Amik Reservoir
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Amik Reservoir clear sky chart from 2005-11-05 to 2017-10-06.

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
38%
15567
16%
46816
11%
15527
43%
15527
21%
32495

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%
719
11%
2327
4%
716
21%
716
9%
1856
January16th to endNight
16%
768
12%
2496
5%
768
23%
768
11%
1962
February1st to 15thNight
17%
701
10%
2258
5%
701
22%
701
12%
1734
February16th to endNight
18%
631
12%
1893
5%
631
25%
631
12%
1458
March1st to 15thNight
26%
720
13%
2049
8%
720
31%
720
16%
1539
March16th to endNight
30%
768
16%
2112
10%
768
35%
768
21%
1515
April1st to 15thNight
28%
637
13%
1853
7%
637
34%
637
20%
1310
April16th to endNight
33%
540
19%
1620
7%
540
42%
540
24%
1075
May1st to 15thNight
38%
540
14%
1620
9%
540
43%
540
19%
1153
May16th to endNight
51%
562
17%
1684
13%
561
55%
561
28%
1064
June1st to 15thNight
56%
540
14%
1608
11%
540
60%
540
31%
967
June16th to endNight
60%
540
16%
1440
12%
540
63%
540
33%
920
July1st to 15thNight
62%
510
16%
1407
14%
510
63%
510
33%
891
July16th to endNight
69%
564
19%
1595
16%
531
72%
531
37%
913
August1st to 15thNight
71%
539
21%
1609
18%
536
72%
536
35%
960
August16th to endNight
70%
573
24%
1729
21%
573
73%
573
38%
984
September1st to 15thNight
61%
702
26%
1962
19%
702
65%
702
36%
1172
September16th to endNight
58%
717
28%
1980
22%
717
62%
717
34%
1205
October1st to 15thNight
48%
684
23%
1972
20%
684
53%
684
30%
1238
October16th to endNight
27%
704
18%
2150
12%
704
36%
704
19%
1512
November1st to 15thNight
38%
700
22%
2276
16%
700
46%
700
24%
1429
November16th to endNight
25%
720
14%
2340
10%
720
32%
720
15%
1699
December1st to 15thNight
19%
720
10%
2340
5%
720
24%
720
10%
1867
December16th to endNight
16%
768
8%
2496
4%
768
21%
768
8%
2072

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
15%9%47%5%3445%7%31%
48368
Night
15%9%46%5%3445%6%34%
47003
Cloud CoverDay
16%9%46%5%3445%7%31%
48378
Night
15%9%46%5%3445%6%35%
47007
TransparencyDay
52%411%19%11%1
48073
Night
50%310%20%12%1
46816
SeeingDay
20%6%23%22%17%8%
5722
Night
20%7%26%28%14%2
15572

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%15%7%11%7%3342318%
1611
16th to endDay
16%16%9%13%8%4443414%
1728
February1st to 15thDay
16%16%6%10%6%35%345%20%
1602
16th to endDay
15%13%7%9%6%35%346%22%
1580
March1st to 15thDay
20%14%7%9%6%33346%23%
1900
16th to endDay
19%12%5%6%6%34446%27%
2112
April1st to 15thDay
19%11%45%5%2445%6%30%
2104
16th to endDay
18%8%26%5%24446%36%
2340
May1st to 15thDay
20%8%37%5%24447%30%
2331
16th to endDay
11%425%7%45%5%6%9%36%
2431
June1st to 15thDay
13%5%25%6%45%46%8%37%
2347
16th to endDay
12%5%245%45%7%6%9%35%
2520
July1st to 15thDay
13%5%26%5%35%5%6%9%37%
2466
16th to endDay
10%414436%6%6%11%38%
2465
August1st to 15thDay
8%415%5%46%6%7%9%38%
2340
16th to endDay
9%425%6%45%5%7%9%38%
2471
September1st to 15thDay
14%5%246%25%45%7%42%
1986
16th to endDay
16%7%246%33346%42%
1980
October1st to 15thDay
16%8%25%5%2345%7%38%
1785
16th to endDay
21%11%25%424347%31%
1719
November1st to 15thDay
12%9%45%42345%6%39%
1582
16th to endDay
19%15%5%7%424326%26%
1620
December1st to 15thDay
20%17%9%10%6%24325%16%
1620
16th to endDay
21%17%9%11%5%33335%14%
1728
January1st to 15thNight
21%16%7%8%6%2433421%
2327
16th to endNight
16%17%6%8%7%34445%21%
2496
February1st to 15thNight
18%13%6%9%6%3443425%
2256
16th to endNight
16%14%6%10%7%34345%24%
1893
March1st to 15thNight
18%11%47%6%24435%29%
2037
16th to endNight
15%9%47%6%25%446%33%
2112
April1st to 15thNight
17%9%46%5%2445%6%33%
1853
16th to endNight
13%8%35%5%35%35%6%39%
1620
May1st to 15thNight
19%7%36%7%3445%6%31%
1620
16th to endNight
12%5%2443447%8%40%
1682
June1st to 15thNight
7%4245%35%6%6%7%46%
1608
16th to endNight
10%4145%26%5%7%10%42%
1440
July1st to 15thNight
8%4245%446%6%8%44%
1491
16th to endNight
5%4234345%6%9%49%
1703
August1st to 15thNight
6%3145%35%6%7%9%45%
1620
16th to endNight
7%42442445%8%51%
1729
September1st to 15thNight
11%425%31435%7%50%
1962
16th to endNight
13%5%2432335%6%49%
1980
October1st to 15thNight
13%5%245%24346%46%
1972
16th to endNight
21%8%26%5%34335%35%
2150
November1st to 15thNight
14%8%25%6%2335%7%41%
2276
16th to endNight
20%11%47%5%23346%28%
2340
December1st to 15thNight
20%17%7%8%5%3333420%
2340
16th to endNight
21%17%7%9%6%34435%16%
2496

