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Syracuse
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Syracuse clear sky chart from 2005-11-05 to 2017-05-24.

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
28%
14535
11%
45876
8%
14504
32%
14504
13%
34648

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
10%
720
5%
2506
3%
716
13%
716
4%
2147
January16th to endNight
12%
768
5%
2571
3%
768
16%
768
5%
2212
February1st to 15thNight
9%
704
6%
2287
1%
701
15%
701
5%
1966
February16th to endNight
15%
631
7%
1932
4%
631
20%
631
8%
1612
March1st to 15thNight
18%
720
9%
2076
5%
720
22%
720
11%
1663
March16th to endNight
24%
768
14%
2047
7%
768
30%
768
15%
1558
April1st to 15thNight
23%
718
11%
1796
4%
718
26%
718
16%
1418
April16th to endNight
33%
713
16%
1793
7%
713
37%
713
24%
1266
May1st to 15thNight
38%
380
17%
1460
16%
380
44%
380
17%
964
May16th to endNight
43%
360
15%
1441
15%
360
50%
360
20%
885
June1st to 15thNight
40%
330
12%
1320
12%
330
47%
330
13%
904
June16th to endNight
52%
330
11%
1320
15%
330
58%
330
22%
807
July1st to 15thNight
58%
310
14%
1240
20%
310
62%
310
25%
738
July16th to endNight
58%
348
14%
1306
16%
326
61%
326
25%
751
August1st to 15thNight
52%
475
15%
1456
11%
473
56%
473
26%
931
August16th to endNight
53%
671
18%
1721
11%
671
55%
671
32%
1136
September1st to 15thNight
48%
660
16%
1650
9%
660
51%
660
27%
1151
September16th to endNight
50%
657
20%
1796
15%
657
53%
657
28%
1198
October1st to 15thNight
33%
660
15%
1980
12%
660
38%
660
16%
1446
October16th to endNight
17%
704
7%
2161
4%
704
21%
704
10%
1732
November1st to 15thNight
22%
700
13%
2289
10%
700
28%
700
13%
1704
November16th to endNight
20%
720
11%
2520
8%
720
25%
720
10%
1943
December1st to 15thNight
11%
720
4%
2520
1%
720
15%
720
5%
2131
December16th to endNight
10%
768
2%
2688
1%
768
12%
768
4%
2385

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
17%10%47%6%3445%6%28%
46406
Night
17%11%48%6%34446%28%
46046
Cloud CoverDay
17%9%47%6%3445%7%28%
46416
Night
18%10%48%6%34446%28%
46051
TransparencyDay
55%7%11%16%8%
46094
Night
57%6%11%16%8%
45876
SeeingDay
24%14%26%20%10%4
5098
Night
25%15%25%23%9%
14536

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%16%10%11%8%36%6%4412%
1432
16th to endDay
11%16%7%13%10%5%6%5%45%13%
1650
February1st to 15thDay
15%16%6%14%11%46%34412%
1575
16th to endDay
17%14%7%15%9%4423416%
1539
March1st to 15thDay
17%15%5%11%7%34345%19%
1871
16th to endDay
18%11%46%5%23346%31%
2176
April1st to 15thDay
21%9%46%423437%31%
2152
16th to endDay
17%9%25%424446%37%
2178
May1st to 15thDay
17%7%26%5%35%446%34%
2490
16th to endDay
14%6%244345%6%9%36%
2517
June1st to 15thDay
22%7%27%4335%5%8%29%
2310
16th to endDay
17%5%25%6%35%5%7%9%32%
2310
July1st to 15thDay
11%425%6%35%6%6%8%37%
2310
16th to endDay
12%5%35%6%45%5%7%9%33%
2458
August1st to 15thDay
14%6%25%6%36%5%7%8%31%
2162
16th to endDay
14%6%35%5%45%5%5%8%33%
2118
September1st to 15thDay
18%5%25%43445%6%38%
1980
16th to endDay
16%6%345%2446%5%40%
1833
October1st to 15thDay
21%8%26%5%2435%6%33%
1650
16th to endDay
26%12%36%5%3445%6%21%
1711
November1st to 15thDay
15%10%46%6%3445%6%30%
1568
16th to endDay
20%13%5%10%7%24445%21%
1440
December1st to 15thDay
17%21%8%10%6%3333414%
1440
16th to endDay
20%20%9%12%7%3443310%
1536
January1st to 15thNight
18%17%8%11%9%35%44413%
2506
16th to endNight
14%15%7%14%9%6%5%43413%
2571
February1st to 15thNight
13%15%8%17%9%44335%13%
2285
16th to endNight
15%13%6%14%8%36%43418%
1932
March1st to 15thNight
19%12%7%10%6%2434424%
2064
16th to endNight
18%12%5%7%5%3443430%
2047
April1st to 15thNight
21%10%36%5%35%446%28%
1796
16th to endNight
19%7%34323446%40%
1793
May1st to 15thNight
19%7%25%5%2435%7%36%
1460
16th to endNight
12%5%25%42446%8%41%
1439
June1st to 15thNight
21%5%35%5%25%5%6%7%31%
1320
16th to endNight
14%425%5%2446%7%40%
1320
July1st to 15thNight
8%235%436%5%6%9%44%
1320
16th to endNight
11%41443445%8%45%
1402
August1st to 15thNight
9%425%6%36%6%6%7%42%
1466
16th to endNight
11%5%24434447%45%
1721
September1st to 15thNight
18%4245%25%446%42%
1650
16th to endNight
16%414325%45%6%43%
1796
October1st to 15thNight
24%7%245%35%446%31%
1980
16th to endNight
28%11%38%5%23435%22%
2161
November1st to 15thNight
19%14%36%5%23446%28%
2289
16th to endNight
18%15%5%8%5%24446%25%
2520
December1st to 15thNight
21%17%7%10%5%25%43416%
2520
16th to endNight
20%19%8%11%7%3434411%
2688

