Oxtongue Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Oxtongue Lake clear sky chart from 2005-11-05 to 2017-11-30.

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
28%
14977
12%
47482
7%
14944
33%
14944
15%
34818

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
11%
720
5%
2506
2%
716
15%
716
5%
2116
January16th to endNight
18%
768
11%
2535
6%
768
25%
768
10%
2028
February1st to 15thNight
13%
703
8%
2287
3%
701
20%
701
8%
1851
February16th to endNight
17%
631
11%
2036
4%
631
25%
631
10%
1586
March1st to 15thNight
17%
720
12%
1989
5%
720
24%
720
14%
1529
March16th to endNight
30%
768
19%
2112
9%
768
37%
768
23%
1444
April1st to 15thNight
22%
718
14%
1796
5%
718
27%
718
19%
1355
April16th to endNight
29%
561
18%
1641
9%
561
35%
561
21%
1146
May1st to 15thNight
34%
429
16%
1509
13%
429
42%
429
20%
989
May16th to endNight
36%
374
13%
1497
9%
374
48%
374
20%
902
June1st to 15thNight
37%
360
9%
1404
8%
360
43%
360
17%
919
June16th to endNight
47%
360
10%
1260
10%
360
51%
360
20%
821
July1st to 15thNight
50%
340
15%
1238
18%
340
56%
340
29%
690
July16th to endNight
49%
409
15%
1449
15%
385
55%
385
26%
852
August1st to 15thNight
53%
539
15%
1609
12%
536
57%
536
29%
1012
August16th to endNight
49%
624
17%
1770
8%
624
54%
624
31%
1108
September1st to 15thNight
44%
720
15%
1800
7%
720
47%
720
30%
1230
September16th to endNight
46%
717
20%
2002
14%
717
50%
717
28%
1300
October1st to 15thNight
30%
720
16%
2160
10%
720
38%
720
19%
1528
October16th to endNight
18%
768
9%
2304
4%
768
25%
768
11%
1854
November1st to 15thNight
24%
760
14%
2642
11%
760
31%
760
14%
1911
November16th to endNight
17%
780
9%
2728
6%
780
23%
780
8%
2195
December1st to 15thNight
12%
720
5%
2520
1%
720
16%
720
5%
2171
December16th to endNight
10%
768
7%
2688
3%
768
16%
768
6%
2281

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%11%47%5%34446%29%
48935
Night
18%12%47%5%34446%29%
47649
Cloud CoverDay
19%11%47%5%34446%29%
48945
Night
18%12%47%5%24445%29%
47654
TransparencyDay
56%410%18%9%1
48620
Night
56%411%18%9%
47482
SeeingDay
25%12%28%20%9%3
5892
Night
24%12%28%23%9%1
14979

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%18%8%10%5%3333417%
1432
16th to endDay
15%17%8%10%7%45%335%17%
1689
February1st to 15thDay
13%18%8%14%8%3423419%
1575
16th to endDay
15%17%7%10%6%25%43321%
1436
March1st to 15thDay
16%13%5%9%6%4445%5%25%
1957
16th to endDay
13%9%48%6%24345%36%
2112
April1st to 15thDay
23%13%35%423445%30%
2151
16th to endDay
20%11%35%323335%37%
2330
May1st to 15thDay
20%8%46%5%34447%30%
2442
16th to endDay
17%6%244245%5%7%37%
2618
June1st to 15thDay
23%8%35%5%34447%28%
2553
16th to endDay
19%7%25%426%5%6%8%31%
2700
July1st to 15thDay
17%5%25%5%35%45%8%36%
2646
16th to endDay
14%6%35%6%36%5%6%10%32%
2620
August1st to 15thDay
15%7%36%6%445%47%33%
2340
16th to endDay
16%6%25%6%45%5%48%34%
2420
September1st to 15thDay
20%7%26%5%24446%35%
2160
16th to endDay
19%7%24423446%39%
1956
October1st to 15thDay
27%7%36%5%33336%30%
1800
16th to endDay
34%12%26%423346%19%
1920
November1st to 15thDay
22%13%47%5%34445%25%
1544
16th to endDay
25%19%7%8%5%2433417%
1558
December1st to 15thDay
21%23%7%10%6%2323413%
1440
16th to endDay
20%23%8%11%42434413%
1536
January1st to 15thNight
20%19%8%11%6%3333414%
2506
16th to endNight
14%17%8%10%7%33435%19%
2535
February1st to 15thNight
12%17%7%12%7%35%445%18%
2285
16th to endNight
16%16%7%10%7%44335%22%
2036
March1st to 15thNight
17%13%5%7%6%24335%28%
1977
16th to endNight
14%9%45%5%24445%39%
2112
April1st to 15thNight
22%13%45%423235%32%
1796
16th to endNight
18%10%35%424446%35%
1641
May1st to 15thNight
19%8%2443435%7%35%
1509
16th to endNight
14%6%244345%5%8%40%
1495
June1st to 15thNight
16%8%35%4335%5%6%35%
1404
16th to endNight
15%5%25%5%35%5%5%7%36%
1260
July1st to 15thNight
11%42442345%7%49%
1312
16th to endNight
11%424415%6%6%9%43%
1547
August1st to 15thNight
12%424425%5%48%44%
1620
16th to endNight
12%42443445%7%45%
1770
September1st to 15thNight
15%5%244245%5%6%41%
1800
16th to endNight
17%5%24423446%45%
2002
October1st to 15thNight
22%7%25%5%34346%34%
2160
16th to endNight
29%11%47%5%33345%22%
2304
November1st to 15thNight
22%11%46%423346%29%
2642
16th to endNight
24%16%5%7%6%3333420%
2728
December1st to 15thNight
21%23%7%9%5%3433312%
2520
16th to endNight
22%19%9%10%5%3333413%
2688

