Albany
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Albany 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
55%
16020
23%
48382
18%
15976
61%
15976
30%
29736

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
36%
765
22%
2472
12%
761
49%
761
26%
1508
January16th to endNight
35%
768
25%
2394
16%
768
46%
768
26%
1489
February1st to 15thNight
40%
704
26%
2108
14%
700
52%
700
30%
1277
February16th to endNight
38%
631
27%
1893
13%
631
50%
631
30%
1148
March1st to 15thNight
43%
720
28%
2049
15%
720
54%
720
34%
1226
March16th to endNight
48%
768
24%
2112
14%
768
55%
768
35%
1252
April1st to 15thNight
52%
675
26%
1933
19%
675
58%
675
36%
1123
April16th to endNight
59%
540
30%
1734
23%
540
67%
540
40%
903
May1st to 15thNight
61%
539
25%
1620
20%
539
66%
539
36%
931
May16th to endNight
70%
561
23%
1682
18%
561
73%
561
35%
1013
June1st to 15thNight
70%
540
15%
1620
13%
540
70%
540
26%
1079
June16th to endNight
73%
540
15%
1620
14%
540
73%
540
27%
1074
July1st to 15thNight
72%
510
11%
1530
11%
510
72%
510
24%
1042
July16th to endNight
74%
564
13%
1595
13%
531
74%
531
26%
1086
August1st to 15thNight
70%
539
12%
1700
13%
536
70%
536
22%
1177
August16th to endNight
68%
579
15%
1916
18%
579
68%
579
19%
1351
September1st to 15thNight
62%
720
14%
1980
12%
720
63%
720
23%
1398
September16th to endNight
63%
717
22%
1980
19%
717
65%
717
27%
1320
October1st to 15thNight
62%
720
29%
1980
26%
720
66%
720
40%
1163
October16th to endNight
57%
768
35%
2292
30%
768
65%
768
39%
1266
November1st to 15thNight
59%
760
30%
2398
26%
760
67%
760
40%
1261
November16th to endNight
48%
780
29%
2535
22%
780
59%
780
34%
1402
December1st to 15thNight
45%
780
25%
2535
20%
780
54%
780
29%
1510
December16th to endNight
41%
832
23%
2704
19%
832
49%
832
24%
1737

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
11%5%25%5%35%5%6%7%41%
48942
Night
10%42443445%8%45%
48585
TransparencyDay
38%7%11%17%17%7%
48643
Night
35%6%11%17%18%9%
48388
SeeingDay
11%315%23%26%19%
5843
Night
12%420%32%25%4
16023

