Doughton Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Doughton Park clear sky chart from 2005-11-05 to 2017-03-14.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
41%
15108
21%
45138
12%
15070
51%
15070
24%
28738

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
24%
718
23%
2327
8%
716
42%
716
19%
1413
January16th to endNight
21%
768
23%
2496
8%
768
40%
768
20%
1515
February1st to 15thNight
23%
701
23%
2255
8%
701
40%
701
20%
1354
February16th to endNight
17%
631
23%
1881
7%
631
33%
631
20%
1191
March1st to 15thNight
28%
716
23%
1969
10%
716
39%
716
23%
1272
March16th to endNight
25%
704
16%
1936
7%
704
33%
704
22%
1307
April1st to 15thNight
33%
658
21%
1756
7%
658
43%
658
25%
1122
April16th to endNight
37%
553
21%
1543
9%
553
47%
553
26%
999
May1st to 15thNight
40%
495
15%
1485
7%
495
46%
495
21%
1029
May16th to endNight
56%
513
13%
1540
8%
513
58%
513
26%
1012
June1st to 15thNight
63%
495
14%
1485
13%
495
65%
495
28%
975
June16th to endNight
68%
495
15%
1485
13%
495
71%
495
32%
926
July1st to 15thNight
66%
465
12%
1395
10%
465
67%
465
26%
935
July16th to endNight
73%
522
12%
1469
10%
489
75%
489
30%
933
August1st to 15thNight
62%
494
15%
1474
13%
491
63%
491
24%
1007
August16th to endNight
67%
591
16%
1641
13%
591
67%
591
27%
1147
September1st to 15thNight
61%
660
21%
1795
17%
660
63%
660
27%
1196
September16th to endNight
49%
657
17%
1815
13%
657
52%
657
22%
1262
October1st to 15thNight
46%
660
26%
1936
21%
660
55%
660
28%
1199
October16th to endNight
43%
704
32%
2112
20%
704
59%
704
33%
1196
November1st to 15thNight
45%
700
27%
2167
18%
700
57%
700
31%
1233
November16th to endNight
37%
720
26%
2340
17%
720
50%
720
26%
1359
December1st to 15thNight
30%
720
23%
2340
12%
720
45%
720
20%
1484
December16th to endNight
23%
768
21%
2496
9%
768
38%
768
16%
1672

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
14%5%25%5%35%5%5%7%38%
45558
Night
14%5%2442445%7%44%
45331
Cloud CoverDay
14%6%25%5%35%5%5%7%38%
45568
Night
14%5%2442445%7%44%
45335
TransparencyDay
42%8%12%18%14%3
45269
Night
37%7%13%20%16%3
45138
SeeingDay
19%10%19%21%17%11%
4826
Night
17%11%22%26%18%3
15115

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
15%7%14435%5%35%42%
1611
16th to endDay
14%425%42335%5%46%
1728
February1st to 15thDay
11%8%2443346%5%43%
1604
16th to endDay
13%6%345%24446%43%
1592
March1st to 15thDay
15%424424346%45%
1952
16th to endDay
18%7%25%424345%39%
1936
April1st to 15thDay
13%4144245%5%7%47%
1861
16th to endDay
15%5%345%35%447%39%
2096
May1st to 15thDay
17%6%25%5%35%6%6%8%31%
2136
16th to endDay
13%6%16%6%35%6%6%9%33%
2223
June1st to 15thDay
11%5%26%6%47%6%7%8%30%
2145
16th to endDay
9%336%6%46%6%7%11%34%
2145
July1st to 15thDay
13%6%37%7%47%6%7%8%27%
2145
16th to endDay
10%5%37%7%6%8%8%9%9%24%
2283
August1st to 15thDay
14%6%27%8%5%7%6%7%9%24%
2145
16th to endDay
12%7%26%7%46%6%7%9%27%
2198
September1st to 15thDay
14%6%26%6%35%6%6%7%34%
1833
16th to endDay
23%6%36%5%33346%33%
1815
October1st to 15thDay
17%413334345%48%
1694
16th to endDay
16%414322235%51%
1760
November1st to 15thDay
10%413323346%55%
1688
16th to endDay
16%424423346%47%
1620
December1st to 15thDay
14%6%24434447%42%
1620
16th to endDay
20%7%15%423346%39%
1728
January1st to 15thNight
14%5%23324446%48%
2327
16th to endNight
14%7%23425%5%5%6%44%
2496
February1st to 15thNight
13%6%2332345%6%47%
2253
16th to endNight
13%425%4245%5%7%43%
1881
March1st to 15thNight
14%5%244345%5%6%44%
1957
16th to endNight
17%5%243345%46%41%
1936
April1st to 15thNight
12%6%1433435%8%45%
1756
16th to endNight
16%5%234145%5%6%44%
1543
May1st to 15thNight
16%7%245%3345%7%38%
1485
16th to endNight
13%425%4245%7%11%38%
1538
June1st to 15thNight
9%414336%6%7%11%41%
1485
16th to endNight
7%4244345%6%11%45%
1485
July1st to 15thNight
11%5%14435%5%8%11%38%
1485
16th to endNight
4435%5%36%6%7%12%39%
1577
August1st to 15thNight
15%425%5%26%5%6%8%38%
1485
16th to endNight
11%426%5%446%7%10%37%
1641
September1st to 15thNight
12%426%4245%6%7%41%
1795
16th to endNight
20%6%245%23435%40%
1815
October1st to 15thNight
16%5%14322346%49%
1936
16th to endNight
13%313313236%56%
2112
November1st to 15thNight
14%413313235%56%
2167
16th to endNight
15%414323346%50%
2340
December1st to 15thNight
16%5%25%424335%45%
2340
16th to endNight
21%7%24423446%36%
2496

