Saint-Agapit
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Saint-Agapit 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
26%
14609
11%
46809
6%
14577
32%
14577
14%
35016

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
13%
720
8%
2506
3%
716
19%
716
7%
2033
January16th to endNight
19%
768
9%
2688
4%
768
26%
768
8%
2104
February1st to 15thNight
18%
704
9%
2348
4%
701
25%
701
9%
1874
February16th to endNight
17%
631
10%
1893
4%
631
25%
631
12%
1490
March1st to 15thNight
19%
720
14%
2160
7%
720
27%
720
14%
1626
March16th to endNight
30%
768
16%
2021
7%
768
37%
768
19%
1489
April1st to 15thNight
23%
718
13%
1796
5%
718
28%
718
18%
1388
April16th to endNight
26%
546
15%
1626
6%
546
32%
546
19%
1144
May1st to 15thNight
28%
456
13%
1536
11%
456
34%
456
15%
1109
May16th to endNight
28%
375
10%
1497
9%
374
37%
374
13%
1064
June1st to 15thNight
33%
360
7%
1272
5%
360
37%
360
13%
938
June16th to endNight
39%
360
8%
1269
8%
360
42%
360
17%
901
July1st to 15thNight
40%
340
8%
1360
11%
340
44%
340
18%
897
July16th to endNight
46%
376
10%
1418
13%
354
48%
354
17%
930
August1st to 15thNight
48%
415
11%
1486
11%
413
51%
413
17%
1015
August16th to endNight
45%
653
15%
1799
9%
653
47%
653
25%
1212
September1st to 15thNight
40%
707
11%
1808
5%
707
42%
707
25%
1295
September16th to endNight
40%
657
18%
1815
11%
657
45%
657
28%
1211
October1st to 15thNight
31%
660
16%
1906
9%
660
38%
660
19%
1392
October16th to endNight
20%
704
9%
2288
4%
704
27%
704
11%
1762
November1st to 15thNight
26%
700
15%
2277
9%
700
34%
700
13%
1695
November16th to endNight
23%
732
12%
2526
7%
732
30%
732
11%
1922
December1st to 15thNight
14%
750
5%
2700
2%
750
18%
750
6%
2202
December16th to endNight
14%
789
8%
2814
3%
789
20%
789
6%
2323

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%9%46%5%34446%29%
47843
Night
20%10%47%6%34445%29%
46979
TransparencyDay
55%6%11%17%7%
47531
Night
57%6%11%16%8%
46809
SeeingDay
26%11%27%22%10%2
5971
Night
25%10%29%25%7%
14609

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
19%16%6%10%7%3433419%
1432
16th to endDay
10%17%6%9%7%345%45%23%
1536
February1st to 15thDay
11%14%7%10%9%44345%22%
1510
16th to endDay
13%15%7%9%6%36%445%22%
1580
March1st to 15thDay
19%12%5%8%434335%28%
1790
16th to endDay
17%10%46%5%3445%5%33%
2199
April1st to 15thDay
24%9%46%423225%32%
2152
16th to endDay
22%9%35%42433435%
2332
May1st to 15thDay
24%8%35%425%345%30%
2424
16th to endDay
22%7%47%5%25%45%5%28%
2618
June1st to 15thDay
23%6%35%5%45%5%5%6%27%
2685
16th to endDay
22%6%36%5%35%5%5%7%27%
2687
July1st to 15thDay
15%6%36%5%35%5%6%8%32%
2520
16th to endDay
16%7%36%5%36%5%7%8%28%
2654
August1st to 15thDay
19%7%26%6%46%5%6%9%26%
2451
16th to endDay
15%5%25%5%3345%8%40%
2402
September1st to 15thDay
21%6%25%5%2345%7%35%
2071
16th to endDay
18%6%35%423336%42%
1815
October1st to 15thDay
25%6%36%5%22446%30%
1722
16th to endDay
27%14%36%6%3444421%
1584
November1st to 15thDay
22%10%46%6%23345%28%
1581
16th to endDay
24%15%5%6%5%2233326%
1431
December1st to 15thDay
27%15%5%8%5%3323322%
1260
16th to endDay
25%16%6%9%5%3433420%
1407
January1st to 15thNight
20%16%6%9%7%3433420%
2506
16th to endNight
13%15%6%10%6%46%5%4422%
2688
February1st to 15thNight
9%13%6%12%11%5%5%445%20%
2347
16th to endNight
17%13%7%9%6%2433325%
1893
March1st to 15thNight
21%11%35%6%3434331%
2147
16th to endNight
16%11%45%5%34445%34%
2021
April1st to 15thNight
24%10%46%5%24446%27%
1796
16th to endNight
23%8%25%6%12346%36%
1626
May1st to 15thNight
23%9%35%6%2433433%
1536
16th to endNight
25%7%36%424345%31%
1495
June1st to 15thNight
23%9%35%6%245%45%28%
1272
16th to endNight
19%6%26%6%345%5%7%31%
1269
July1st to 15thNight
17%5%36%5%2446%7%35%
1440
16th to endNight
14%5%36%5%346%6%7%36%
1514
August1st to 15thNight
15%6%26%5%35%5%6%8%33%
1496
16th to endNight
14%5%245%435%48%40%
1799
September1st to 15thNight
21%5%35%422347%37%
1808
16th to endNight
20%5%14323346%44%
1815
October1st to 15thNight
21%7%35%5%34446%33%
1906
16th to endNight
28%11%36%5%3334327%
2288
November1st to 15thNight
19%10%38%5%34346%29%
2277
16th to endNight
22%14%5%8%42334426%
2526
December1st to 15thNight
24%14%6%10%6%2433320%
2700
16th to endNight
23%18%5%9%5%3333319%
2814

