Ste-Félicité
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Ste-Félicité clear sky chart from 2005-11-05 to 2019-06-24.

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%
16937
9%
53961
5%
16906
31%
16906
11%
42152

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
12%
900
5%
3135
1%
896
16%
896
4%
2774
January16th to endNight
20%
905
9%
3167
4%
905
26%
905
6%
2625
February1st to 15thNight
21%
823
8%
2718
3%
821
27%
821
8%
2185
February16th to endNight
20%
735
7%
2316
3%
735
26%
735
9%
1866
March1st to 15thNight
24%
840
15%
2419
8%
840
31%
840
13%
1885
March16th to endNight
27%
896
16%
2464
7%
896
35%
896
17%
1841
April1st to 15thNight
24%
707
13%
2001
6%
707
29%
707
12%
1573
April16th to endNight
30%
623
15%
1869
9%
623
35%
623
17%
1342
May1st to 15thNight
36%
630
9%
1796
7%
630
39%
630
18%
1355
May16th to endNight
28%
439
10%
1534
5%
438
35%
438
13%
1131
June1st to 15thNight
41%
420
6%
1470
5%
420
43%
420
17%
1032
June16th to endNight
40%
406
5%
1422
4%
406
41%
406
15%
1011
July1st to 15thNight
40%
370
6%
1295
5%
370
42%
370
18%
892
July16th to endNight
48%
408
9%
1406
9%
386
51%
386
18%
946
August1st to 15thNight
51%
522
8%
1663
8%
520
52%
520
19%
1163
August16th to endNight
47%
621
13%
1863
9%
621
50%
621
22%
1278
September1st to 15thNight
41%
677
13%
1987
10%
677
43%
677
21%
1389
September16th to endNight
32%
777
15%
2145
10%
777
37%
777
23%
1460
October1st to 15thNight
31%
780
14%
2306
7%
780
37%
780
18%
1640
October16th to endNight
23%
832
8%
2655
4%
832
27%
832
10%
2094
November1st to 15thNight
18%
866
9%
2827
5%
866
23%
866
9%
2236
November16th to endNight
17%
900
5%
2993
3%
900
20%
900
5%
2554
December1st to 15thNight
9%
900
3%
3150
1%
900
12%
900
2%
2886
December16th to endNight
13%
960
3%
3360
1%
960
16%
960
3%
2994

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
19%10%47%6%35%446%28%
54885
Night
19%12%5%8%7%35%445%23%
54114
TransparencyDay
57%413%17%6%
54556
Night
63%410%15%6%
53961
SeeingDay
26%9%26%24%11%2
8947
Night
25%12%24%25%10%1
16938

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
17%17%7%13%10%6%5%35%47%
1463
16th to endDay
11%13%6%11%8%6%9%7%4315%
1759
February1st to 15thDay
8%13%411%10%7%9%6%5%5%16%
1803
16th to endDay
13%14%6%10%8%45%5%5%5%21%
1729
March1st to 15thDay
15%14%5%7%5%46%6%46%25%
2190
16th to endDay
14%14%5%7%6%34345%29%
2464
April1st to 15thDay
19%12%5%6%5%3435%5%28%
2605
16th to endDay
20%9%345%34346%33%
2696
May1st to 15thDay
22%9%35%423346%32%
2827
16th to endDay
25%7%245%2435%6%30%
3285
June1st to 15thDay
21%7%25%5%245%5%6%32%
3150
16th to endDay
22%6%34435%5%5%8%29%
3045
July1st to 15thDay
15%7%25%5%345%6%8%34%
2925
16th to endDay
15%6%25%5%35%5%5%7%36%
3023
August1st to 15thDay
15%6%36%5%345%5%8%34%
2527
16th to endDay
16%4245%345%5%8%37%
2691
September1st to 15thDay
22%5%25%323336%40%
2301
16th to endDay
21%6%25%424435%39%
2145
October1st to 15thDay
22%8%345%24446%31%
1983
16th to endDay
28%14%45%423345%23%
1921
November1st to 15thDay
25%13%6%8%6%2443420%
1691
16th to endDay
22%16%6%12%8%2434314%
1624
December1st to 15thDay
18%15%7%13%16%5%5%4337%
1470
16th to endDay
17%18%8%13%11%6%6%3337%
1568
January1st to 15thNight
17%17%7%11%12%6%44439%
3135
16th to endNight
10%15%6%10%9%6%10%6%4414%
3167
February1st to 15thNight
8%13%6%11%9%7%8%6%45%18%
2717
16th to endNight
15%18%6%9%8%45%335%19%
2316
March1st to 15thNight
17%13%6%8%7%35%43325%
2407
16th to endNight
15%14%5%6%7%33335%31%
2464
April1st to 15thNight
22%13%47%7%34345%24%
2001
16th to endNight
26%8%36%423245%32%
1869
May1st to 15thNight
24%8%37%425%435%28%
1796
16th to endNight
24%7%36%6%245%6%5%25%
1532
June1st to 15thNight
22%7%35%6%245%5%6%30%
1470
16th to endNight
22%8%36%5%3445%5%30%
1422
July1st to 15thNight
17%7%37%6%35%46%8%30%
1365
16th to endNight
15%5%35%5%35%6%6%9%32%
1494
August1st to 15thNight
15%6%25%6%45%6%6%8%31%
1673
16th to endNight
17%6%25%5%35%6%5%8%33%
1863
September1st to 15thNight
19%6%36%5%34446%36%
1987
16th to endNight
24%424422345%41%
2145
October1st to 15thNight
22%8%25%424446%33%
2306
16th to endNight
29%13%45%42433423%
2655
November1st to 15thNight
26%14%5%6%42444421%
2827
16th to endNight
20%18%7%12%6%3433414%
2993
December1st to 15thNight
19%18%9%14%13%443227%
3150
16th to endNight
18%19%7%12%11%5%6%3339%
3360

