F.D.A.T. Veteran's Point
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the F.D.A.T. Veteran's Point clear sky chart from 2005-11-05 to 2018-01-20.

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
61%
16493
21%
48458
17%
16452
66%
16452
31%
29876

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
45%
778
21%
2522
15%
776
55%
776
25%
1550
January16th to endNight
45%
788
25%
2551
19%
788
56%
788
29%
1525
February1st to 15thNight
45%
701
25%
2103
17%
698
55%
698
34%
1227
February16th to endNight
48%
631
26%
1810
16%
631
58%
631
34%
1076
March1st to 15thNight
56%
720
30%
1980
20%
720
64%
720
46%
1084
March16th to endNight
57%
768
26%
2112
19%
768
62%
768
42%
1203
April1st to 15thNight
59%
718
24%
1976
18%
718
63%
718
43%
1107
April16th to endNight
64%
720
28%
1815
19%
720
66%
720
43%
1076
May1st to 15thNight
70%
599
26%
1679
19%
599
73%
599
44%
926
May16th to endNight
74%
561
22%
1682
18%
561
75%
561
33%
1019
June1st to 15thNight
69%
540
14%
1620
12%
540
69%
540
25%
1092
June16th to endNight
69%
540
9%
1620
8%
540
69%
540
24%
1125
July1st to 15thNight
72%
510
8%
1530
6%
510
72%
510
22%
1071
July16th to endNight
75%
564
9%
1595
9%
531
76%
531
23%
1092
August1st to 15thNight
82%
539
9%
1609
8%
536
82%
536
28%
1058
August16th to endNight
66%
739
10%
2006
9%
739
66%
739
24%
1405
September1st to 15thNight
68%
720
10%
1980
9%
720
68%
720
21%
1424
September16th to endNight
62%
717
14%
1980
13%
717
63%
717
21%
1435
October1st to 15thNight
69%
720
26%
2072
27%
720
71%
720
32%
1289
October16th to endNight
64%
768
28%
2304
29%
768
69%
768
35%
1355
November1st to 15thNight
64%
760
28%
2281
24%
760
71%
760
37%
1303
November16th to endNight
57%
780
30%
2392
25%
780
66%
780
35%
1386
December1st to 15thNight
56%
780
27%
2535
24%
780
64%
780
30%
1469
December16th to endNight
57%
832
25%
2704
23%
832
63%
832
30%
1579

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
8%5%36%7%46%6%6%8%35%
49049
Night
7%425%5%35%5%6%8%44%
48667
TransparencyDay
43%6%13%18%13%5%
48750
Night
35%6%16%21%14%6%
48470
SeeingDay
9%212%21%25%27%
6278
Night
9%314%31%32%8%
16501

By Month

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
11%7%35%5%45%45%7%39%
1746
16th to endDay
10%5%25%4345%5%7%46%
1775
February1st to 15thDay
10%6%25%6%35%446%44%
1750
16th to endDay
9%435%6%35%447%44%
1661
March1st to 15thDay
6%3245%36%45%9%48%
1980
16th to endDay
8%4246%35%5%47%47%
2111
April1st to 15thDay
7%315%5%45%5%6%9%45%
1972
16th to endDay
6%325%6%35%6%6%8%44%
2145
May1st to 15thDay
6%3245%26%6%6%7%47%
2280
16th to endDay
8%426%6%47%6%7%9%34%
2431
June1st to 15thDay
10%5%37%9%47%7%7%9%25%
2340
16th to endDay
9%6%37%7%6%8%7%8%9%24%
2340
July1st to 15thDay
9%6%47%8%5%9%7%7%9%21%
2340
16th to endDay
8%7%48%9%5%8%7%7%8%23%
2465
August1st to 15thDay
6%6%39%10%6%8%7%8%11%22%
2340
16th to endDay
10%7%39%9%48%6%7%8%22%
2177
September1st to 15thDay
9%6%37%10%6%7%8%7%8%23%
1980
16th to endDay
12%7%38%8%5%7%6%7%9%21%
1980
October1st to 15thDay
10%6%27%6%36%6%6%7%34%
1887
16th to endDay
10%425%5%35%45%7%44%
1920
November1st to 15thDay
6%425%5%35%5%7%9%44%
1907
16th to endDay
9%7%35%5%35%5%46%43%
1895
December1st to 15thDay
10%5%36%5%345%5%8%40%
1755
16th to endDay
6%6%25%6%35%5%6%8%43%
1872
January1st to 15thNight
10%6%36%4345%6%7%41%
2522
16th to endNight
12%5%25%4245%5%6%45%
2551
February1st to 15thNight
11%5%24324445%51%
2103
16th to endNight
8%4245%35%35%7%50%
1810
March1st to 15thNight
6%31342345%8%55%
1980
16th to endNight
5%324423446%57%
2112
April1st to 15thNight
5%42342347%8%54%
1976
16th to endNight
6%32442446%8%53%
1815
May1st to 15thNight
5%21342445%8%56%
1679
16th to endNight
6%3245%25%6%7%9%44%
1682
June1st to 15thNight
7%5%26%6%36%6%8%10%33%
1620
16th to endNight
7%446%7%46%6%8%10%32%
1620
July1st to 15thNight
7%5%17%6%36%8%8%10%32%
1620
16th to endNight
5%5%35%8%47%6%8%10%33%
1703
August1st to 15thNight
3325%6%47%7%9%13%35%
1620
16th to endNight
9%7%27%6%35%6%7%11%31%
2006
September1st to 15thNight
7%5%25%6%5%8%7%7%10%31%
1980
16th to endNight
9%7%27%7%46%8%7%10%27%
1980
October1st to 15thNight
7%6%25%5%35%5%6%8%44%
2072
16th to endNight
8%5%245%24448%48%
2304
November1st to 15thNight
4425%4345%7%7%48%
2281
16th to endNight
8%42443446%8%48%
2392
December1st to 15thNight
9%424435%5%5%8%46%
2535
16th to endNight
8%424436%46%9%44%
2704