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
21%18%8%10%6%33145%17%
1432
16th to endDay
14%17%8%10%8%45%235%18%
1689
February1st to 15thDay
13%18%7%15%8%3423419%
1575
16th to endDay
15%18%8%10%6%35%33321%
1436
March1st to 15thDay
16%13%49%7%45%345%24%
1968
16th to endDay
12%10%47%5%34345%36%
2111
April1st to 15thDay
23%12%35%5%23345%30%
2151
16th to endDay
20%10%35%423335%37%
2330
May1st to 15thDay
20%8%36%5%24446%31%
2442
16th to endDay
17%7%25%4245%47%37%
2618
June1st to 15thDay
23%8%36%43445%6%28%
2553
16th to endDay
18%7%25%5%35%5%5%8%32%
2700
July1st to 15thDay
17%5%25%5%35%45%8%35%
2646
16th to endDay
15%6%25%5%36%47%9%32%
2620
August1st to 15thDay
14%8%36%6%35%5%5%6%33%
2340
16th to endDay
15%6%26%5%45%5%5%8%34%
2420
September1st to 15thDay
20%7%26%424446%35%
2160
16th to endDay
18%7%24424446%39%
1956
October1st to 15thDay
27%9%36%433336%30%
1800
16th to endDay
33%12%36%5%23345%19%
1920
November1st to 15thDay
21%14%46%6%24445%25%
1544
16th to endDay
24%19%7%8%5%2334417%
1558
December1st to 15thDay
21%23%9%9%6%2333413%
1440
16th to endDay
20%22%9%10%43233413%
1536
January1st to 15thNight
20%20%8%10%7%2433414%
2506
16th to endNight
14%17%8%11%7%33435%19%
2535
February1st to 15thNight
12%16%7%12%8%35%445%18%
2278
16th to endNight
16%16%6%10%6%3433422%
2036
March1st to 15thNight
17%13%47%7%34335%28%
1989
16th to endNight
13%10%45%5%24445%39%
2112
April1st to 15thNight
22%13%45%43233431%
1796
16th to endNight
18%10%25%5%24446%35%
1641
May1st to 15thNight
19%7%25%42346%7%35%
1509
16th to endNight
14%5%25%435%5%6%8%39%
1495
June1st to 15thNight
16%7%35%5%245%5%6%35%
1404
16th to endNight
15%6%25%6%35%5%5%7%36%
1260
July1st to 15thNight
11%424424446%49%
1312
16th to endNight
10%5%15%425%6%5%8%43%
1547
August1st to 15thNight
12%415%4345%5%7%45%
1620
16th to endNight
12%415%4245%5%7%45%
1770
September1st to 15thNight
16%5%244236%5%7%40%
1800
16th to endNight
17%5%14423346%44%
2002
October1st to 15thNight
21%8%25%425%446%34%
2160
16th to endNight
28%13%36%5%3333422%
2304
November1st to 15thNight
22%11%45%433346%29%
2642
16th to endNight
24%16%5%6%6%2434420%
2728
December1st to 15thNight
22%22%8%9%6%2343313%
2520
16th to endNight
23%19%9%10%6%3333314%
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
72%29%9%5%
1433
16th to endDay
69%36%11%7%1
1689
February1st to 15thDay
70%37%12%5%
1577
16th to endDay
67%29%11%8%
1436
March1st to 15thDay
61%411%14%7%
1968
16th to endDay
50%39%18%14%3
2112
April1st to 15thDay
56%48%18%10%1
2151
16th to endDay
50%37%21%14%2
2330
May1st to 15thDay
53%310%18%12%1
2442
16th to endDay
45%5%12%21%12%2
2622
June1st to 15thDay
55%5%9%19%9%
2553
16th to endDay
48%7%13%20%10%1
2700
July1st to 15thDay
43%5%11%27%11%1
2491
16th to endDay
47%6%12%23%9%
2455
August1st to 15thDay
50%5%14%19%9%
2327
16th to endDay
47%5%14%24%7%
2420
September1st to 15thDay
49%413%22%9%
2160
16th to endDay
45%5%12%28%8%
1956
October1st to 15thDay
57%310%18%9%
1800
16th to endDay
67%410%12%4
1920
November1st to 15thDay
60%6%11%14%6%
1544
