Baddeck
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Baddeck clear sky chart from 2005-11-05 to 2017-12-01.

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
20%
15545
9%
47802
4%
15500
25%
15500
10%
37851

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
9%
750
5%
2506
1%
746
14%
746
4%
2177
January16th to endNight
8%
795
5%
2661
1%
795
13%
795
4%
2285
February1st to 15thNight
13%
704
5%
2286
1%
701
17%
701
5%
1902
February16th to endNight
16%
631
8%
1955
2%
631
21%
631
7%
1602
March1st to 15thNight
18%
717
12%
2106
4%
717
26%
717
11%
1636
March16th to endNight
20%
687
12%
2031
4%
687
28%
687
11%
1561
April1st to 15thNight
18%
539
11%
1796
6%
539
25%
539
10%
1351
April16th to endNight
20%
540
14%
1689
8%
540
27%
540
15%
1222
May1st to 15thNight
26%
540
11%
1440
6%
540
29%
540
15%
1102
May16th to endNight
23%
561
10%
1496
3%
560
27%
560
15%
1150
June1st to 15thNight
20%
540
5%
1440
2%
540
22%
540
12%
1157
June16th to endNight
25%
540
6%
1440
2%
540
27%
540
15%
1128
July1st to 15thNight
34%
510
7%
1360
4%
510
35%
510
21%
1002
July16th to endNight
32%
565
9%
1419
6%
532
33%
532
15%
1129
August1st to 15thNight
38%
539
10%
1492
6%
535
40%
535
18%
1114
August16th to endNight
41%
573
14%
1860
12%
573
44%
573
19%
1291
September1st to 15thNight
31%
540
12%
1800
8%
540
38%
540
17%
1246
September16th to endNight
26%
575
18%
1957
12%
575
36%
575
17%
1332
October1st to 15thNight
27%
720
12%
2160
5%
720
33%
720
16%
1561
October16th to endNight
17%
795
10%
2411
4%
795
21%
795
10%
1914
November1st to 15thNight
18%
805
8%
2548
3%
805
21%
805
9%
2061
November16th to endNight
16%
825
7%
2730
3%
825
20%
825
6%
2256
December1st to 15thNight
9%
754
4%
2531
0%
754
13%
754
3%
2235
December16th to endNight
8%
800
3%
2688
0%
800
10%
800
2%
2437

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
22%10%47%6%35%446%23%
48637
Night
22%9%47%6%35%5%5%6%23%
47973
TransparencyDay
61%7%10%14%6%
48326
Night
61%7%10%14%5%
47802
SeeingDay
30%20%26%15%6%1
8013
Night
28%19%26%19%5%
15548

