Domaine Saint-Bernard
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Domaine Saint-Bernard clear sky chart from 2005-11-05 to

2017-09-12
.

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
27%
14572
11%
46790
7%
14540
33%
14540
14%
34508

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
14%
720
6%
2506
2%
716
19%
716
6%
2081
January16th to endNight
19%
768
9%
2688
4%
768
26%
768
9%
2081
February1st to 15thNight
16%
704
10%
2299
3%
701
24%
701
10%
1790
February16th to endNight
19%
631
10%
1922
5%
631
26%
631
11%
1485
March1st to 15thNight
18%
720
12%
2146
7%
720
25%
720
12%
1657
March16th to endNight
28%
768
19%
2001
7%
768
36%
768
21%
1399
April1st to 15thNight
24%
718
15%
1796
5%
718
29%
718
18%
1346
April16th to endNight
26%
627
16%
1707
6%
627
34%
627
20%
1200
May1st to 15thNight
31%
360
15%
1440
12%
360
41%
360
15%
992
May16th to endNight
28%
375
12%
1497
9%
374
39%
374
16%
1010
June1st to 15thNight
32%
360
6%
1440
6%
360
38%
360
12%
1033
June16th to endNight
45%
360
7%
1440
10%
360
47%
360
16%
960
July1st to 15thNight
51%
340
10%
1360
15%
340
55%
340
23%
798
July16th to endNight
51%
376
12%
1418
15%
354
54%
354
22%
866
August1st to 15thNight
51%
374
12%
1445
13%
372
55%
372
19%
945
August16th to endNight
48%
735
16%
1881
9%
735
52%
735
30%
1240
September1st to 15thNight
42%
707
12%
1768
5%
707
45%
707
26%
1251
September16th to endNight
43%
657
18%
1786
11%
657
47%
657
28%
1178
October1st to 15thNight
29%
660
16%
1974
9%
660
37%
660
16%
1423
October16th to endNight
23%
704
10%
2241
6%
704
28%
704
11%
1760
November1st to 15thNight
25%
700
16%
2307
10%
700
34%
700
13%
1704
November16th to endNight
19%
720
10%
2520
7%
720
23%
720
8%
1993
December1st to 15thNight
14%
720
6%
2520
2%
720
19%
720
6%
2087
December16th to endNight
10%
768
9%
2688
3%
768
17%
768
5%
2229

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
20%11%46%6%34446%27%
47879
Night
18%11%47%5%34445%28%
46959
Cloud CoverDay
20%11%46%6%34446%28%
47888
Night
18%11%47%5%34445%29%
46965
TransparencyDay
56%6%10%16%8%1
47566
Night
55%5%11%17%8%
46790
SeeingDay
27%14%27%19%8%2
5487
Night
24%14%27%23%9%
14572