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%16%9%12%7%36%5%4412%
1432
16th to endDay
12%16%7%13%11%5%6%5%45%13%
1650
February1st to 15thDay
15%16%6%14%11%45%44412%
1575
16th to endDay
18%14%6%14%9%4433416%
1539
March1st to 15thDay
18%15%5%10%8%35%345%19%
1882
16th to endDay
18%11%46%5%33445%32%
2175
April1st to 15thDay
21%9%46%424436%31%
2152
16th to endDay
17%9%25%42335%6%37%
2178
May1st to 15thDay
18%6%27%5%35%446%35%
2490
16th to endDay
14%5%25%4345%6%9%36%
2517
June1st to 15thDay
23%6%36%5%2445%8%29%
2310
16th to endDay
17%5%25%5%35%6%6%9%32%
2310
July1st to 15thDay
10%5%25%5%46%6%6%9%36%
2310
16th to endDay
13%5%25%5%46%6%7%9%33%
2458
August1st to 15thDay
14%5%25%6%45%6%7%8%31%
2162
16th to endDay
15%5%35%5%46%5%5%9%33%
2118
September1st to 15thDay
17%5%25%43445%7%38%
1980
16th to endDay
15%6%25%5%3445%5%40%
1833
October1st to 15thDay
21%8%35%6%23447%33%
1650
16th to endDay
25%12%36%5%34446%21%
1711
November1st to 15thDay
16%10%46%6%35%45%6%30%
1568
16th to endDay
20%14%5%9%7%34345%21%
1440
December1st to 15thDay
16%22%8%10%6%3434414%
1440
16th to endDay
21%19%9%11%7%3444310%
1536
January1st to 15thNight
18%17%8%10%8%35%43413%
2506
16th to endNight
15%15%8%13%10%5%5%33414%
2571
February1st to 15thNight
13%15%8%16%9%35%335%13%
2278
16th to endNight
16%13%6%14%8%36%44418%
1932
March1st to 15thNight
20%11%7%10%7%2434423%
2076
16th to endNight
19%11%5%7%5%2433431%
2047
April1st to 15thNight
21%10%46%5%35%446%28%
1796
16th to endNight
19%7%24323445%40%
1793
May1st to 15thNight
19%7%26%42436%6%36%
1460
16th to endNight
12%5%25%42446%7%41%
1439
June1st to 15thNight
21%5%35%5%345%5%7%31%
1320
16th to endNight
14%5%15%4345%6%7%40%
1320
July1st to 15thNight
7%325%5%37%46%9%44%
1320
16th to endNight
11%41443445%9%45%
1402
August1st to 15thNight
10%325%6%36%5%6%7%42%
1466
16th to endNight
12%5%244345%5%7%45%
1721
September1st to 15thNight
18%4245%24446%42%
1650
16th to endNight
16%5%2442445%6%43%
1796
October1st to 15thNight
25%7%244345%45%31%
1980
16th to endNight
28%11%37%5%24336%22%
2161
November1st to 15thNight
19%13%36%6%24346%29%
2289
16th to endNight
18%15%5%8%5%33446%25%
2520
December1st to 15thNight
21%16%7%9%5%25%44416%
2520
16th to endNight
21%17%9%11%7%3434411%
2688

