Troy Space Gazebo
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Troy Space Gazebo clear sky chart from 2005-11-05 to 2017-09-17.

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
36%
15590
15%
46856
10%
15552
42%
15552
20%
32408

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
17%
896
10%
2506
4%
895
22%
895
12%
1999
January16th to endNight
20%
833
10%
2561
4%
833
26%
833
11%
1990
February1st to 15thNight
18%
701
9%
2273
2%
701
26%
701
10%
1752
February16th to endNight
22%
631
15%
1893
6%
631
32%
631
15%
1393
March1st to 15thNight
26%
720
15%
2067
9%
720
31%
720
17%
1511
March16th to endNight
33%
768
18%
2112
10%
768
40%
768
21%
1482
April1st to 15thNight
29%
604
14%
1814
7%
604
36%
604
19%
1270
April16th to endNight
35%
540
20%
1620
8%
540
46%
540
25%
1058
May1st to 15thNight
40%
540
15%
1620
10%
540
46%
540
22%
1114
May16th to endNight
48%
562
16%
1684
11%
561
55%
561
29%
1060
June1st to 15thNight
54%
393
16%
1308
16%
393
60%
393
28%
792
June16th to endNight
58%
415
19%
1315
18%
415
64%
415
32%
784
July1st to 15thNight
62%
510
16%
1360
14%
510
66%
510
40%
808
July16th to endNight
65%
564
19%
1518
15%
531
69%
531
39%
880
August1st to 15thNight
63%
539
19%
1609
14%
536
66%
536
35%
945
August16th to endNight
63%
573
23%
1719
17%
573
68%
573
36%
1002
September1st to 15thNight
57%
678
23%
1938
18%
678
61%
678
33%
1178
September16th to endNight
59%
665
24%
1837
19%
665
63%
665
35%
1127
October1st to 15thNight
46%
660
20%
1907
15%
660
53%
660
28%
1239
October16th to endNight
24%
704
14%
2192
8%
704
34%
704
16%
1567
November1st to 15thNight
37%
700
21%
2276
16%
700
45%
700
22%
1472
November16th to endNight
25%
720
14%
2426
9%
720
31%
720
14%
1737
December1st to 15thNight
17%
720
8%
2520
3%
720
24%
720
10%
1933
December16th to endNight
14%
954
7%
2781
2%
954
19%
954
9%
2315

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
13%8%46%6%35%5%5%7%32%
47899
Night
15%8%36%5%3445%6%36%
47036
Cloud CoverDay
13%8%47%6%35%5%5%7%32%
47909
Night
14%8%36%5%34446%36%
47040
TransparencyDay
49%6%11%19%11%1
47597
Night
47%6%11%21%11%1
46856
SeeingDay
16%9%27%24%15%7%
5805
Night
18%8%28%29%12%1
15598

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
16%14%6%10%8%45%5%5%5%17%
1432
16th to endDay
14%16%9%11%8%46%445%13%
1661
February1st to 15thDay
14%13%6%10%9%5%5%5%45%18%
1588
16th to endDay
13%14%5%10%8%5%5%436%22%
1580
March1st to 15thDay
17%10%5%7%7%25%45%6%26%
1882
16th to endDay
17%10%5%8%6%34446%27%
2112
April1st to 15thDay
18%9%5%5%43445%7%30%
2145
16th to endDay
16%8%35%5%3435%6%37%
2340
May1st to 15thDay
19%7%36%6%3445%6%32%
2331
16th to endDay
13%6%35%435%5%5%8%39%
2431
June1st to 15thDay
10%5%35%5%45%5%5%8%39%
2643
16th to endDay
9%437%6%47%6%7%10%34%
2640
July1st to 15thDay
6%5%25%5%35%6%6%8%44%
2520
16th to endDay
8%5%25%5%46%6%7%10%37%
2543
August1st to 15thDay
7%6%25%7%36%6%7%9%37%
2340
16th to endDay
10%5%36%5%35%5%6%9%39%
2480
September1st to 15thDay
13%6%25%5%35%5%5%8%39%
2010
16th to endDay
13%5%245%25%5%6%9%39%
1829
October1st to 15thDay
14%7%35%5%33447%39%
1722
16th to endDay
21%11%35%5%34345%31%
1678
November1st to 15thDay
13%8%35%5%35%35%6%37%
1582
16th to endDay
17%10%47%6%35%45%5%28%
1533
December1st to 15thDay
16%14%7%10%7%345%5%5%21%
1440
16th to endDay
21%16%8%9%6%25%335%16%
1437
January1st to 15thNight
21%11%5%7%7%45%34423%
2506
16th to endNight
12%14%6%9%7%45%5%46%23%
2561
February1st to 15thNight
14%13%5%7%7%35%5%45%26%
2271
16th to endNight
15%11%39%6%345%46%29%
1893
March1st to 15thNight
16%9%46%6%25%35%5%33%
2055
16th to endNight
15%7%46%5%34446%36%
2112
April1st to 15thNight
18%8%35%4445%5%5%35%
1814
16th to endNight
15%6%335%2445%7%40%
1620
May1st to 15thNight
18%5%35%5%2445%7%36%
1620
16th to endNight
11%424425%448%44%
1682
June1st to 15thNight
9%424435%45%8%45%
1308
16th to endNight
9%5%243235%6%7%46%
1315
July1st to 15thNight
7%42242345%8%53%
1440
16th to endNight
5%323425%5%6%10%52%
1623
August1st to 15thNight
5%3145%345%6%9%48%
1620
16th to endNight
9%5%1432335%7%52%
1719
September1st to 15thNight
10%5%2433345%6%50%
1938
16th to endNight
11%325%423447%49%
1837
October1st to 15thNight
16%6%24423446%43%
1907
16th to endNight
20%8%35%5%345%5%5%31%
2192
November1st to 15thNight
13%7%35%4245%5%6%40%
2276
16th to endNight
20%10%36%5%245%5%6%28%
2426
December1st to 15thNight
19%12%5%7%6%35%446%24%
2520
16th to endNight
22%15%6%9%6%35%435%17%
2781