Percentage Cloud Cover SE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
15%6%23435%445%42%
1611
16th to endDay
14%5%24423346%46%
1728
February1st to 15thDay
12%8%2442345%5%44%
1604
16th to endDay
13%6%35%434446%43%
1592
March1st to 15thDay
15%42442435%6%45%
1963
16th to endDay
18%7%25%425%346%39%
1935
April1st to 15thDay
13%4134145%5%7%47%
1861
16th to endDay
16%5%245%34447%39%
2096
May1st to 15thDay
16%7%25%5%45%5%6%8%32%
2136
16th to endDay
13%6%15%6%445%7%9%34%
2223
June1st to 15thDay
11%6%26%7%47%6%7%8%31%
2145
16th to endDay
9%426%6%45%7%7%11%34%
2145
July1st to 15thDay
13%6%36%7%46%7%7%8%27%
2145
16th to endDay
10%5%37%7%5%8%8%8%9%24%
2283
August1st to 15thDay
14%7%26%7%5%7%6%8%8%24%
2145
16th to endDay
13%7%26%7%46%6%7%10%28%
2198
September1st to 15thDay
14%6%26%6%35%6%6%7%35%
1833
16th to endDay
23%6%26%5%33345%34%
1815
October1st to 15thDay
17%413324335%48%
1694
16th to endDay
16%414322245%52%
1760
November1st to 15thDay
10%323323346%56%
1688
16th to endDay
16%5%24413436%47%
1620
December1st to 15thDay
14%6%24434446%42%
1620
16th to endDay
21%6%24423346%39%
1728
January1st to 15thNight
14%5%13324445%48%
2327
16th to endNight
14%7%233245%46%45%
2496
February1st to 15thNight
12%6%23324446%48%
2246
16th to endNight
12%5%2442445%7%44%
1881
March1st to 15thNight
14%5%24435%5%46%44%
1969
16th to endNight
16%6%25%434446%41%
1936
April1st to 15thNight
12%5%2432435%8%46%
1756
16th to endNight
17%5%2331345%7%44%
1543
May1st to 15thNight
17%7%245%3345%7%37%
1484
16th to endNight
13%5%25%4145%7%11%38%
1538
June1st to 15thNight
9%314436%7%6%11%41%
1485
16th to endNight
7%42442447%11%45%
1485
July1st to 15thNight
11%5%14435%48%11%38%
1485
16th to endNight
4435%5%46%6%8%11%40%
1577
August1st to 15thNight
15%425%435%5%6%8%38%
1485
16th to endNight
11%5%25%5%35%5%6%11%36%
1641
September1st to 15thNight
13%5%26%435%5%6%8%41%
1795
16th to endNight
21%6%245%23445%40%
1815
October1st to 15thNight
16%5%23313445%49%
1936
16th to endNight
13%313313335%57%
2112
November1st to 15thNight
14%412223235%56%
2167
16th to endNight
15%414323336%51%
2340
December1st to 15thNight
16%6%25%314345%45%
2340
16th to endNight
21%7%24424446%36%
2496