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
69%5%8%11%5%
1433
16th to endDay
61%5%9%16%5%
1536
February1st to 15thDay
65%410%12%5%
1513
16th to endDay
63%5%8%14%6%1
1580
March1st to 15thDay
59%49%14%10%1
1800
16th to endDay
52%5%10%17%11%2
2199
April1st to 15thDay
56%48%17%9%3
2152
16th to endDay
52%49%17%12%2
2332
May1st to 15thDay
55%6%9%17%11%1
2424
16th to endDay
57%7%10%15%9%
2622
June1st to 15thDay
55%8%11%15%7%1
2685
16th to endDay
55%8%10%17%8%
2687
July1st to 15thDay
46%8%16%20%7%
2371
16th to endDay
52%9%14%17%5%
2487
August1st to 15thDay
52%10%17%16%3
2437
16th to endDay
42%7%15%26%7%
2402
September1st to 15thDay
47%7%14%21%9%
2071
16th to endDay
44%414%28%7%
1815
October1st to 15thDay
54%5%13%20%5%
1722
16th to endDay
66%5%8%16%2
1584
November1st to 15thDay
57%6%11%16%7%
1581
16th to endDay
62%411%16%4
1431
December1st to 15thDay
69%410%12%2
1260
16th to endDay
70%48%9%5%
1407
January1st to 15thNight
68%5%9%12%3
2506
16th to endNight
63%6%9%14%5%
2688
February1st to 15thNight
65%49%13%5%
2348
16th to endNight
63%49%11%9%
1893
March1st to 15thNight
58%49%16%9%1
2160
16th to endNight
51%6%9%16%13%2
2021
April1st to 15thNight
57%48%16%10%2
1796
16th to endNight
50%49%18%13%3
1626
May1st to 15thNight
54%5%9%15%13%1
1536
16th to endNight
55%5%10%16%11%
1497
June1st to 15thNight
56%7%11%16%7%1
1272
16th to endNight
50%7%11%18%10%
1269
July1st to 15thNight
44%9%16%20%8%
1360
16th to endNight
44%9%15%19%10%
1418
August1st to 15thNight
45%10%16%22%4
1486
16th to endNight
41%8%16%25%7%
1799
September1st to 15thNight
46%6%14%22%9%
1808
16th to endNight
41%6%13%27%10%
1815
October1st to 15thNight
51%6%10%22%8%
1906
16th to endNight
61%5%11%16%5%
2288
November1st to 15thNight
55%6%12%15%8%
2277
16th to endNight
61%411%16%5%
2526
December1st to 15thNight
69%5%10%11%2
2700
16th to endNight
70%5%8%9%6%
2814

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
28%20%33%16%1
60
16th to endDay
34%18%28%12%41
64
February1st to 15thDay
26%16%34%17%5%
126
16th to endDay
25%12%33%23%5%
239
March1st to 15thDay
26%18%28%21%31
270
16th to endDay
22%13%28%20%12%2
288
April1st to 15thDay
32%15%24%20%6%
270
16th to endDay
28%14%29%16%8%2
270
May1st to 15thDay
35%7%29%16%8%1
288
16th to endDay
22%17%31%18%9%
331
June1st to 15thDay
29%7%27%25%9%
480
16th to endDay
24%9%28%25%12%
482
July1st to 15thDay
19%11%28%26%11%2
305
16th to endDay
20%427%31%14%2
326
August1st to 15thDay
20%7%24%26%15%4
313
16th to endDay
20%9%25%20%15%7%
332
September1st to 15thDay
23%8%20%26%13%7%
299
16th to endDay
19%13%25%20%15%4
254
October1st to 15thDay
30%8%25%20%10%4
249
16th to endDay
37%13%20%23%6%
240
November1st to 15thDay
28%16%24%20%8%1
235
16th to endDay
33%13%24%19%7%
126
December1st to 15thDay
40%13%31%11%3
60
16th to endDay
48%20%25%41
64
January1st to 15thNight
27%16%33%19%3
720
16th to endNight
20%15%33%24%5%
768
February1st to 15thNight
17%13%38%25%4
704
16th to endNight
27%12%34%21%4
631
March1st to 15thNight
28%11%37%19%4
720
16th to endNight
21%11%31%26%7%
768
April1st to 15thNight
30%11%28%23%5%
718
16th to endNight
27%11%28%23%7%
546
May1st to 15thNight
26%7%30%27%6%
456
16th to endNight
25%9%29%30%4
375
June1st to 15thNight
27%5%26%32%7%
360
16th to endNight
23%426%35%9%
360
July1st to 15thNight
17%430%32%14%
340
16th to endNight
15%325%46%9%
376
August1st to 15thNight
19%321%35%18%1
415
16th to endNight
17%5%26%34%14%1
653
September1st to 15thNight
25%424%31%11%1
707
16th to endNight
22%7%28%28%13%
657
October1st to 15thNight
26%9%27%27%8%1
660
16th to endNight
34%10%29%18%5%
704
November1st to 15thNight
25%16%25%24%8%
700
16th to endNight
29%14%27%17%9%1
732
December1st to 15thNight
31%14%30%19%4
750
16th to endNight
33%15%29%16%31
789
Page generated at 2017-09-13 07:39:07. Version ac04

Copyright 2017 A. Danko


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