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
12%5%35%434445%45%
1710
16th to endDay
15%5%25%324446%46%
1827
February1st to 15thDay
13%5%245%2435%5%45%
1750
16th to endDay
15%5%24323345%48%
1580
March1st to 15thDay
11%6%14424348%48%
1911
16th to endDay
12%6%23334346%48%
2111
April1st to 15thDay
12%5%245%25%45%6%46%
2025
16th to endDay
8%3145%34447%53%
2226
May1st to 15thDay
8%4245%3445%8%47%
2331
16th to endDay
5%325%7%36%5%7%8%42%
2431
June1st to 15thDay
8%5%36%6%47%7%7%9%32%
2340
16th to endDay
6%316%8%48%7%8%10%33%
2340
July1st to 15thDay
8%5%38%8%5%7%7%8%10%27%
2340
16th to endDay
7%427%7%5%7%7%9%11%27%
2465
August1st to 15thDay
11%6%26%7%48%8%9%11%23%
2245
16th to endDay
11%6%28%8%46%8%6%9%27%
2271
September1st to 15thDay
9%5%36%8%46%6%7%8%32%
1980
16th to endDay
12%5%26%6%35%36%7%39%
1980
October1st to 15thDay
12%414333446%50%
1980
16th to endDay
8%313323335%61%
1930
November1st to 15thDay
9%414323345%56%
1787
16th to endDay
11%4145%13245%54%
1755
December1st to 15thDay
15%6%34423446%44%
1755
16th to endDay
20%6%35%424345%38%
1872
January1st to 15thNight
13%5%35%434446%45%
2472
16th to endNight
15%6%25%324345%46%
2394
February1st to 15thNight
13%5%24323445%50%
2103
16th to endNight
13%5%24324446%48%
1893
March1st to 15thNight
10%424424446%51%
2049
16th to endNight
10%424423346%53%
2112
April1st to 15thNight
10%41342335%7%52%
1933
16th to endNight
7%31332446%8%54%
1734
May1st to 15thNight
6%3244345%5%8%51%
1619
16th to endNight
4325%5%35%5%6%8%49%
1682
June1st to 15thNight
7%436%5%47%6%8%12%34%
1620
16th to endNight
5%426%5%36%7%8%11%37%
1620
July1st to 15thNight
6%5%35%6%36%7%10%12%32%
1620
16th to endNight
5%425%5%47%7%9%12%34%
1703
August1st to 15thNight
7%425%7%47%7%9%13%30%
1711
16th to endNight
9%5%26%6%46%8%7%10%31%
1916
September1st to 15thNight
10%6%36%7%36%5%7%10%33%
1980
16th to endNight
8%6%25%6%45%5%6%9%38%
1980
October1st to 15thNight
9%41442335%8%52%
1980
16th to endNight
9%42332323459%
2292
November1st to 15thNight
8%313313347%57%
2398
16th to endNight
12%323323345%54%
2535
December1st to 15thNight
13%5%2442435%6%47%
2535
16th to endNight
15%7%35%42345%6%41%
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
39%48%15%21%10%
1711
16th to endDay
39%46%15%24%10%
1827
February1st to 15thDay
39%36%15%23%11%
1752
16th to endDay
38%36%16%24%10%
1580
March1st to 15thDay
34%47%20%23%9%
1911
16th to endDay
36%410%17%22%8%
2112
April1st to 15thDay
38%47%19%21%8%
2025
16th to endDay
30%5%9%23%23%8%
2226
May1st to 15thDay
32%5%11%20%21%7%
2331
16th to endDay
34%7%13%24%14%4
2435
June1st to 15thDay
41%10%16%20%9%
2340
16th to endDay
39%11%17%17%11%1
2340
July1st to 15thDay
45%12%20%14%5%
2201
16th to endDay
44%14%18%16%5%
2310
August1st to 15thDay
48%12%19%14%4
2232
16th to endDay
49%11%15%13%7%1
2271
September1st to 15thDay
45%10%15%11%12%3
1980
16th to endDay
41%6%11%17%18%4
1980
October1st to 15thDay
33%5%9%18%21%11%
1980
16th to endDay
26%35%15%31%17%
1930
November1st to 15thDay
28%47%18%26%14%
1787
16th to endDay
32%37%16%25%14%
1755
December1st to 15thDay
39%5%10%15%18%9%
1755
16th to endDay
48%37%19%12%7%
1872
January1st to 15thNight
40%37%15%23%9%
2472
16th to endNight
40%35%14%24%11%
2394
February1st to 15thNight
37%26%15%22%15%
2112
16th to endNight
36%46%15%20%16%
1893
March1st to 15thNight
32%5%7%20%21%11%
2049
16th to endNight
32%310%17%24%11%
2112
April1st to 15thNight
31%48%18%23%13%
1933
16th to endNight
25%5%12%23%22%10%
1734
May1st to 15thNight
28%7%11%18%21%11%
1620
16th to endNight
29%9%14%22%16%7%
1684
June1st to 15thNight
36%12%17%22%10%1
1620
16th to endNight
37%11%19%18%11%2
1620
July1st to 15thNight
36%14%24%16%6%1
1530
16th to endNight
37%12%22%18%6%1
1595
August1st to 15thNight
39%14%25%15%4
1700
16th to endNight
43%13%17%15%8%1
1916
September1st to 15thNight
43%10%16%12%13%3
1980
16th to endNight
39%8%13%13%18%5%
1980
October1st to 15thNight
29%5%11%20%19%13%
1980
16th to endNight
30%2413%29%19%
2292
November1st to 15thNight
26%48%17%27%16%
2398
16th to endNight
31%47%17%21%18%
2535
December1st to 15thNight
36%410%18%20%8%
2535
16th to endNight
43%5%7%21%15%8%
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
12%14%39%20%5%7%
123
16th to endDay
18%16%38%15%10%
96
February1st to 15thDay
8%21%36%21%11%1
90
16th to endDay
14%9%38%30%6%
81
March1st to 15thDay
9%8%35%30%14%
201
16th to endDay
13%426%33%19%2
288
April1st to 15thDay
14%9%20%29%22%4
270
16th to endDay
10%218%29%27%11%
270
May1st to 15thDay
10%421%28%23%11%
288
16th to endDay
7%29%25%31%24%
331
June1st to 15thDay
13%5%17%32%30%
315
16th to endDay
10%318%33%35%
315
July1st to 15thDay
9%310%32%43%
305
16th to endDay
7%311%31%45%
326
August1st to 15thDay
13%1414%32%33%
313
16th to endDay
9%6%12%30%41%
332
September1st to 15thDay
13%8%19%28%28%
315
16th to endDay
16%7%21%35%19%
314
October1st to 15thDay
13%15%30%26%12%
315
16th to endDay
8%420%31%28%6%
336
November1st to 15thDay
12%220%32%25%5%
205
16th to endDay
48%25%34%20%6%
135
December1st to 15thDay
21%7%27%27%13%2
135
16th to endDay
28%9%22%25%13%1
144
January1st to 15thNight
13%9%34%31%9%
765
16th to endNight
19%8%31%31%9%
768
February1st to 15thNight
15%9%29%36%9%
704
16th to endNight
14%7%35%36%5%
631
March1st to 15thNight
11%8%31%37%11%
720
16th to endNight
12%6%28%34%16%1
768
April1st to 15thNight
12%5%25%37%17%
675
16th to endNight
7%226%37%25%1
540
May1st to 15thNight
8%221%39%25%2
540
16th to endNight
7%12%38%34%5%
563
June1st to 15thNight
7%8%33%39%9%
540
16th to endNight
7%426%47%13%
540
July1st to 15thNight
9%324%41%19%
510
16th to endNight
7%423%47%15%
564
August1st to 15thNight
10%419%51%12%
539
16th to endNight
12%15%21%42%16%
579
September1st to 15thNight
12%28%25%39%11%
720
16th to endNight
11%111%35%37%3
717
October1st to 15thNight
12%115%36%29%4
720
16th to endNight
11%322%32%27%2
768
November1st to 15thNight
10%420%39%22%2
760
16th to endNight
12%6%29%30%20%
780
December1st to 15thNight
15%329%34%14%2
780
16th to endNight
18%6%25%33%14%1
832
Page generated at 2018-01-12 22:01:35. Version ac04

Copyright 2018 A. Danko


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