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%12%6%11%10%5%6%5%5%5%14%
1432
16th to endDay
17%13%6%13%9%47%45%411%
1563
February1st to 15thDay
15%13%412%10%47%5%5%6%14%
1575
16th to endDay
13%15%6%9%8%36%446%20%
1516
March1st to 15thDay
16%13%5%7%8%47%445%22%
1844
16th to endDay
17%12%5%9%7%35%44424%
2193
April1st to 15thDay
22%14%36%5%24446%24%
2153
16th to endDay
23%11%36%424346%29%
2268
May1st to 15thDay
27%8%45%6%34445%26%
2512
16th to endDay
24%10%36%5%345%46%25%
2618
June1st to 15thDay
29%9%26%5%34446%22%
2520
16th to endDay
27%7%36%5%2445%6%26%
2520
July1st to 15thDay
19%6%35%5%245%5%8%32%
2520
16th to endDay
25%7%36%5%26%5%5%8%23%
2653
August1st to 15thDay
23%8%36%5%35%447%25%
2456
16th to endDay
20%8%35%435%46%7%31%
2342
September1st to 15thDay
22%6%35%5%24447%31%
2160
16th to endDay
19%6%25%5%35%45%8%32%
2001
October1st to 15thDay
19%7%37%7%4445%7%28%
1800
16th to endDay
24%10%49%6%45%5%45%17%
1812
November1st to 15thDay
27%12%48%6%4443419%
1640
16th to endDay
22%14%5%8%7%45%45%6%14%
1560
December1st to 15thDay
27%13%8%9%9%45%3447%
1443
16th to endDay
21%15%8%13%11%46%3336%
1536
January1st to 15thNight
18%11%6%9%10%5%8%6%5%5%11%
2506
16th to endNight
19%12%6%10%9%48%6%6%5%12%
2661
February1st to 15thNight
16%12%410%8%48%5%5%5%17%
2285
16th to endNight
14%13%6%9%7%5%6%5%5%6%19%
1955
March1st to 15thNight
17%9%47%8%45%45%7%25%
2093
16th to endNight
18%10%5%6%6%36%445%27%
2031
April1st to 15thNight
24%10%46%6%33445%26%
1796
16th to endNight
25%7%34423335%34%
1689
May1st to 15thNight
29%8%34423346%29%
1440
16th to endNight
21%9%37%5%35%35%7%27%
1494
June1st to 15thNight
30%8%35%6%34346%23%
1440
16th to endNight
26%8%345%25%445%27%
1440
July1st to 15thNight
19%6%25%5%45%5%5%7%32%
1440
16th to endNight
26%7%25%5%25%6%6%5%25%
1515
August1st to 15thNight
22%5%25%5%35%5%5%5%32%
1503
16th to endNight
18%6%244245%6%9%35%
1860
September1st to 15thNight
22%5%14425%45%6%36%
1800
16th to endNight
20%6%244245%5%6%36%
1957
October1st to 15thNight
21%6%25%5%35%447%32%
2160
16th to endNight
25%9%25%6%35%5%6%6%22%
2411
November1st to 15thNight
23%9%38%7%35%46%6%20%
2548
16th to endNight
24%11%46%6%46%5%6%7%17%
2730
December1st to 15thNight
26%12%5%9%7%46%5%5%6%11%
2531
16th to endNight
23%14%7%12%10%45%4449%
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
72%7%8%8%2
1433
16th to endDay
75%5%8%8%2
1563
February1st to 15thDay
70%8%7%9%3
1578
16th to endDay
64%7%9%10%6%
1516
March1st to 15thDay
63%5%9%14%6%
1854
16th to endDay
63%5%9%13%6%
2193
April1st to 15thDay
60%6%9%11%10%1
2153
16th to endDay
58%7%9%14%9%1
2268
May1st to 15thDay
59%7%9%16%6%1
2512
16th to endDay
58%8%9%16%7%
2622
June1st to 15thDay
62%8%9%12%6%
2520
16th to endDay
57%8%10%16%7%
2520
July1st to 15thDay
46%10%14%20%8%
2372
16th to endDay
57%9%11%16%4
2486
August1st to 15thDay
56%9%11%17%5%
2442
16th to endDay
49%9%15%19%5%
2342
September1st to 15thDay
52%6%12%20%7%
2160
16th to endDay
49%6%11%21%9%
2001
October1st to 15thDay
54%7%11%17%8%
1800
16th to endDay
67%7%9%12%3
1812
November1st to 15thDay
69%5%9%12%2
1640
16th to endDay
70%5%11%7%3
1560
December1st to 15thDay
80%5%6%5%
1443
16th to endDay
82%5%5%41
1536
January1st to 15thNight
74%7%8%7%2
2506
16th to endNight
73%6%7%10%2
2661
February1st to 15thNight
68%7%10%9%3
2286
16th to endNight
66%7%9%11%4
1955
March1st to 15thNight
59%6%8%16%8%
2106
16th to endNight
59%5%9%15%8%1
2031
April1st to 15thNight
59%5%9%14%10%
1796
16th to endNight
53%5%8%16%13%1
1689
May1st to 15thNight
56%6%10%19%7%
1440
16th to endNight
58%5%10%18%6%
1496
June1st to 15thNight
63%5%10%15%4
1440
16th to endNight
59%6%10%14%9%
1440
July1st to 15thNight
48%8%15%18%9%
1360
16th to endNight
57%9%11%16%4
1419
August1st to 15thNight
53%6%15%18%5%
1492
16th to endNight
43%11%15%23%5%
1860
September1st to 15thNight
47%8%12%22%9%
1800
16th to endNight
47%7%11%24%8%
1957
October1st to 15thNight
50%7%13%20%7%
2160
16th to endNight
60%7%10%16%4
2411
November1st to 15thNight
63%8%12%12%3
2548
16th to endNight
66%8%12%9%3
2730
December1st to 15thNight
74%8%9%6%1
2531
16th to endNight
81%5%5%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
25%30%30%12%
240
16th to endDay
26%31%27%12%2
256
February1st to 15thDay
25%30%27%14%1
236
16th to endDay
29%29%20%13%6%
212
March1st to 15thDay
21%32%23%13%9%
250
16th to endDay
24%33%23%11%42
288
April1st to 15thDay
29%31%23%10%4
270
16th to endDay
30%23%27%14%3
315
May1st to 15thDay
38%17%18%15%7%3
468
16th to endDay
29%16%29%16%6%1
519
June1st to 15thDay
38%15%24%15%4
495
16th to endDay
33%13%29%15%6%2
495
July1st to 15thDay
24%9%32%23%9%1
475
16th to endDay
32%12%24%21%9%
514
August1st to 15thDay
29%7%29%21%10%1
429
16th to endDay
26%12%30%21%7%2
332
September1st to 15thDay
26%18%34%14%5%
315
16th to endDay
25%16%29%18%8%1
284
October1st to 15thDay
23%18%31%15%7%3
270
16th to endDay
30%24%24%12%5%2
288
November1st to 15thDay
31%23%23%12%6%2
280
16th to endDay
33%25%22%13%4
285
December1st to 15thDay
39%26%21%7%3
241
16th to endDay
30%34%20%10%11
256
January1st to 15thNight
25%31%27%12%2
750
16th to endNight
26%33%25%11%3
795
February1st to 15thNight
27%25%26%17%2
704
16th to endNight
24%26%26%17%5%
631
March1st to 15thNight
22%25%29%18%4
720
16th to endNight
24%26%23%17%6%1
687
April1st to 15thNight
29%19%25%22%3
539
16th to endNight
30%14%29%18%6%
540
May1st to 15thNight
33%14%22%19%9%1
540
16th to endNight
25%16%27%22%7%
561
June1st to 15thNight
33%11%29%20%4
540
16th to endNight
31%8%30%23%6%
540
July1st to 15thNight
24%6%30%31%7%
510
16th to endNight
28%7%26%28%7%
565
August1st to 15thNight
27%6%21%33%11%1
539
16th to endNight
23%6%24%34%10%
573
September1st to 15thNight
24%10%29%25%10%
540
16th to endNight
25%13%29%22%8%
575
October1st to 15thNight
27%14%25%23%8%1
720
16th to endNight
30%21%25%16%5%
795
November1st to 15thNight
31%17%26%17%41
805
16th to endNight
30%24%23%15%5%
825
December1st to 15thNight
35%28%21%10%4
754
16th to endNight
34%28%22%10%31
800
Page generated at 2017-12-02 10:14:22. Version ac04

Copyright 2017 A. Danko


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