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
21%18%6%12%8%2332316%
1432
16th to endDay
12%15%8%9%8%3445%6%19%
1536
February1st to 15thDay
10%17%6%13%9%35%336%20%
1563
16th to endDay
14%19%6%10%7%3435%422%
1550
March1st to 15thDay
17%13%6%9%5%25%435%25%
1802
16th to endDay
16%9%46%6%34347%33%
2223
April1st to 15thDay
22%13%5%5%422245%29%
2152
16th to endDay
22%9%35%5%2444433%
2262
May1st to 15thDay
24%9%36%5%24345%28%
2511
16th to endDay
21%9%36%5%35%346%29%
2618
June1st to 15thDay
24%8%36%5%45%45%6%25%
2520
16th to endDay
22%7%26%5%45%6%5%7%26%
2520
July1st to 15thDay
18%6%35%6%35%5%5%7%31%
2520
16th to endDay
16%8%35%6%35%5%6%7%29%
2654
August1st to 15thDay
18%8%37%6%46%6%5%6%27%
2503
16th to endDay
15%5%25%5%45%5%5%8%36%
2309
September1st to 15thDay
22%6%25%5%24446%33%
2112
16th to endDay
22%6%24222346%40%
1843
October1st to 15thDay
27%10%24424346%28%
1654
16th to endDay
30%15%47%5%2333419%
1631
November1st to 15thDay
18%12%46%6%25%5%46%26%
1548
16th to endDay
25%16%5%6%5%2342423%
1440
December1st to 15thDay
24%21%6%7%433345%15%
1440
16th to endDay
22%18%7%9%7%2443216%
1536
January1st to 15thNight
19%19%7%10%8%2444414%
2506
16th to endNight
11%17%7%8%8%45%5%5%5%19%
2688
February1st to 15thNight
10%17%7%10%8%45%435%22%
2297
16th to endNight
16%13%6%11%6%24445%22%
1922
March1st to 15thNight
20%13%48%6%35%345%25%
2133
16th to endNight
14%10%36%5%25%345%37%
2001
April1st to 15thNight
26%9%45%423335%32%
1796
16th to endNight
20%9%25%423446%36%
1707
May1st to 15thNight
21%8%35%5%24435%34%
1440
16th to endNight
20%7%35%5%25%346%35%
1495
June1st to 15thNight
19%8%47%6%2446%7%28%
1440
16th to endNight
18%6%24426%5%5%6%35%
1440
July1st to 15thNight
13%433335%46%8%42%
1440
16th to endNight
11%5%25%5%25%5%7%8%41%
1514
August1st to 15thNight
13%5%345%35%6%6%8%37%
1455
16th to endNight
12%5%245%2346%7%44%
1881
September1st to 15thNight
20%7%24414446%39%
1768
16th to endNight
18%5%25%323347%44%
1786
October1st to 15thNight
21%8%37%6%2434433%
1974
16th to endNight
30%12%36%5%2343423%
2241
November1st to 15thNight
21%10%46%5%34446%27%
2307
16th to endNight
24%16%6%7%5%3433420%
2520
December1st to 15thNight
22%18%7%9%6%2334416%
2520
16th to endNight
21%20%6%8%6%3433315%
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
21%18%6%11%8%3332416%
1432
16th to endDay
12%15%8%9%8%3445%6%20%
1536
February1st to 15thDay
10%17%6%12%9%35%436%20%
1563
16th to endDay
14%19%6%9%7%3444422%
1550
March1st to 15thDay
17%13%6%9%6%34345%25%
1812
16th to endDay
16%9%46%6%23447%33%
2222
April1st to 15thDay
22%14%45%5%22345%30%
2152
16th to endDay
22%9%35%5%2344433%
2262
May1st to 15thDay
24%9%36%5%24446%28%
2511
16th to endDay
23%8%36%6%35%346%29%
2618
June1st to 15thDay
24%7%36%5%36%5%5%6%25%
2520
16th to endDay
22%6%26%6%35%5%5%7%26%
2520
July1st to 15thDay
18%6%35%6%35%5%6%8%31%
2520
16th to endDay
16%7%35%6%36%5%6%7%30%
2654
August1st to 15thDay
17%7%35%6%35%6%5%6%30%
2503
16th to endDay
14%5%25%5%35%5%5%7%39%
2309
September1st to 15thDay
22%6%35%43445%6%33%
2112
16th to endDay
23%6%23323346%40%
1843
October1st to 15thDay
26%11%24423446%29%
1654
16th to endDay
30%15%27%5%2333419%
1631
November1st to 15thDay
18%12%46%5%25%446%27%
1548
16th to endDay
25%16%5%6%5%2333424%
1440
December1st to 15thDay
24%21%6%6%433335%16%
1440
16th to endDay
22%18%7%9%7%2433316%
1536
January1st to 15thNight
18%19%7%10%7%3444414%
2506
16th to endNight
11%17%7%8%7%45%45%5%20%
2688
February1st to 15thNight
10%16%7%10%9%45%44423%
2290
16th to endNight
16%13%6%11%6%2445%6%22%
1922
March1st to 15thNight
20%12%48%6%34345%25%
2146
16th to endNight
14%10%35%5%25%346%38%
2001
April1st to 15thNight
25%10%35%323345%32%
1796
16th to endNight
20%8%35%423445%36%
1707
May1st to 15thNight
21%8%35%5%34435%34%
1440
16th to endNight
20%7%345%25%446%35%
1495
June1st to 15thNight
20%7%47%5%3446%7%28%
1440
16th to endNight
19%6%24436%6%5%6%35%
1440
July1st to 15thNight
14%433326%45%9%42%
1440
16th to endNight
11%5%24435%5%7%8%41%
1514
August1st to 15thNight
13%5%25%5%346%5%8%39%
1455
16th to endNight
11%5%245%2346%6%47%
1881
September1st to 15thNight
19%7%3432445%6%39%
1768
16th to endNight
18%5%24223346%44%
