Edja Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Edja Lake clear sky chart from 2005-11-05 to 2017-10-16.

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
30%
14710
12%
47189
8%
14678
35%
14678
15%
34440

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
16%
720
6%
2506
3%
716
20%
716
6%
2085
January16th to endNight
22%
768
10%
2652
5%
768
29%
768
11%
2033
February1st to 15thNight
18%
704
9%
2287
4%
701
24%
701
9%
1810
February16th to endNight
21%
631
11%
1964
5%
631
31%
631
11%
1516
March1st to 15thNight
22%
720
12%
2097
8%
720
27%
720
13%
1631
March16th to endNight
31%
768
20%
2037
10%
768
39%
768
21%
1433
April1st to 15thNight
27%
718
15%
1796
7%
718
31%
718
20%
1322
April16th to endNight
30%
614
17%
1694
9%
614
35%
614
20%
1196
May1st to 15thNight
32%
360
17%
1440
17%
360
40%
360
16%
965
May16th to endNight
33%
375
12%
1497
10%
374
44%
374
16%
998
June1st to 15thNight
36%
360
7%
1440
7%
360
41%
360
15%
967
June16th to endNight
43%
360
8%
1440
11%
360
47%
360
18%
937
July1st to 15thNight
50%
340
11%
1360
16%
340
55%
340
24%
791
July16th to endNight
57%
376
12%
1418
16%
354
59%
354
24%
837
August1st to 15thNight
51%
430
13%
1501
12%
428
54%
428
22%
971
August16th to endNight
53%
693
18%
1839
10%
693
56%
693
34%
1167
September1st to 15thNight
43%
720
14%
1800
7%
720
45%
720
27%
1266
September16th to endNight
46%
717
20%
1962
14%
717
50%
717
30%
1268
October1st to 15thNight
30%
720
16%
2160
11%
720
38%
720
19%
1526
October16th to endNight
25%
708
10%
2216
6%
708
31%
708
13%
1723
November1st to 15thNight
26%
700
16%
2355
12%
700
34%
700
14%
1721
November16th to endNight
20%
720
8%
2520
6%
720
25%
720
8%
2002
December1st to 15thNight
16%
720
6%
2520
3%
720
21%
720
7%
2077
December16th to endNight
14%
768
10%
2688
4%
768
21%
768
8%
2198

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
18%10%47%6%34446%30%
48242
Night
18%11%47%5%24445%31%
47358
TransparencyDay
54%5%11%18%8%
47929
Night
54%5%11%18%8%
47189
SeeingDay
24%12%28%20%10%3
5551
Night
24%11%27%25%10%
14710