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
44%38%19%17%7%
1747
16th to endDay
36%38%19%21%10%
1775
February1st to 15thDay
40%37%14%20%13%
1752
16th to endDay
38%310%16%20%10%
1661
March1st to 15thDay
33%310%27%17%8%
1980
16th to endDay
36%311%20%20%7%
2112
April1st to 15thDay
34%5%9%21%22%7%
1972
16th to endDay
35%49%21%19%8%
2145
May1st to 15thDay
33%411%23%19%7%
2280
16th to endDay
42%416%19%13%2
2435
June1st to 15thDay
50%6%17%20%4
2340
16th to endDay
51%8%22%14%3
2340
July1st to 15thDay
51%11%21%13%1
2201
16th to endDay
53%10%20%14%1
2310
August1st to 15thDay
50%10%26%11%1
2327
16th to endDay
54%10%20%12%1
2177
September1st to 15thDay
54%9%19%12%4
1980
16th to endDay
54%6%16%13%6%1
1980
October1st to 15thDay
45%5%9%17%15%7%
1887
16th to endDay
39%36%16%22%11%
1920
November1st to 15thDay
34%47%23%23%6%
1907
16th to endDay
41%37%19%18%9%
1895
December1st to 15thDay
40%412%21%14%6%
1755
16th to endDay
37%414%21%15%7%
1872
January1st to 15thNight
40%39%21%15%7%
2522
16th to endNight
37%38%19%21%9%
2551
February1st to 15thNight
34%29%18%18%15%
2112
16th to endNight
32%5%12%19%21%8%
1810
March1st to 15thNight
25%313%29%20%6%
1980
16th to endNight
27%413%24%20%9%
2112
April1st to 15thNight
26%414%25%19%8%
1976
16th to endNight
28%411%27%20%7%
1815
May1st to 15thNight
26%416%27%17%8%
1680
16th to endNight
32%7%16%25%16%1
1684
June1st to 15thNight
41%8%21%24%3
1620
16th to endNight
42%9%24%18%4
1620
July1st to 15thNight
41%12%28%14%2
1530
16th to endNight
38%13%28%16%2
1595
August1st to 15thNight
33%12%38%13%1
1609
16th to endNight
42%10%28%16%1
2006
September1st to 15thNight
42%14%22%16%5%
1980
16th to endNight
47%9%19%17%41
1980
October1st to 15thNight
35%6%10%22%19%6%
2072
16th to endNight
34%39%17%23%10%
2304
November1st to 15thNight
31%311%23%22%6%
2281
16th to endNight
33%49%23%19%10%
2392
December1st to 15thNight
35%313%26%12%7%
2535
16th to endNight
35%413%26%12%7%
2704

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
21%5%37%23%5%5%
135
16th to endDay
12%13%33%22%13%3
109
February1st to 15thDay
6%13%26%27%18%6%
90
16th to endDay
11%8%30%29%18%1
162
March1st to 15thDay
5%7%28%32%22%3
270
16th to endDay
9%321%29%28%7%
288
April1st to 15thDay
5%422%29%26%11%
270
16th to endDay
7%214%25%28%21%
270
May1st to 15thDay
5%313%21%31%24%
288
16th to endDay
7%15%18%30%37%
331
June1st to 15thDay
13%15%17%25%36%
315
16th to endDay
7%213%23%52%
315
July1st to 15thDay
5%5%23%63%
305
16th to endDay
10%10%25%52%
326
August1st to 15thDay
6%311%22%56%
313
16th to endDay
14%16%22%53%
332
September1st to 15thDay
13%339%25%44%
315
16th to endDay
11%1114%31%39%
314
October1st to 15thDay
14%18%25%36%13%
315
16th to endDay
10%218%31%27%9%
336
November1st to 15thDay
7%211%34%34%9%
325
16th to endDay
10%120%38%23%5%
275
December1st to 15thDay
7%6%34%31%16%2
135
16th to endDay
4220%38%27%5%
144
January1st to 15thNight
13%5%26%35%18%1
780
16th to endNight
14%5%26%37%14%
788
February1st to 15thNight
12%430%35%14%1
704
16th to endNight
9%431%44%10%
631
March1st to 15thNight
6%427%44%16%1
720
16th to endNight
6%423%41%22%1
768
April1st to 15thNight
6%223%41%24%1
718
16th to endNight
7%316%45%25%1
720
May1st to 15thNight
7%211%44%31%3
600
16th to endNight
9%429%44%11%
563
June1st to 15thNight
10%1323%47%14%
540
16th to endNight
8%213%48%25%
540
July1st to 15thNight
10%110%48%28%
510
16th to endNight
5%110%53%28%
564
August1st to 15thNight
411%52%30%
539
16th to endNight
11%3114%43%25%
739
September1st to 15thNight
10%1116%47%21%
720
16th to endNight
12%2120%47%15%
717
October1st to 15thNight
10%25%30%41%9%
720
16th to endNight
10%211%35%33%5%
768
November1st to 15thNight
5%215%40%32%3
760
16th to endNight
9%320%39%24%2
780
December1st to 15thNight
10%419%36%26%2
780
16th to endNight
10%420%35%27%1
832
Page generated at 2018-01-21 12:19:31. Version ac04

Copyright 2018 A. Danko


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