1786
October1st to 15thNight
21%8%27%5%24345%33%
1974
16th to endNight
30%12%26%42443424%
2241
November1st to 15thNight
21%10%36%6%34446%28%
2307
16th to endNight
24%15%5%8%5%3333421%
2520
December1st to 15thNight
23%18%6%9%5%2334417%
2520
16th to endNight
22%19%6%9%6%3433416%
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%35%12%4
1433
16th to endDay
62%5%9%14%7%
1536
February1st to 15thDay
64%48%16%5%
1565
16th to endDay
64%36%13%8%1
1550
March1st to 15thDay
60%5%9%14%8%1
1812
16th to endDay
49%5%9%17%14%3
2223
April1st to 15thDay
56%38%18%10%2
2152
16th to endDay
53%48%17%11%3
2262
May1st to 15thDay
56%5%8%16%11%1
2511
16th to endDay
56%5%10%17%9%1
2622
June1st to 15thDay
58%6%11%14%8%
2520
16th to endDay
55%8%10%17%7%1
2520
July1st to 15thDay
46%7%15%21%8%
2371
16th to endDay
51%8%15%16%8%
2487
August1st to 15thDay
53%9%15%17%4
2489
16th to endDay
43%7%17%21%9%
2309
September1st to 15thDay
49%6%12%20%10%
2112
16th to endDay
44%5%12%28%9%
1843
October1st to 15thDay
56%410%19%8%
1654
16th to endDay
68%5%9%12%4
1631
November1st to 15thDay
56%6%13%14%7%
1548
16th to endDay
64%410%14%5%
1440
December1st to 15thDay
71%5%8%11%3
1440
16th to endDay
71%5%7%8%6%
1536
January1st to 15thNight
71%48%10%3
2506
16th to endNight
62%5%9%13%7%1
2688
February1st to 15thNight
63%5%10%15%5%
2299
16th to endNight
61%410%13%8%
1922
March1st to 15thNight
60%5%9%16%7%1
2146
16th to endNight
47%411%18%16%1
2001
April1st to 15thNight
54%47%20%11%2
1796
16th to endNight
48%411%18%14%2
1707
May1st to 15thNight
51%5%8%17%12%3
1440
16th to endNight
48%6%10%20%11%1
1497
June1st to 15thNight
53%9%10%18%7%
1440
16th to endNight
47%7%12%19%11%
1440
July1st to 15thNight
36%8%18%24%11%
1360
16th to endNight
37%9%18%24%10%
1418
August1st to 15thNight
41%10%17%23%6%
1445
16th to endNight
36%8%18%28%8%
1881
September1st to 15thNight
45%6%13%23%10%
1768
16th to endNight
40%5%14%31%8%
1786
October1st to 15thNight
51%6%11%20%10%
1974
16th to endNight
63%410%15%5%
2241
November1st to 15thNight
56%5%12%16%7%1
2307
16th to endNight
66%49%13%5%
2520
December1st to 15thNight
70%5%10%11%2
2520
16th to endNight
71%48%9%5%
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
30%23%25%18%3
60
16th to endDay
31%18%31%10%6%1
64
February1st to 15thDay
29%29%29%7%3
88
16th to endDay
30%21%26%17%3
209
March1st to 15thDay
26%21%30%17%3
270
16th to endDay
26%16%27%19%7%2
288
April1st to 15thDay
32%18%24%14%7%1
270
16th to endDay
29%17%25%15%8%2
270
May1st to 15thDay
32%15%27%15%6%1
288
16th to endDay
28%15%30%18%6%
331
June1st to 15thDay
33%14%27%17%6%
315
16th to endDay
21%14%34%20%6%1
315
July1st to 15thDay
19%9%37%23%7%2
305
16th to endDay
18%7%32%31%7%2
326
August1st to 15thDay
21%6%26%29%11%4
313
16th to endDay
20%6%29%19%15%8%
332
September1st to 15thDay
24%10%23%20%13%8%
299
16th to endDay
25%12%21%19%12%7%
254
October1st to 15thDay
30%19%16%20%9%2
255
16th to endDay
38%16%19%14%9%
249
November1st to 15thDay
24%16%22%24%9%1
202
16th to endDay
40%20%23%15%1
60
December1st to 15thDay
46%13%25%13%1
60
16th to endDay
43%29%25%1
64
January1st to 15thNight
27%20%29%17%4
720
16th to endNight
20%16%33%21%6%1
768
February1st to 15thNight
18%20%35%19%4
704
16th to endNight
24%18%32%20%4
631
March1st to 15thNight
27%18%29%21%2
720
16th to endNight
21%15%29%24%7%1
768
April1st to 15thNight
31%14%26%23%4
718
16th to endNight
26%16%27%19%9%
627
May1st to 15thNight
24%10%27%26%8%2
360
16th to endNight
22%7%37%22%9%
375
June1st to 15thNight
24%9%27%30%7%
360
16th to endNight
21%422%35%15%
360
July1st to 15thNight
15%5%23%37%16%
340
16th to endNight
11%5%27%36%17%1
376
August1st to 15thNight
17%220%35%23%
374
16th to endNight
15%7%22%32%20%2
735
September1st to 15thNight
22%5%23%31%14%1
707
16th to endNight
20%9%22%27%17%2
657
October1st to 15thNight
24%13%26%23%10%
660
16th to endNight
36%14%20%21%6%
704
November1st to 15thNight
25%15%27%20%9%1
700
16th to endNight
31%20%23%16%6%1
720
December1st to 15thNight
32%20%26%16%4
720
16th to endNight
35%18%27%14%41
768
Page generated at 2017-09-13 07:39:17. Version ac04

Copyright 2017 A. Danko


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