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
74%6%8%7%3
1433
16th to endDay
73%5%11%6%2
1650
February1st to 15thDay
76%5%6%9%1
1577
16th to endDay
74%47%10%3
1539
March1st to 15thDay
67%5%11%10%5%
1882
16th to endDay
54%410%15%12%
2176
April1st to 15thDay
54%5%9%19%9%1
2152
16th to endDay
47%5%9%20%15%1
2178
May1st to 15thDay
50%6%10%19%12%
2490
16th to endDay
43%9%15%18%12%
2521
June1st to 15thDay
53%7%10%18%8%
2310
16th to endDay
46%9%12%19%10%
2310
July1st to 15thDay
42%9%10%25%11%
2161
16th to endDay
43%8%16%21%9%
2291
August1st to 15thDay
45%10%13%19%10%
2148
16th to endDay
45%7%13%22%10%
2118
September1st to 15thDay
44%8%10%23%11%
1980
16th to endDay
44%6%9%25%13%1
1833
October1st to 15thDay
50%5%12%20%9%
1650
16th to endDay
62%8%12%12%4
1711
November1st to 15thDay
53%7%12%15%8%1
1568
16th to endDay
65%5%12%12%4
1440
December1st to 15thDay
73%5%10%7%2
1440
16th to endDay
79%5%7%5%1
1536
January1st to 15thNight
73%6%8%8%3
2506
16th to endNight
75%48%9%2
2571
February1st to 15thNight
74%5%6%9%3
2287
16th to endNight
69%5%10%9%4
1932
March1st to 15thNight
64%411%13%4
2076
16th to endNight
56%49%16%10%1
2047
April1st to 15thNight
57%7%8%15%9%1
1796
16th to endNight
46%5%10%18%16%2
1793
May1st to 15thNight
47%6%10%19%13%2
1460
16th to endNight
39%8%14%22%13%1
1441
June1st to 15thNight
51%6%12%21%8%
1320
16th to endNight
40%6%13%22%15%
1320
July1st to 15thNight
34%9%13%27%13%1
1240
16th to endNight
36%6%15%26%13%2
1306
August1st to 15thNight
38%7%16%26%9%
1456
16th to endNight
37%7%13%28%13%
1721
September1st to 15thNight
42%7%12%23%12%1
1650
16th to endNight
40%6%12%26%13%1
1796
October1st to 15thNight
53%6%10%16%13%
1980
16th to endNight
64%5%13%11%4
2161
November1st to 15thNight
57%6%11%14%7%2
2289
16th to endNight
60%6%12%14%5%
2520
December1st to 15thNight
71%6%11%8%2
2520
16th to endNight
77%6%8%6%1
2688

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
26%31%26%6%8%
60
16th to endDay
30%26%37%41
83
February1st to 15thDay
34%33%30%2
90
16th to endDay
31%25%26%14%1
198
March1st to 15thDay
32%19%25%17%4
270
16th to endDay
29%18%25%19%5%1
288
April1st to 15thDay
30%20%24%15%7%1
270
16th to endDay
27%12%24%20%9%6%
270
May1st to 15thDay
26%15%25%17%12%2
288
16th to endDay
16%11%35%21%11%3
302
June1st to 15thDay
28%11%21%21%14%3
255
16th to endDay
20%10%28%26%12%1
255
July1st to 15thDay
12%6%30%28%16%5%
245
16th to endDay
12%5%29%31%15%5%
270
August1st to 15thDay
14%10%24%26%15%8%
253
16th to endDay
14%6%26%17%18%15%
268
September1st to 15thDay
15%10%14%25%21%12%
255
16th to endDay
15%11%24%24%14%11%
254
October1st to 15thDay
23%12%23%21%17%2
255
16th to endDay
43%12%26%13%3
263
November1st to 15thDay
26%16%26%23%6%1
222
16th to endDay
36%15%33%15%
60
December1st to 15thDay
30%25%23%15%5%1
60
16th to endDay
39%26%29%4
64
January1st to 15thNight
30%24%28%12%3
720
16th to endNight
24%24%31%15%3
768
February1st to 15thNight
26%22%35%14%1
704
16th to endNight
26%24%28%17%3
631
March1st to 15thNight
29%20%28%19%2
720
16th to endNight
25%20%25%21%7%
768
April1st to 15thNight
29%17%26%23%2
718
16th to endNight
24%14%24%25%9%
713
May1st to 15thNight
22%11%22%33%9%
380
16th to endNight
12%8%31%32%14%
361
June1st to 15thNight
23%8%19%34%13%
330
16th to endNight
16%421%44%12%
330
July1st to 15thNight
10%320%41%20%2
310
16th to endNight
13%120%44%17%2
348
August1st to 15thNight
13%424%34%21%2
475
16th to endNight
16%321%29%26%2
671
September1st to 15thNight
19%5%20%30%21%2
660
16th to endNight
17%9%18%28%22%3
657
October1st to 15thNight
29%11%20%21%15%
660
16th to endNight
35%17%23%20%3
704
November1st to 15thNight
28%16%26%19%7%
700
16th to endNight
28%21%25%17%6%
720
December1st to 15thNight
34%25%25%13%1
720
16th to endNight
33%23%25%14%2
768
Page generated at 2017-05-25 13:27:30. Version ac04

Copyright 2017 A. Danko


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