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 2018-02-13.

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%
15187
12%
48813
8%
15155
35%
15155
15%
35696

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
17%
780
6%
2716
3%
776
21%
776
6%
2248
January16th to endNight
21%
832
9%
2873
5%
832
27%
832
11%
2209
February1st to 15thNight
18%
753
9%
2444
4%
750
24%
750
9%
1934
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
24%
768
11%
2406
6%
768
31%
768
13%
1860
November1st to 15thNight
26%
760
15%
2557
11%
760
33%
760
13%
1879
November16th to endNight
20%
780
8%
2730
6%
780
25%
780
8%
2172
December1st to 15thNight
16%
780
7%
2730
3%
780
21%
780
7%
2244
December16th to endNight
16%
832
11%
2912
5%
832
23%
832
8%
2359

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%
49238
Night
18%11%47%5%24445%31%
48982
TransparencyDay
54%5%11%18%8%
48925
Night
55%5%11%18%8%
48813
SeeingDay
24%12%28%20%10%3
5833
Night
24%11%27%25%10%
15187

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
22%17%6%11%6%3422318%
1552
16th to endDay
14%15%6%9%6%4444423%
1700
February1st to 15thDay
12%15%6%12%9%3434421%
1683
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
28%11%27%6%23345%23%
1818
November1st to 15thDay
18%9%47%6%3345%6%29%
1628
16th to endDay
25%15%5%9%5%1343422%
1560
December1st to 15thDay
22%19%5%9%6%3444414%
1560
16th to endDay
22%18%6%8%5%2423419%
1664
January1st to 15thNight
20%16%6%10%7%3444417%
2716
16th to endNight
14%15%6%9%6%345%3425%
2873
February1st to 15thNight
11%15%7%11%9%35%44422%
2442
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
26%9%46%5%34345%26%
2406
November1st to 15thNight
20%10%37%6%34345%30%
2557
16th to endNight
24%14%48%6%2443422%
2730
December1st to 15thNight
22%18%6%8%5%2443418%
2730
16th to endNight
22%16%7%9%6%2333420%
2912

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%47%11%5%
1553
16th to endDay
63%5%10%13%6%
1700
February1st to 15thDay
66%49%14%4
1685
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
64%6%12%12%4
1818
November1st to 15thDay
53%6%13%18%7%
1628
16th to endDay
66%410%12%5%
1560
December1st to 15thDay
71%6%9%9%2
1560
16th to endDay
70%47%12%5%
1664
January1st to 15thNight
70%5%9%10%3
2716
16th to endNight
62%5%10%15%6%
2873
February1st to 15thNight
65%49%15%3
2444
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%17%4
2406
November1st to 15thNight
56%5%12%16%8%
2557
16th to endNight
65%5%10%13%3
2730
December1st to 15thNight
69%5%10%10%4
2730
16th to endNight
68%48%11%6%
2912

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%17%30%18%4
90
16th to endDay
32%10%33%19%2
104
February1st to 15thDay
26%24%39%7%1
126
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
35%13%26%15%8%
310
November1st to 15thDay
22%14%26%27%8%1
192
16th to endDay
37%21%31%8%1
90
December1st to 15thDay
26%20%38%13%1
90
16th to endDay
34%22%33%6%3
96
January1st to 15thNight
30%11%30%21%5%
780
16th to endNight
23%13%31%24%7%
832
February1st to 15thNight
18%14%36%22%6%
753
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
33%11%25%20%8%
768
November1st to 15thNight
28%12%26%22%9%1
760
16th to endNight
33%14%24%19%7%
780
December1st to 15thNight
32%16%27%19%3
780
16th to endNight
31%13%29%20%41
832
Page generated at 2018-02-13 20:46:03. Version ac04

Copyright 2018 A. Danko


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