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
22%14%7%12%6%3333318%
1611
16th to endDay
16%17%9%13%8%4343413%
1728
February1st to 15thDay
16%16%6%10%7%34345%20%
1602
16th to endDay
15%13%7%9%6%35%436%23%
1580
March1st to 15thDay
21%13%6%8%6%33336%22%
1911
16th to endDay
19%12%5%6%5%34445%27%
2111
April1st to 15thDay
19%11%46%5%24446%30%
2104
16th to endDay
18%8%26%5%24345%36%
2340
May1st to 15thDay
20%8%37%5%24446%30%
2331
16th to endDay
12%5%26%6%36%5%6%8%36%
2431
June1st to 15thDay
14%5%25%6%35%45%9%37%
2347
16th to endDay
12%5%25%5%36%6%6%9%35%
2520
July1st to 15thDay
13%5%25%5%345%5%9%38%
2466
16th to endDay
10%424435%6%7%12%37%
2465
August1st to 15thDay
9%425%6%36%6%7%9%38%
2340
16th to endDay
10%425%6%45%6%6%9%38%
2471
September1st to 15thDay
14%6%15%434447%41%
1986
16th to endDay
16%6%245%23346%41%
1980
October1st to 15thDay
17%8%24424347%38%
1785
16th to endDay
21%10%35%424347%31%
1719
November1st to 15thDay
13%8%45%4235%5%6%39%
1582
16th to endDay
19%16%5%7%424326%26%
1620
December1st to 15thDay
20%17%8%10%6%24335%16%
1620
16th to endDay
21%17%10%10%5%23335%14%
1728
January1st to 15thNight
21%16%7%9%6%3333421%
2327
16th to endNight
16%18%6%8%8%3344421%
2496
February1st to 15thNight
18%13%6%9%6%34435%25%
2249
16th to endNight
16%13%6%10%6%34435%24%
1893
March1st to 15thNight
18%11%5%8%6%34446%28%
2049
16th to endNight
15%9%47%6%25%446%33%
2112
April1st to 15thNight
16%9%46%5%3445%6%33%
1853
16th to endNight
13%7%45%5%35%35%5%39%
1620
May1st to 15thNight
19%7%26%6%4345%6%31%
1619
16th to endNight
12%5%245%245%6%9%40%
1682
June1st to 15thNight
7%4245%346%5%8%46%
1608
16th to endNight
10%424425%6%7%10%41%
1440
July1st to 15thNight
9%4245%4446%8%44%
1491
16th to endNight
6%3334345%7%9%48%
1703
August1st to 15thNight
6%3145%35%6%7%9%45%
1620
16th to endNight
7%41442445%8%51%
1729
September1st to 15thNight
12%42432335%7%50%
1962
16th to endNight
13%6%2432335%6%49%
1980
October1st to 15thNight
13%5%245%24445%46%
1972
16th to endNight
21%8%35%5%34345%35%
2150
November1st to 15thNight
14%8%35%5%2335%6%41%
2276
16th to endNight
20%11%46%5%23345%28%
2340
December1st to 15thNight
20%17%7%9%5%24335%20%
2340
16th to endNight
21%17%8%9%6%34335%16%
2496

