Apgar Village
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Apgar Village clear sky chart from 2005-11-05 to 2018-01-12.

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
31%
15736
9%
48373
6%
15702
33%
15702
14%
36841

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
14%
926
3%
2822
2%
921
16%
921
4%
2569
January16th to endNight
18%
768
8%
2688
5%
768
22%
768
8%
2229
February1st to 15thNight
17%
704
4%
2368
2%
700
20%
700
7%
2039
February16th to endNight
18%
632
6%
1945
4%
632
20%
632
7%
1674
March1st to 15thNight
19%
720
3%
2109
2%
720
20%
720
8%
1797
March16th to endNight
21%
768
3%
2103
1%
768
24%
768
8%
1811
April1st to 15thNight
28%
644
6%
1724
3%
644
29%
644
14%
1380
April16th to endNight
32%
540
9%
1620
7%
540
34%
540
14%
1215
May1st to 15thNight
44%
488
9%
1554
10%
488
45%
488
19%
1087
May16th to endNight
46%
375
6%
1309
8%
374
46%
374
13%
969
June1st to 15thNight
44%
360
4%
1260
4%
360
45%
360
18%
854
June16th to endNight
51%
360
7%
1260
5%
360
53%
360
23%
777
July1st to 15thNight
67%
340
12%
1190
11%
340
69%
340
45%
545
July16th to endNight
68%
376
22%
1360
27%
354
76%
354
49%
555
August1st to 15thNight
68%
450
21%
1522
22%
448
74%
448
46%
713
August16th to endNight
60%
573
27%
1719
21%
573
63%
573
44%
897
September1st to 15thNight
57%
687
19%
1848
12%
687
60%
687
39%
1080
September16th to endNight
51%
716
19%
1980
14%
716
53%
716
29%
1288
October1st to 15thNight
35%
720
11%
2082
7%
720
39%
720
18%
1523
October16th to endNight
34%
768
10%
2496
8%
768
37%
768
15%
1864
November1st to 15thNight
16%
831
6%
2541
3%
831
19%
831
8%
2140
November16th to endNight
16%
975
3%
2828
1%
975
17%
975
7%
2440
December1st to 15thNight
16%
975
4%
2925
3%
975
17%
975
7%
2572
December16th to endNight
12%
1040
2%
3120
1%
1040
14%
1040
5%
2823

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
15%12%46%5%24446%32%
48981
Night
16%15%46%423345%31%
48531
Cloud CoverDay
17%13%46%424445%32%
48982
Night
17%16%46%423345%30%
48534
TransparencyDay
53%8%13%15%7%1
48643
Night
56%8%12%14%6%1
48373
SeeingDay
23%17%29%20%8%1
6239
Night
27%9%27%25%9%
15737

By Month

Percentage Cloud Cover NW (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
22%28%7%11%42322410%
1371
16th to endDay
18%25%8%9%32332417%
1536
February1st to 15thDay
20%23%6%8%5%2334417%
1494
16th to endDay
13%24%9%11%5%2434416%
1527
March1st to 15thDay
19%24%6%7%5%2333417%
1851
16th to endDay
20%23%5%6%5%34446%14%
2119
April1st to 15thDay
15%17%5%8%7%45%5%5%5%18%
2222
16th to endDay
16%16%5%8%6%24345%26%
2340
May1st to 15thDay
14%9%36%5%35%45%6%33%
2392
16th to endDay
20%8%36%6%46%5%5%7%25%
2802
June1st to 15thDay
22%6%36%6%46%46%5%27%
2700
16th to endDay
17%4245%35%5%5%7%38%
2700
July1st to 15thDay
5%31332445%6%57%
2700
16th to endDay
321221335%6%67%
2711
August1st to 15thDay
6%21332346%8%58%
2428
16th to endDay
7%313333446%57%
2483
September1st to 15thDay
9%425%424446%51%
2108
16th to endDay
14%5%25%5%23446%43%
1980
October1st to 15thDay
18%10%36%5%35%446%31%
1875
16th to endDay
21%12%46%42345%7%27%
1728
November1st to 15thDay
25%22%5%8%42223418%
1634
16th to endDay
18%21%6%8%5%24346%18%
1459
December1st to 15thDay
19%23%8%10%5%2433414%
1365
16th to endDay
18%29%8%10%42333410%
1456
January1st to 15thNight
22%26%6%9%5%2323411%
2822
16th to endNight
18%25%7%7%42333420%
2688
February1st to 15thNight
19%22%6%8%5%3433418%
2357
16th to endNight
13%24%8%10%6%2333419%
1945
March1st to 15thNight
20%20%5%8%423345%19%
2109
16th to endNight
19%20%5%7%5%24445%20%
2100
April1st to 15thNight
14%14%35%7%34447%29%
1724
16th to endNight
16%12%46%6%23445%33%
1620
May1st to 15thNight
12%7%25%5%35%5%7%7%37%
1553
16th to endNight
18%6%26%5%36%46%7%32%
1309
June1st to 15thNight
19%5%343235%47%38%
1260
16th to endNight
15%41342445%6%46%
1260
July1st to 15thNight
4212212247%68%
1260
16th to endNight
321211246%73%
1455
August1st to 15thNight
421321235%11%62%
1530
16th to endNight
5%11231335%6%65%
1719
September1st to 15thNight
6%3133235%46%59%
1848
16th to endNight
11%5%23323447%49%
1980
October1st to 15thNight
17%8%26%425%45%6%37%
2082
16th to endNight
20%11%25%5%24347%32%
2496
November1st to 15thNight
23%20%45%5%23335%21%
2541
16th to endNight
21%21%6%7%6%2333418%
2828
December1st to 15thNight
17%26%7%10%5%3432315%
2925
16th to endNight
17%30%8%10%5%2322312%
3120