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
41%7%9%19%17%3
1612
16th to endDay
37%49%26%16%4
1728
February1st to 15thDay
37%6%12%21%17%4
1606
16th to endDay
40%414%20%16%2
1592
March1st to 15thDay
38%5%11%23%17%4
1963
16th to endDay
47%5%11%20%12%2
1936
April1st to 15thDay
33%6%14%23%16%5%
1861
16th to endDay
43%6%10%17%16%5%
2096
May1st to 15thDay
46%12%15%15%8%
2136
16th to endDay
43%11%14%20%8%2
2227
June1st to 15thDay
45%12%16%16%8%
2145
16th to endDay
40%11%14%18%12%1
2145
July1st to 15thDay
50%11%14%12%9%2
2006
16th to endDay
48%13%19%12%6%
2128
August1st to 15thDay
52%12%14%13%6%
2132
16th to endDay
49%10%15%16%6%1
2198
September1st to 15thDay
44%9%12%16%14%2
1833
16th to endDay
51%5%10%14%15%1
1815
October1st to 15thDay
37%6%10%22%17%5%
1694
16th to endDay
35%38%24%19%8%
1760
November1st to 15thDay
30%5%9%19%27%8%
1688
16th to endDay
37%49%20%22%4
1620
December1st to 15thDay
40%6%9%19%18%5%
1620
16th to endDay
45%412%16%16%3
1728
January1st to 15thNight
36%6%11%19%20%6%
2327
16th to endNight
38%5%10%22%18%4
2496
February1st to 15thNight
36%5%9%24%19%4
2255
16th to endNight
37%7%14%23%15%2
1881
March1st to 15thNight
39%5%11%23%15%4
1969
16th to endNight
43%5%13%21%13%2
1936
April1st to 15thNight
36%6%13%22%16%5%
1756
16th to endNight
38%6%12%18%17%6%
1543
May1st to 15thNight
44%8%14%20%10%
1485
16th to endNight
36%10%21%21%7%2
1540
June1st to 15thNight
33%13%20%22%9%1
1485
16th to endNight
31%10%20%21%12%3
1485
July1st to 15thNight
36%12%16%20%11%2
1395
16th to endNight
30%13%24%21%9%1
1469
August1st to 15thNight
41%10%16%16%13%1
1474
16th to endNight
40%10%16%21%9%1
1641
September1st to 15thNight
38%9%16%15%16%3
1795
16th to endNight
46%6%11%15%18%1
1815
October1st to 15thNight
36%5%11%22%19%3
1936
16th to endNight
30%38%25%23%7%
2112
November1st to 15thNight
31%48%19%25%10%
2167
16th to endNight
35%47%23%24%4
2340
December1st to 15thNight
40%6%9%19%17%6%
2340
16th to endNight
47%5%11%16%17%2
2496

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
30%23%30%12%31
90
16th to endDay
23%37%31%6%1
96
February1st to 15thDay
30%36%24%7%1
90
16th to endDay
25%26%34%10%2
93
March1st to 15thDay
17%23%28%20%9%
264
16th to endDay
24%17%25%20%9%2
224
April1st to 15thDay
20%19%20%24%11%3
210
16th to endDay
17%8%23%20%20%9%
210
May1st to 15thDay
20%11%27%19%12%8%
228
16th to endDay
18%416%23%19%17%
267
June1st to 15thDay
14%5%16%24%23%16%
255
16th to endDay
12%320%29%20%14%
255
July1st to 15thDay
17%220%19%22%18%
245
16th to endDay
12%8%25%27%24%
270
August1st to 15thDay
19%11%21%22%24%
253
16th to endDay
13%15%23%25%30%
268
September1st to 15thDay
14%37%17%34%23%
255
16th to endDay
25%5%16%20%19%12%
254
October1st to 15thDay
23%5%20%22%18%9%
255
16th to endDay
19%9%20%27%15%6%
272
November1st to 15thDay
19%11%23%26%13%5%
196
16th to endDay
20%24%14%32%7%1
90
December1st to 15thDay
21%27%30%14%6%
90
16th to endDay
40%14%33%11%
96
January1st to 15thNight
19%20%31%21%5%
720
16th to endNight
18%20%37%21%2
768
February1st to 15thNight
19%22%31%25%1
704
16th to endNight
16%25%38%18%2
631
March1st to 15thNight
19%18%30%26%4
716
16th to endNight
21%13%33%21%9%
704
April1st to 15thNight
17%20%26%25%9%
658
16th to endNight
20%11%25%29%13%1
553
May1st to 15thNight
19%7%25%29%16%1
495
16th to endNight
15%413%29%29%7%
515
June1st to 15thNight
10%115%32%33%5%
495
16th to endNight
8%112%31%40%5%
495
July1st to 15thNight
15%18%27%40%5%
465
16th to endNight
5%18%26%45%12%
522
August1st to 15thNight
17%9%30%35%7%
494
16th to endNight
13%6%25%44%9%
591
September1st to 15thNight
13%211%26%37%8%
660
16th to endNight
25%213%26%29%3
657
October1st to 15thNight
19%8%19%25%19%7%
660
16th to endNight
15%11%23%29%16%2
704
November1st to 15thNight
16%11%22%30%15%3
700
16th to endNight
18%15%24%28%11%1
720
December1st to 15thNight
20%15%27%26%9%
720
16th to endNight
26%16%26%24%5%
768
Page generated at 2017-03-15 11:32:41. Version ac04

Copyright 2017 A. Danko


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