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
71%27%11%5%
1612
16th to endDay
73%49%9%2
1728
February1st to 15thDay
66%37%14%7%
1604
16th to endDay
62%311%16%5%
1580
March1st to 15thDay
64%39%16%5%
1911
16th to endDay
58%310%20%5%
2112
April1st to 15thDay
55%313%16%10%
2104
16th to endDay
49%310%20%12%3
2340
May1st to 15thDay
53%5%12%18%8%1
2331
16th to endDay
43%6%13%22%11%1
2435
June1st to 15thDay
43%411%25%13%
2347
16th to endDay
42%7%14%19%15%1
2520
July1st to 15thDay
44%5%10%21%17%1
2321
16th to endDay
36%7%14%26%12%1
2310
August1st to 15thDay
38%6%13%24%15%1
2327
16th to endDay
39%6%12%22%14%4
2471
September1st to 15thDay
42%49%23%17%2
1986
16th to endDay
44%38%19%22%1
1980
October1st to 15thDay
45%49%22%17%1
1785
16th to endDay
53%312%20%9%1
1719
November1st to 15thDay
45%49%22%14%4
1582
16th to endDay
61%38%17%8%
1620
December1st to 15thDay
72%28%11%4
1620
16th to endDay
73%38%10%3
1728
January1st to 15thNight
68%27%14%6%
2327
16th to endNight
65%29%15%5%
2496
February1st to 15thNight
62%39%15%7%
2258
16th to endNight
63%37%19%6%
1893
March1st to 15thNight
57%310%18%7%1
2049
16th to endNight
51%310%22%9%1
2112
April1st to 15thNight
51%311%16%15%1
1853
16th to endNight
45%310%19%17%3
1620
May1st to 15thNight
52%410%19%11%1
1620
16th to endNight
39%412%24%15%3
1684
June1st to 15thNight
35%5%13%26%17%1
1608
16th to endNight
35%6%15%22%15%3
1440
July1st to 15thNight
36%5%12%22%19%3
1407
16th to endNight
29%5%14%30%15%3
1595
August1st to 15thNight
33%5%14%26%19%1
1609
16th to endNight
30%414%25%20%3
1729
September1st to 15thNight
33%311%25%20%5%
1962
16th to endNight
36%37%25%25%2
1980
October1st to 15thNight
39%39%24%20%2
1972
16th to endNight
52%29%24%10%1
2150
November1st to 15thNight
43%310%22%15%4
2276
16th to endNight
57%210%18%9%
2340
December1st to 15thNight
68%29%13%5%
2340
16th to endNight
71%39%12%2
2496

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%15%33%11%8%1
90
16th to endDay
31%17%34%13%3
96
February1st to 15thDay
25%18%45%10%
90
16th to endDay
20%13%44%17%3
81
March1st to 15thDay
27%13%31%21%4
201
16th to endDay
23%12%33%19%8%1
288
April1st to 15thDay
26%9%29%21%10%2
270
16th to endDay
24%7%31%18%11%7%
270
May1st to 15thDay
29%426%22%10%5%
288
16th to endDay
17%325%27%16%9%
331
June1st to 15thDay
18%218%29%25%5%
322
16th to endDay
18%6%24%27%17%5%
495
July1st to 15thDay
18%219%29%23%8%
425
16th to endDay
12%112%25%29%18%
326
August1st to 15thDay
15%110%25%27%19%
313
16th to endDay
11%312%23%31%18%
332
September1st to 15thDay
16%214%21%26%18%
315
16th to endDay
15%411%20%28%20%
314
October1st to 15thDay
16%5%24%24%21%8%
278
16th to endDay
25%8%33%24%7%
231
November1st to 15thDay
12%11%22%22%27%4
90
16th to endDay
27%10%42%13%5%1
90
December1st to 15thDay
26%23%35%8%23
90
16th to endDay
28%23%37%9%1
96
January1st to 15thNight
28%13%38%16%2
720
16th to endNight
24%14%36%20%3
768
February1st to 15thNight
23%11%39%20%4
704
16th to endNight
24%11%37%22%4
631
March1st to 15thNight
24%10%30%26%6%
720
16th to endNight
20%8%35%25%9%
768
April1st to 15thNight
22%10%34%25%6%
637
16th to endNight
18%6%36%24%11%2
540
May1st to 15thNight
23%426%32%11%1
540
16th to endNight
15%321%33%21%4
563
June1st to 15thNight
8%223%42%20%2
540
16th to endNight
12%217%42%22%2
540
July1st to 15thNight
11%16%43%26%2
510
16th to endNight
7%113%38%35%4
564
August1st to 15thNight
9%8%45%29%6%
539
16th to endNight
8%19%36%35%7%
573
September1st to 15thNight
15%213%31%30%6%
702
16th to endNight
17%214%29%28%7%
717
October1st to 15thNight
16%323%33%18%3
684
16th to endNight
26%7%32%23%9%
704
November1st to 15thNight
19%7%29%29%12%1
700
16th to endNight
26%12%28%23%8%
720
December1st to 15thNight
31%11%30%21%3
720
16th to endNight
29%12%33%20%4
768
Page generated at 2017-10-07 14:07:54. Version ac04

Copyright 2017 A. Danko


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