Percentage Cloud Cover SW (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
25%27%8%9%32222311%
1371
16th to endDay
20%25%8%7%42322418%
1536
February1st to 15thDay
19%27%6%7%41333317%
1494
16th to endDay
14%26%9%10%5%3333416%
1527
March1st to 15thDay
21%27%5%7%42333416%
1851
16th to endDay
22%25%5%7%5%24345%14%
2120
April1st to 15thDay
16%20%48%7%3445%5%18%
2222
16th to endDay
18%17%47%5%34345%25%
2340
May1st to 15thDay
16%10%36%6%3445%6%32%
2392
16th to endDay
21%8%37%7%35%5%6%6%24%
2802
June1st to 15thDay
24%6%36%5%36%45%6%27%
2700
16th to endDay
20%424435%5%5%7%37%
2700
July1st to 15thDay
7%3123245%5%6%56%
2700
16th to endDay
421221435%6%65%
2711
August1st to 15thDay
6%21332345%7%58%
2428
16th to endDay
7%413423446%56%
2483
September1st to 15thDay
10%4245%24345%51%
2108
16th to endDay
16%5%26%5%2335%6%42%
1980
October1st to 15thDay
21%9%25%5%36%35%6%30%
1875
16th to endDay
24%11%345%2335%6%27%
1728
November1st to 15thDay
29%23%5%6%322235%17%
1634
16th to endDay
18%24%6%7%324435%18%
1459
December1st to 15thDay
18%24%8%9%42323415%
1365
16th to endDay
19%29%8%10%422235%10%
1456
January1st to 15thNight
25%25%7%9%5%2322411%
2822
16th to endNight
18%26%7%7%32223420%
2688
February1st to 15thNight
21%24%6%9%5%3222418%
2357
16th to endNight
14%26%8%8%5%3333417%
1945
March1st to 15thNight
21%23%5%7%424335%18%
2109
16th to endNight
21%23%46%42434419%
2103
April1st to 15thNight
15%19%35%5%23346%28%
1724
16th to endNight
18%13%46%434335%33%
1620
May1st to 15thNight
14%9%235%35%5%6%7%37%
1553
16th to endNight
19%6%25%6%25%5%6%7%32%
1309
June1st to 15thNight
20%5%3432446%5%39%
1260
16th to endNight
16%423325%45%7%44%
1260
July1st to 15thNight
6%111212247%67%
1260
16th to endNight
411112235%72%
1455
August1st to 15thNight
421221335%10%61%
1530
16th to endNight
6%112323347%63%
1719
September1st to 15thNight
6%2143235%5%5%58%
1848
16th to endNight
14%5%24223437%49%
1980
October1st to 15thNight
18%8%25%43345%7%36%
2082
16th to endNight
23%10%3442435%6%31%
2496
November1st to 15thNight
25%22%44413335%20%
2541
16th to endNight
23%21%6%7%5%2323418%
2828
December1st to 15thNight
17%27%6%10%5%3422415%
2925
16th to endNight
18%31%8%9%5%2322313%
3120