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
17%14%5%9%9%46%5%45%17%
1432
16th to endDay
14%16%9%11%8%45%5%5%5%13%
1661
February1st to 15thDay
14%14%6%11%8%5%6%445%18%
1588
16th to endDay
12%14%6%11%8%45%436%22%
1580
March1st to 15thDay
18%10%47%7%35%45%7%25%
1893
16th to endDay
18%10%5%8%7%34446%27%
2111
April1st to 15thDay
18%10%46%5%2445%7%30%
2145
16th to endDay
16%8%36%5%2435%7%36%
2340
May1st to 15thDay
18%6%37%6%35%35%6%32%
2331
16th to endDay
13%5%36%5%35%5%5%9%38%
2431
June1st to 15thDay
9%5%35%6%35%45%8%39%
2643
16th to endDay
9%5%26%7%37%6%7%10%33%
2640
July1st to 15thDay
7%425%5%35%6%6%8%43%
2520
16th to endDay
7%5%245%46%6%8%10%36%
2543
August1st to 15thDay
7%5%25%7%36%6%7%9%37%
2340
16th to endDay
10%5%26%5%35%5%6%9%39%
2480
September1st to 15thDay
12%5%25%435%5%5%8%38%
2010
16th to endDay
12%425%4345%6%9%38%
1829
October1st to 15thDay
13%7%35%5%43447%39%
1722
16th to endDay
20%10%36%5%34446%30%
1678
November1st to 15thDay
14%8%35%5%35%45%7%37%
1582
16th to endDay
17%10%47%7%25%5%45%28%
1533
December1st to 15thDay
16%13%6%11%6%35%445%21%
1440
16th to endDay
21%16%8%9%7%34345%16%
1437
January1st to 15thNight
21%11%5%7%7%35%345%23%
2506
16th to endNight
12%14%6%10%8%45%445%23%
2561
February1st to 15thNight
14%13%5%8%6%45%5%45%26%
2264
16th to endNight
15%10%49%6%345%36%29%
1893
March1st to 15thNight
17%9%36%5%34445%32%
2067
16th to endNight
14%7%46%5%35%446%36%
2112
April1st to 15thNight
18%8%35%44445%5%34%
1814
16th to endNight
15%6%25%43445%7%40%
1620
May1st to 15thNight
17%5%26%5%245%48%36%
1619
16th to endNight
11%5%245%35%448%44%
1682
June1st to 15thNight
8%424436%46%8%45%
1308
16th to endNight
9%5%244245%6%8%46%
1315
July1st to 15thNight
7%32342445%8%53%
1440
16th to endNight
4323325%5%6%10%51%
1623
August1st to 15thNight
5%3245%345%7%9%48%
1620
16th to endNight
9%5%24424347%52%
1719
September1st to 15thNight
10%5%24323447%50%
1938
16th to endNight
11%425%423447%49%
1837
October1st to 15thNight
15%6%34423446%43%
1907
16th to endNight
20%7%36%6%345%5%5%31%
2192
November1st to 15thNight
13%7%245%245%5%6%40%
2276
16th to endNight
20%10%36%5%245%5%5%29%
2426
December1st to 15thNight
19%12%5%7%6%34446%24%
2520
16th to endNight
21%15%6%9%6%3443418%
2781

