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 2018-03-11.

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%
15361
11%
49177
6%
15329
32%
15329
14%
36751

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%
780
8%
2716
3%
776
19%
776
7%
2190
January16th to endNight
18%
832
9%
2912
4%
832
26%
832
8%
2268
February1st to 15thNight
17%
764
9%
2548
3%
761
25%
761
9%
2043
February16th to endNight
16%
683
11%
2049
4%
683
25%
683
12%
1601
March1st to 15thNight
18%
764
13%
2291
6%
764
26%
764
14%
1746
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%
720
12%
1844
6%
720
42%
720
26%
1309
September16th to endNight
42%
717
18%
1980
11%
717
47%
717
29%
1305
October1st to 15thNight
33%
720
16%
2079
9%
720
39%
720
20%
1497
October16th to endNight
21%
768
10%
2496
5%
768
28%
768
12%
1907
November1st to 15thNight
26%
760
14%
2472
9%
760
34%
760
13%
1838
November16th to endNight
22%
798
12%
2737
6%
798
30%
798
11%
2078
December1st to 15thNight
14%
825
5%
2925
2%
825
19%
825
7%
2383
December16th to endNight
14%
863
9%
3048
3%
863
20%
863
7%
2499

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%
49442
Night
19%10%47%6%34445%29%
49347
TransparencyDay
55%6%11%17%7%
49130
Night
57%6%11%16%8%
49177
SeeingDay
26%12%27%21%10%2
6490
Night
25%10%29%25%7%
15361

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
20%16%5%10%7%3433419%
1552
16th to endDay
10%16%6%9%7%35%5%45%23%
1664
February1st to 15thDay
12%15%7%10%9%44345%21%
1640
16th to endDay
14%15%6%9%6%25%445%23%
1710
March1st to 15thDay
19%13%5%8%433335%27%
1896
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%5%25%42345%7%37%
2115
16th to endDay
17%5%35%423336%44%
1980
October1st to 15thDay
25%7%36%5%22446%31%
1878
16th to endDay
26%13%36%6%3444422%
1728
November1st to 15thDay
22%10%46%6%24445%28%
1716
16th to endDay
24%15%5%6%5%2233325%
1550
December1st to 15thDay
26%16%5%8%5%3323322%
1365
16th to endDay
24%15%6%9%5%3433419%
1524
January1st to 15thNight
20%16%6%9%6%3433421%
2716
16th to endNight
14%14%6%10%6%46%5%45%22%
2912
February1st to 15thNight
10%14%6%12%10%5%5%44420%
2547
16th to endNight
18%13%6%9%6%3433326%
2049
March1st to 15thNight
21%12%35%6%4434330%
2278
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
20%5%35%422347%38%
1844
16th to endNight
18%5%14423346%45%
1980
October1st to 15thNight
20%7%35%5%34446%35%
2079
16th to endNight
28%10%36%5%3334327%
2496
November1st to 15thNight
19%10%38%5%34346%30%
2472
16th to endNight
22%13%5%8%42334427%
2737
December1st to 15thNight
24%14%6%10%6%2433320%
2925
16th to endNight
22%18%5%9%5%3433419%
3048

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%48%11%4
1553
16th to endDay
61%5%10%17%5%
1664
February1st to 15thDay
65%410%12%5%
1643
16th to endDay
62%5%9%14%6%1
1710
March1st to 15thDay
60%49%13%10%
1906
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
46%7%14%22%9%
2115
16th to endDay
42%415%28%8%
1980
October1st to 15thDay
53%5%13%21%5%
1878
16th to endDay
64%5%9%17%2
1728
November1st to 15thDay
58%6%11%16%7%
1716
16th to endDay
63%411%15%4
1550
December1st to 15thDay
69%411%12%3
1365
16th to endDay
70%48%9%6%
1524
January1st to 15thNight
67%5%8%13%4
2716
16th to endNight
63%6%9%14%5%
2912
February1st to 15thNight
66%49%13%5%
2548
16th to endNight
62%49%12%10%
2049
March1st to 15thNight
59%49%15%9%1
2291
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
45%6%14%23%9%
1844
16th to endNight
39%6%15%26%11%
1980
October1st to 15thNight
50%6%10%23%8%
2079
16th to endNight
60%5%11%17%5%
2496
November1st to 15thNight
55%6%12%16%7%
2472
16th to endNight
61%411%16%6%
2737
December1st to 15thNight
69%5%10%11%3
2925
16th to endNight
69%48%9%6%
3048

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
31%20%28%18%1
90
16th to endDay
26%28%30%11%31
96
February1st to 15thDay
27%19%34%13%4
166
16th to endDay
26%14%34%21%4
291
March1st to 15thDay
29%16%29%20%3
312
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
22%8%21%26%14%6%
315
16th to endDay
16%12%25%21%18%5%
314
October1st to 15thDay
31%8%24%21%11%3
306
16th to endDay
36%13%21%21%6%
288
November1st to 15thDay
28%16%24%18%10%1
280
16th to endDay
34%14%24%19%6%
161
December1st to 15thDay
36%15%31%12%31
90
16th to endDay
38%18%29%10%21
96
January1st to 15thNight
27%15%33%19%3
780
16th to endNight
21%15%32%24%5%
832
February1st to 15thNight
17%13%39%25%4
764
16th to endNight
27%12%34%20%4
683
March1st to 15thNight
29%11%36%19%3
764
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
24%424%32%11%1
720
16th to endNight
20%6%27%28%16%
717
October1st to 15thNight
24%8%28%28%8%1
720
16th to endNight
34%10%28%19%5%
768
November1st to 15thNight
25%16%25%23%9%
760
16th to endNight
28%14%29%16%9%1
798
December1st to 15thNight
31%14%30%18%4
825
16th to endNight
31%15%30%17%3
863
Page generated at 2018-03-12 13:28:08. Version ac04

Copyright 2018 A. Danko


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