1 +0.1 +0.1 +0.1   +0.1 +0.1   +0.1 +0.2   ​+0.9
≤ 20 mph −0.1 +0.1 +0.1 +0.2 +0.1 +0.1 +0.2 +0.1   +0.2 +0.2   ​+1.3
≤ 30 mph −0.1 +0.2 +0.1 +0.3 +0.1 +0.2 +0.2 +0.2   +0.2 +0.2 +0.1 ​+1.6
≤ 40 mph −0.1 +0.2 +0.1 +0.3 +0.1 +0.2 +0.2 +0.2   +0.2 +0.2 +0.1 ​+1.8
any wind   +0.3 +0.1 +0.3 +0.1 +0.2 +0.2 +0.2   +0.2 +0.2 +0.1 ​+1.9
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 all daylight hours) the visibility was adequate. That is, for the entire day:
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
Good days 23 20 20 18 19 17 15 18 18 22 22 24 ​ 235  64%

Bad weather analysis

This is the number of days in each month, on average, for which (in all daylight hours) no bad weather occurred. That is, for the entire day, 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 9 7 7 8 8 7 6 7 7 7 7 9 ​ 88  24%

Wind speed analysis

This is the number of days in each month, on average, for which (in all daylight hours) 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 1 0 0 0 0 0 0 0 0 0 1 2 ​ 6  2%
≤ 10 mph 3 2 1 1 1 1 2 2 2 2 3 5 ​ 24  7%
≤ 15 mph 9 6 7 7 9 10 12 11 9 8 9 10 ​ 106  29%
≤ 20 mph 14 11 12 14 18 19 22 21 16 14 14 15 ​ 190  52%
≤ 30 mph 23 20 23 25 28 28 29 29 25 25 23 25 ​ 303  83%
≤ 40 mph 27 24 27 28 30 30 31 30 28 28 27 28 ​ 338  93%
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.