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
80%38%6%1
1464
16th to endDay
69%5%9%11%4
1759
February1st to 15thDay
65%5%13%12%2
1806
16th to endDay
63%49%17%4
1729
March1st to 15thDay
60%410%16%6%
2201
16th to endDay
57%210%18%9%1
2464
April1st to 15thDay
58%210%18%8%1
2605
16th to endDay
51%310%20%12%1
2696
May1st to 15thDay
52%311%21%9%1
2827
16th to endDay
54%411%19%9%
3289
June1st to 15thDay
51%6%10%19%10%1
3150
16th to endDay
53%6%13%18%8%
3045
July1st to 15thDay
44%6%18%22%7%
2766
16th to endDay
46%5%18%22%7%
2848
August1st to 15thDay
46%6%22%21%3
2513
16th to endDay
43%6%24%19%6%
2691
September1st to 15thDay
46%417%24%7%
2301
16th to endDay
48%415%24%7%
2145
October1st to 15thDay
53%5%15%16%8%
1983
16th to endDay
64%313%14%3
1921
November1st to 15thDay
68%312%11%3
1691
16th to endDay
75%311%8%1
1624
December1st to 15thDay
82%47%4
1470
16th to endDay
83%37%41
1568
January1st to 15thNight
79%37%6%2
3135
16th to endNight
71%46%13%3
3167
February1st to 15thNight
67%49%14%3
2718
16th to endNight
68%37%14%5%
2316
March1st to 15thNight
63%26%18%7%
2419
16th to endNight
57%28%19%10%1
2464
April1st to 15thNight
62%36%12%12%1
2001
16th to endNight
54%36%21%13%1
1869
May1st to 15thNight
57%29%19%10%
1796
16th to endNight
58%5%7%18%9%1
1534
June1st to 15thNight
52%410%20%10%1
1470
16th to endNight
53%5%10%18%11%
1422
July1st to 15thNight
50%5%16%21%6%
1295
16th to endNight
46%7%15%20%9%
1406
August1st to 15thNight
47%8%18%20%4
1663
16th to endNight
46%6%19%22%5%
1863
September1st to 15thNight
48%5%12%23%9%
1987
16th to endNight
46%314%23%11%
2145
October1st to 15thNight
52%413%20%8%
2306
16th to endNight
65%312%14%4
2655
November1st to 15thNight
66%312%12%4
2827
16th to endNight
74%5%9%8%2
2993
December1st to 15thNight
85%25%5%
3150
16th to endNight
81%38%5%1
3360

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%16%33%21%3
120
16th to endDay
21%22%32%16%6%
128
February1st to 15thDay
17%15%31%28%5%1
284
16th to endDay
24%15%32%19%6%1
311
March1st to 15thDay
22%14%27%24%9%1
390
16th to endDay
23%12%29%19%11%3
416
April1st to 15thDay
25%15%28%18%8%2
390
16th to endDay
30%8%29%18%8%3
379
May1st to 15thDay
29%7%31%21%8%3
500
16th to endDay
32%7%24%23%9%2
679
June1st to 15thDay
27%6%22%26%14%2
645
16th to endDay
27%5%24%27%13%1
610
July1st to 15thDay
22%426%27%14%4
550
16th to endDay
21%419%33%16%3
534
August1st to 15thDay
18%323%31%18%5%
358
16th to endDay
20%424%29%15%5%
396
September1st to 15thDay
27%424%25%14%3
375
16th to endDay
26%9%30%22%9%2
374
October1st to 15thDay
27%14%27%21%8%1
325
16th to endDay
39%13%17%15%9%2
336
November1st to 15thDay
36%17%23%14%7%1
325
16th to endDay
30%14%26%20%7%
274
December1st to 15thDay
26%6%29%25%10%1
120
16th to endDay
26%18%23%25%6%
128
January1st to 15thNight
25%18%30%18%5%
900
16th to endNight
16%20%29%24%6%
905
February1st to 15thNight
15%16%32%26%8%
824
16th to endNight
25%13%28%22%8%2
735
March1st to 15thNight
24%12%27%25%9%
840
16th to endNight
23%13%25%23%11%1
896
April1st to 15thNight
29%14%23%20%9%1
707
16th to endNight
29%10%20%25%11%2
623
May1st to 15thNight
26%5%23%30%12%1
630
16th to endNight
28%6%26%25%11%1
439
June1st to 15thNight
26%416%34%17%
420
16th to endNight
25%419%34%14%1
406
July1st to 15thNight
21%6%20%33%14%3
370
16th to endNight
15%5%19%35%22%2
408
August1st to 15thNight
19%314%34%25%3
522
16th to endNight
18%420%36%18%2
621
September1st to 15thNight
24%6%21%29%16%1
677
16th to endNight
26%8%26%27%9%1
777
October1st to 15thNight
27%11%23%25%10%1
780
16th to endNight
38%13%19%20%8%
832
November1st to 15thNight
34%15%24%19%5%1
866
16th to endNight
30%15%24%21%6%1
900
December1st to 15thNight
27%22%25%19%4
900
16th to endNight
27%18%24%20%7%1
960
Page generated at 2019-06-24 20:41:32. Version ac04

Copyright 2019 A. Danko


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