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
79%7%7%31
1371
16th to endDay
71%7%11%6%11
1536
February1st to 15thDay
72%9%9%5%2
1494
16th to endDay
73%7%8%6%2
1527
March1st to 15thDay
72%9%11%6%
1851
16th to endDay
73%8%11%5%
2120
April1st to 15thDay
68%10%12%8%
2222
16th to endDay
62%8%12%13%11
2340
May1st to 15thDay
52%9%17%14%6%
2392
16th to endDay
58%11%16%9%2
2807
June1st to 15thDay
58%8%11%14%5%
2700
16th to endDay
45%9%15%21%8%
2700
July1st to 15thDay
27%8%13%27%18%3
2541
16th to endDay
17%6%11%28%30%4
2543
August1st to 15thDay
23%8%16%32%16%3
2411
16th to endDay
28%7%13%26%20%3
2483
September1st to 15thDay
34%7%13%23%17%3
2108
16th to endDay
42%8%14%22%10%1
1980
October1st to 15thDay
54%10%16%13%4
1875
16th to endDay
57%11%16%12%2
1728
November1st to 15thDay
72%7%9%6%3
1634
16th to endDay
67%12%13%5%2
1459
December1st to 15thDay
73%7%9%8%1
1365
16th to endDay
77%7%9%41
1456
January1st to 15thNight
79%7%5%5%2
2822
16th to endNight
68%7%9%10%31
2688
February1st to 15thNight
71%8%9%6%3
2368
16th to endNight
71%7%8%9%2
1945
March1st to 15thNight
68%9%13%7%
2109
16th to endNight
68%9%11%9%1
2103
April1st to 15thNight
58%9%16%13%1
1724
16th to endNight
55%8%14%16%4
1620
May1st to 15thNight
44%11%18%17%7%
1554
16th to endNight
49%13%18%13%4
1309
June1st to 15thNight
45%9%16%20%7%
1260
16th to endNight
37%9%19%22%10%
1260
July1st to 15thNight
19%413%33%22%6%
1190
16th to endNight
15%410%29%31%8%
1360
August1st to 15thNight
17%7%16%38%16%4
1522
16th to endNight
20%6%12%31%24%3
1719
September1st to 15thNight
24%9%15%26%18%4
1848
16th to endNight
34%10%15%24%12%2
1980
October1st to 15thNight
47%11%18%17%5%
2082
16th to endNight
53%9%16%16%3
2496
November1st to 15thNight
67%9%10%7%4
2541
16th to endNight
71%7%12%6%2
2828
December1st to 15thNight
75%6%8%8%1
2925
16th to endNight
79%5%8%41
3120

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
29%7%21%18%18%4
82
16th to endDay
37%15%31%10%4
64
February1st to 15thDay
37%15%28%12%5%
77
16th to endDay
37%17%24%17%3
186
March1st to 15thDay
43%24%23%6%1
270
16th to endDay
38%21%29%8%2
288
April1st to 15thDay
31%20%33%11%2
269
16th to endDay
30%20%27%14%6%
270
May1st to 15thDay
24%20%26%20%6%
301
16th to endDay
25%11%22%23%14%2
517
June1st to 15thDay
20%16%28%20%10%2
495
16th to endDay
19%14%27%24%12%1
495
July1st to 15thDay
9%11%29%33%13%1
475
16th to endDay
5%21%40%23%7%
380
August1st to 15thDay
8%15%36%29%8%1
315
16th to endDay
8%16%38%25%10%1
332
September1st to 15thDay
21%22%24%23%5%2
315
16th to endDay
18%24%31%17%6%1
315
October1st to 15thDay
30%16%31%19%2
216
16th to endDay
30%17%25%16%8%2
144
November1st to 15thDay
37%14%27%17%2
135
16th to endDay
35%19%31%6%7%
112
December1st to 15thDay
33%12%30%13%10%1
90
16th to endDay
26%17%36%15%4
96
January1st to 15thNight
41%11%24%18%3
926
16th to endNight
33%8%35%18%4
768
February1st to 15thNight
32%9%33%19%3
704
16th to endNight
27%12%33%21%4
632
March1st to 15thNight
35%14%27%19%3
720
16th to endNight
35%10%29%19%4
768
April1st to 15thNight
25%12%28%24%8%
644
16th to endNight
27%10%25%25%9%1
540
May1st to 15thNight
19%8%23%32%14%1
489
16th to endNight
22%6%18%31%19%1
375
June1st to 15thNight
21%7%23%29%16%1
360
16th to endNight
18%423%33%19%
360
July1st to 15thNight
7%5%16%51%18%
340
16th to endNight
5%419%52%17%
376
August1st to 15thNight
5%419%47%22%
450
16th to endNight
6%7%21%41%21%1
573
September1st to 15thNight
8%6%25%31%23%4
687
16th to endNight
17%8%20%33%18%2
716
October1st to 15thNight
23%7%30%29%8%
720
16th to endNight
29%8%24%30%7%
768
November1st to 15thNight
38%12%28%18%2
831
16th to endNight
35%13%29%17%3
975
December1st to 15thNight
32%10%33%19%3
975
16th to endNight
35%12%32%16%2
1040
Page generated at 2018-01-12 20:01:27. Version ac04

Copyright 2018 A. Danko


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