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
66%6%11%10%4
1433
16th to endDay
71%6%9%8%4
1661
February1st to 15thDay
65%6%7%13%5%
1590
16th to endDay
62%5%9%15%6%
1580
March1st to 15thDay
58%7%10%16%6%
1893
16th to endDay
56%5%9%19%6%1
2112
April1st to 15thDay
53%410%19%11%
2145
16th to endDay
47%413%17%15%2
2340
May1st to 15thDay
51%6%9%19%10%2
2331
16th to endDay
42%6%12%23%13%2
2435
June1st to 15thDay
40%7%12%24%14%1
2643
16th to endDay
42%8%12%19%15%1
2640
July1st to 15thDay
36%6%10%24%19%2
2371
16th to endDay
38%9%14%20%14%2
2385
August1st to 15thDay
39%9%12%24%12%1
2327
16th to endDay
39%7%11%23%15%1
2480
September1st to 15thDay
40%6%13%26%13%
2010
16th to endDay
39%6%12%29%12%
1829
October1st to 15thDay
42%5%13%22%13%1
1722
16th to endDay
54%5%14%17%7%
1678
November1st to 15thDay
45%6%11%23%11%1
1582
16th to endDay
56%5%12%18%6%
1533
December1st to 15thDay
64%5%12%13%4
1440
16th to endDay
70%410%10%3
1437
January1st to 15thNight
63%5%10%14%6%
2506
16th to endNight
62%5%12%14%4
2561
February1st to 15thNight
59%7%10%14%6%
2273
16th to endNight
55%5%11%19%7%
1893
March1st to 15thNight
52%6%9%19%10%1
2067
16th to endNight
47%5%11%23%10%1
2112
April1st to 15thNight
49%5%11%19%14%
1814
16th to endNight
41%5%10%20%17%3
1620
May1st to 15thNight
45%6%10%20%14%2
1620
16th to endNight
37%6%12%23%16%3
1684
June1st to 15thNight
35%7%12%27%16%1
1308
16th to endNight
33%6%13%25%19%1
1315
July1st to 15thNight
29%5%10%29%21%2
1360
16th to endNight
26%8%16%25%19%3
1518
August1st to 15thNight
29%7%13%31%14%2
1609
16th to endNight
31%5%13%29%18%2
1719
September1st to 15thNight
33%6%10%29%18%1
1938
16th to endNight
34%411%32%15%
1837
October1st to 15thNight
39%6%11%22%18%
1907
16th to endNight
52%5%13%20%7%
2192
November1st to 15thNight
42%7%11%25%12%1
2276
16th to endNight
54%413%19%6%
2426
December1st to 15thNight
61%6%12%14%5%
2520
16th to endNight
68%5%10%10%4
2781

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%18%40%15%31
90
16th to endDay
29%15%38%12%4
96
February1st to 15thDay
20%17%48%12%1
90
16th to endDay
16%20%43%16%3
81
March1st to 15thDay
28%15%29%19%7%
183
16th to endDay
25%11%29%23%7%2
288
April1st to 15thDay
20%15%30%21%10%2
270
16th to endDay
22%10%31%15%11%8%
270
May1st to 15thDay
22%9%28%21%13%4
288
16th to endDay
15%9%27%25%15%7%
331
June1st to 15thDay
13%8%31%29%13%3
477
16th to endDay
12%8%32%27%14%5%
495
July1st to 15thDay
9%425%32%18%9%
475
16th to endDay
7%425%30%21%11%
403
August1st to 15thDay
8%219%29%21%18%
313
16th to endDay
13%417%24%21%18%
332
September1st to 15thDay
11%320%23%25%15%
315
16th to endDay
17%215%25%27%12%
259
October1st to 15thDay
14%7%26%24%20%7%
255
16th to endDay
27%12%34%20%42
190
November1st to 15thDay
11%14%32%28%11%2
90
16th to endDay
20%25%32%17%5%
75
December1st to 15thDay
21%26%33%15%3
60
16th to endDay
25%30%35%7%1
79
January1st to 15thNight
26%14%33%20%41
900
16th to endNight
19%11%35%27%5%
833
February1st to 15thNight
21%15%35%23%3
704
16th to endNight
21%12%33%27%5%
631
March1st to 15thNight
21%11%34%26%6%
720
16th to endNight
17%12%30%28%9%1
768
April1st to 15thNight
22%11%30%29%4
604
16th to endNight
18%6%33%29%10%1
540
May1st to 15thNight
19%5%27%34%11%1
540
16th to endNight
14%225%37%17%2
563
June1st to 15thNight
9%326%46%13%
393
16th to endNight
12%120%48%16%
415
July1st to 15thNight
8%120%41%25%3
510
16th to endNight
5%219%46%23%2
564
August1st to 15thNight
7%118%36%31%4
539
16th to endNight
11%116%34%32%3
573
September1st to 15thNight
12%418%31%25%6%
678
16th to endNight
13%416%32%26%6%
665
October1st to 15thNight
18%5%24%30%18%2
660
16th to endNight
25%12%32%24%4
704
November1st to 15thNight
18%10%29%24%14%1
700
16th to endNight
25%14%28%22%8%
720
December1st to 15thNight
27%12%35%19%5%
720
16th to endNight
29%11%36%20%3
954
Page generated at 2017-09-18 08:38:24. Version ac04

Copyright 2017 A. Danko


Troy Space Gazebo Clear Sky Chart | Charts Home