16th to endDay
72%39%10%31
1558
December1st to 15thDay
76%38%8%2
1440
16th to endDay
74%36%9%4
1536
January1st to 15thNight
74%38%8%4
2506
16th to endNight
67%37%12%8%1
2535
February1st to 15thNight
68%49%12%5%
2287
16th to endNight
65%38%15%7%
2036
March1st to 15thNight
60%311%15%8%
1989
16th to endNight
46%310%20%16%2
2112
April1st to 15thNight
56%27%19%12%1
1796
16th to endNight
49%37%20%16%2
1641
May1st to 15thNight
47%410%20%14%2
1509
16th to endNight
40%7%14%22%13%1
1497
June1st to 15thNight
47%5%13%19%13%
1404
16th to endNight
44%5%13%23%11%
1260
July1st to 15thNight
32%6%12%29%18%1
1238
16th to endNight
36%6%15%28%12%
1449
August1st to 15thNight
36%7%17%26%11%
1609
16th to endNight
36%5%17%29%9%
1770
September1st to 15thNight
40%7%16%25%10%
1800
16th to endNight
40%5%14%31%8%
2002
October1st to 15thNight
51%5%10%20%12%
2160
16th to endNight
65%5%10%14%4
2304
November1st to 15thNight
56%414%16%6%
2642
16th to endNight
68%49%12%4
2728
December1st to 15thNight
76%47%9%2
2520
16th to endNight
75%37%7%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
30%25%33%6%5%
60
16th to endDay
29%12%38%16%3
89
February1st to 15thDay
33%24%35%6%
90
16th to endDay
40%12%35%11%
95
March1st to 15thDay
24%20%31%20%21
270
16th to endDay
20%16%32%19%9%1
288
April1st to 15thDay
25%18%28%18%8%
270
16th to endDay
28%16%25%17%7%4
270
May1st to 15thDay
34%7%26%19%7%4
288
16th to endDay
24%15%29%17%9%2
331
June1st to 15thDay
28%10%29%22%7%1
348
16th to endDay
21%13%32%21%8%2
495
July1st to 15thDay
16%9%30%27%11%3
425
16th to endDay
17%9%29%26%13%3
326
August1st to 15thDay
18%426%30%9%8%
313
16th to endDay
23%5%20%27%15%7%
332
September1st to 15thDay
20%7%25%20%19%6%
315
16th to endDay
21%7%23%25%16%5%
314
October1st to 15thDay
30%14%23%21%8%2
315
16th to endDay
38%15%26%15%3
336
November1st to 15thDay
29%21%28%15%4
108
16th to endDay
38%20%34%5%1
90
December1st to 15thDay
41%18%23%15%1
60
16th to endDay
29%40%25%31
64
January1st to 15thNight
31%19%29%15%3
720
16th to endNight
23%13%34%19%7%
768
February1st to 15thNight
21%19%35%18%4
704
16th to endNight
24%19%31%19%5%
631
March1st to 15thNight
25%18%31%20%3
720
16th to endNight
18%15%31%23%10%1
768
April1st to 15thNight
28%13%31%20%6%
718
16th to endNight
25%11%28%24%9%
561
May1st to 15thNight
25%6%27%26%12%1
429
16th to endNight
16%9%34%30%9%
375
June1st to 15thNight
21%6%29%30%10%
360
16th to endNight
17%8%23%41%10%
360
July1st to 15thNight
12%426%38%17%
340
16th to endNight
11%326%38%18%
409
August1st to 15thNight
14%420%36%21%3
539
16th to endNight
15%424%32%20%2
624
September1st to 15thNight
19%426%27%17%4
720
16th to endNight
20%5%22%29%19%2
717
October1st to 15thNight
25%11%27%23%9%1
720
16th to endNight
37%12%27%17%4
768
November1st to 15thNight
28%13%27%20%8%
760
16th to endNight
34%15%26%17%5%
780
December1st to 15thNight
33%19%28%14%3
720
16th to endNight
33%15%30%14%31
768
Page generated at 2017-12-01 12:13:42. Version ac04

Copyright 2017 A. Danko


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