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
23%17%6%9%6%3422419%
1432
16th to endDay
14%15%6%9%6%44445%23%
1569
February1st to 15thDay
12%15%6%12%9%34345%21%
1575
16th to endDay
17%17%6%8%6%3323427%
1509
March1st to 15thDay
16%14%5%7%7%35%445%27%
1853
16th to endDay
14%8%45%5%34346%39%
2187
April1st to 15thDay
24%12%36%42233432%
2152
16th to endDay
22%8%46%423235%35%
2274
May1st to 15thDay
22%8%36%5%34336%31%
2511
16th to endDay
19%7%36%6%2445%5%32%
2618
June1st to 15thDay
22%7%37%6%36%5%5%7%26%
2520
16th to endDay
17%6%25%7%45%5%7%7%30%
2520
July1st to 15thDay
16%6%35%6%35%5%5%8%35%
2520
16th to endDay
12%6%36%7%45%46%9%33%
2654
August1st to 15thDay
13%7%26%7%36%46%6%33%
2448
16th to endDay
13%5%26%5%45%5%5%8%38%
2351
September1st to 15thDay
18%7%35%5%23346%39%
2160
16th to endDay
17%6%235%24346%43%
1996
October1st to 15thDay
22%8%26%5%33346%34%
1800
16th to endDay
29%12%38%5%2334422%
1677
November1st to 15thDay
18%9%46%5%2345%6%30%
1500
16th to endDay
26%15%5%9%41343422%
1440
December1st to 15thDay
24%19%5%9%6%3444414%
1440
16th to endDay
24%19%6%8%5%2423418%
1536
January1st to 15thNight
20%16%6%10%7%3444416%
2506
16th to endNight
13%16%6%9%7%35%5%4425%
2652
February1st to 15thNight
12%15%6%11%9%36%44422%
2285
16th to endNight
16%14%5%8%7%3445%425%
1964
March1st to 15thNight
19%13%5%7%7%2434426%
2084
16th to endNight
13%11%46%5%2433440%
2037
April1st to 15thNight
23%9%34423346%33%
1796
16th to endNight
21%8%245%23335%37%
1694
May1st to 15thNight
22%9%36%323335%35%
1440
16th to endNight
16%6%36%5%36%45%7%34%
1495
June1st to 15thNight
19%7%25%5%3446%7%33%
1440
16th to endNight
16%5%25%5%35%5%5%7%36%
1440
July1st to 15thNight
11%426%3345%6%7%44%
1440
16th to endNight
10%5%25%4245%6%9%43%
1514
August1st to 15thNight
12%6%245%35%5%6%9%38%
1511
16th to endNight
10%424325%45%8%47%
1839
September1st to 15thNight
17%6%35%42435%6%41%
1800
16th to endNight
17%5%25%423337%46%
1962
October1st to 15thNight
21%9%35%433335%37%
2160
16th to endNight
27%10%36%434345%25%
2216
November1st to 15thNight
20%10%37%6%34345%30%
2355
16th to endNight
24%14%48%6%2443422%
2520
December1st to 15thNight
22%18%6%8%5%2433418%
2520
16th to endNight
23%17%6%9%6%2333419%
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
71%37%11%4
1433
16th to endDay
63%5%10%13%6%
1569
February1st to 15thDay
65%49%14%4
1577
16th to endDay
62%39%14%9%
1509
March1st to 15thDay
61%311%14%8%1
1863
16th to endDay
47%49%19%14%4
2187
April1st to 15thDay
57%36%18%11%2
2152
16th to endDay
52%46%20%12%3
2274
May1st to 15thDay
54%46%17%14%1
2511
16th to endDay
51%6%11%17%11%1
2622
June1st to 15thDay
55%6%11%18%7%
2520
16th to endDay
48%8%12%19%9%
2520
July1st to 15thDay
44%6%14%23%10%
2371
16th to endDay
47%8%16%19%8%
2487
August1st to 15thDay
48%8%15%21%5%
2434
16th to endDay
42%7%16%23%8%
2351
September1st to 15thDay
45%5%13%23%11%
2160
16th to endDay
41%6%13%30%8%
1996
October1st to 15thDay
52%5%13%20%8%
1800
16th to endDay
65%5%11%12%4
1677
November1st to 15thDay
52%6%14%19%7%
1500
16th to endDay
66%410%12%5%
1440
December1st to 15thDay
72%6%9%9%2
1440
16th to endDay
71%48%10%4
1536
January1st to 15thNight
71%5%9%10%3
2506
16th to endNight
61%5%10%15%6%
2652
February1st to 15thNight
65%49%16%3
2287
16th to endNight
61%49%16%7%
1964
March1st to 15thNight
62%47%18%7%
2097
16th to endNight
47%48%20%15%3
2037
April1st to 15thNight
52%39%19%13%1
1796
16th to endNight
49%48%19%15%2
1694
May1st to 15thNight
52%36%18%15%4
1440
16th to endNight
47%7%11%19%11%1
1497
June1st to 15thNight
49%6%14%20%7%
1440
16th to endNight
45%7%12%21%13%
1440
July1st to 15thNight
37%6%15%25%15%
1360
16th to endNight
35%8%17%27%10%
1418
August1st to 15thNight
40%9%16%24%8%
1501
16th to endNight
33%7%19%30%8%
1839
September1st to 15thNight
43%6%12%25%11%
1800
16th to endNight
40%414%33%7%
1962
October1st to 15thNight
50%5%10%22%11%
2160
16th to endNight
59%6%12%16%4
2216
November1st to 15thNight
56%5%12%17%8%
2355
16th to endNight
65%5%10%13%3
2520
December1st to 15thNight
70%5%10%10%3
2520
16th to endNight
70%38%11%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
31%20%23%21%3
60
16th to endDay
34%7%31%20%41
69
February1st to 15thDay
26%23%40%7%2
90
16th to endDay
33%14%29%16%4
168
March1st to 15thDay
25%18%30%21%4
270
16th to endDay
21%17%28%20%10%2
288
April1st to 15thDay
31%18%25%15%8%
270
16th to endDay
27%19%24%15%10%2
270
May1st to 15thDay
32%9%28%18%7%3
288
16th to endDay
27%13%29%17%9%1
331
June1st to 15thDay
27%11%33%19%6%1
315
16th to endDay
15%10%33%26%11%2
315
July1st to 15thDay
16%7%34%28%10%2
305
16th to endDay
14%7%29%29%17%2
326
August1st to 15thDay
21%422%30%16%5%
313
16th to endDay
15%7%31%21%14%9%
332
September1st to 15thDay
21%8%23%21%13%10%
315
16th to endDay
18%9%22%22%16%9%
314
October1st to 15thDay
26%14%24%19%11%3
315
16th to endDay
38%11%26%15%8%
259
November1st to 15thDay
21%12%28%26%9%1
154
16th to endDay
43%8%33%13%1
60
December1st to 15thDay
28%21%35%13%1
60
16th to endDay
39%26%28%41
64
January1st to 15thNight
30%12%31%20%5%
720
16th to endNight
22%13%31%24%7%
768
February1st to 15thNight
19%14%36%22%6%
704
16th to endNight
24%16%29%23%5%
631
March1st to 15thNight
26%16%27%25%2
720
16th to endNight
18%16%26%26%11%
768
April1st to 15thNight
28%14%25%24%6%
718
16th to endNight
25%15%25%24%8%
614
May1st to 15thNight
28%6%28%25%10%
360
16th to endNight
18%8%34%28%10%
375
June1st to 15thNight
20%9%29%34%6%
360
16th to endNight
18%5%26%35%13%1
360
July1st to 15thNight
12%5%25%38%18%
340
16th to endNight
10%5%21%42%17%2
376
August1st to 15thNight
14%421%34%22%2
430
16th to endNight
12%424%33%22%2
693
September1st to 15thNight
21%425%27%18%2
720
16th to endNight
19%6%23%28%19%2
717
October1st to 15thNight
26%9%28%22%11%1
720
16th to endNight
35%10%24%20%8%
708
November1st to 15thNight
27%13%26%22%9%1
700
16th to endNight
33%14%24%19%7%
720
December1st to 15thNight
31%16%27%20%3
720
16th to endNight
33%13%28%18%41
768
Page generated at 2017-10-17 16:35:31. Version ac04

Copyright 2017 A. Danko


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