Kemp's Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kemp's Lake clear sky chart from 2005-11-06 to 2024-01-27.

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
48%
23952
28%
74477
19%
23896
58%
23896
38%
40545

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 10thNight
35%
947
32%
2458
11%
946
48%
946
42%
1419
January11th to 20thNight
36%
950
30%
2470
11%
950
48%
950
39%
1442
January21st to endNight
33%
934
32%
2574
13%
934
46%
934
34%
1529
February1st to 10thNight
30%
720
29%
2160
11%
720
44%
720
31%
1266
February11th to 20thNight
28%
704
25%
2098
11%
700
39%
700
32%
1219
February21st to endNight
21%
592
31%
1776
8%
592
40%
592
32%
1011
March1st to 10thNight
30%
602
26%
2042
11%
602
45%
602
28%
1173
March11th to 20thNight
32%
540
25%
1980
14%
540
46%
540
26%
1117
March21st to endNight
29%
594
28%
2178
14%
594
48%
594
34%
1116
April1st to 10thNight
26%
540
27%
1980
12%
540
48%
540
32%
1032
April11th to 20thNight
28%
533
25%
1875
14%
533
45%
533
29%
1046
April21st to endNight
29%
540
31%
1656
13%
540
51%
540
37%
901
May1st to 10thNight
32%
540
28%
1620
16%
540
49%
540
36%
923
May11th to 20thNight
40%
531
21%
1594
15%
531
51%
531
34%
937
May21st to endNight
48%
583
24%
1745
17%
582
61%
582
36%
1007
June1st to 10thNight
67%
540
24%
1620
24%
540
74%
540
47%
840
June11th to 20thNight
68%
540
27%
1620
29%
540
74%
540
54%
779
June21st to endNight
72%
540
25%
1620
28%
540
75%
540
45%
857
July1st to 10thNight
73%
525
21%
1575
21%
525
76%
525
41%
867
July11th to 20thNight
83%
522
33%
1566
37%
522
87%
522
62%
703
July21st to endNight
87%
591
31%
1673
36%
558
89%
558
57%
781
August1st to 10thNight
92%
537
36%
1601
41%
534
94%
534
71%
672
August11th to 20thNight
77%
534
30%
1757
35%
534
79%
534
40%
931
August21st to endNight
85%
594
27%
2032
32%
594
86%
594
43%
995
September1st to 10thNight
75%
540
23%
1980
27%
540
76%
540
36%
1031
September11th to 20thNight
72%
540
24%
1980
27%
540
74%
540
32%
1075
September21st to endNight
73%
540
32%
1980
32%
540
78%
540
40%
960
October1st to 10thNight
72%
540
37%
1980
36%
540
78%
540
47%
893
October11th to 20thNight
55%
634
34%
2074
21%
634
65%
634
40%
1083
October21st to endNight
45%
792
33%
2376
19%
792
55%
792
39%
1299
November1st to 10thNight
52%
755
31%
2235
18%
755
61%
755
41%
1232
November11th to 20thNight
49%
950
29%
2470
14%
950
56%
950
45%
1397
November21st to endNight
38%
950
30%
2470
12%
950
47%
950
36%
1515
December1st to 10thNight
43%
950
32%
2470
15%
950
53%
950
40%
1451
December11th to 20thNight
35%
948
29%
2878
12%
948
45%
948
29%
1765
December21st to endNight
36%
1040
19%
4314
13%
1026
46%
1026
26%
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
10%5%2443445%7%53%
75011
Night
9%42332445%7%57%
75060
TransparencyDay
31%6%10%21%22%10%
74736
Night
27%5%10%21%23%13%
74855
SeeingDay
10%7%23%29%23%7%
13888
Night
10%7%30%37%15%1
23963

By Month

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 10thDay
10%5%2332235%6%58%
1707
11th to 20thDay
13%425%423345%55%
1710
21st to endDay
11%424423445%57%
1940
February1st to 10thDay
13%6%25%423346%52%
1800
11th to 20thDay
15%7%34422346%49%
1749
21st to endDay
16%6%23423335%54%
1480
March1st to 10thDay
15%7%25%5%24446%46%
1916
11th to 20thDay
11%6%35%5%3445%6%49%
1980
21st to endDay
12%434423447%53%
2178
April1st to 10thDay
10%6%25%5%2445%7%50%
1980
11th to 20thDay
14%6%25%433446%49%
2030
21st to endDay
11%5%25%5%3335%6%53%
2302
May1st to 10thDay
11%6%34435%5%5%6%48%
2340
11th to 20thDay
11%7%36%435%5%5%7%44%
2302
21st to endDay
11%5%35%7%35%6%6%8%39%
2531
June1st to 10thDay
5%324435%5%5%7%56%
2340
11th to 20thDay
42145%25%46%9%57%
2340
21st to endDay
6%3245%446%6%8%52%
2340
July1st to 10thDay
7%425%6%5%7%6%7%10%43%
2340
11th to 20thDay
42134245%5%8%62%
2340
21st to endDay
4324435%5%6%10%56%
2546
August1st to 10thDay
211242445%8%66%
2328
11th to 20thDay
8%425%5%345%6%8%51%
2139
21st to endDay
43245%46%5%6%9%51%
2322
September1st to 10thDay
10%425%5%35%446%51%
1980
11th to 20thDay
10%5%25%5%35%46%7%48%
1980
21st to endDay
7%423435%447%58%
1980
October1st to 10thDay
5%4234335%46%62%
1980
11th to 20thDay
9%5%23323335%62%
1866
21st to endDay
12%5%2432332362%
1980
November1st to 10thDay
12%5%24322336%57%
1839
11th to 20thDay
6%5%2332345%7%60%
1710
21st to endDay
13%6%26%423335%52%
1710
December1st to 10thDay
11%6%25%424446%52%
1710
11th to 20thDay
12%7%25%43445%5%49%
2161
21st to endDay
14%6%23322335%56%
3135
January1st to 10thNight
11%5%24323336%60%
2458
11th to 20thNight
11%424323336%59%
2470
21st to endNight
14%5%24323335%55%
2574
February1st to 10thNight
11%6%34423345%54%
2160
11th to 20thNight
15%6%25%323336%53%
2098
21st to endNight
16%5%12223345%55%
1776
March1st to 10thNight
14%5%2443446%7%48%
2042
11th to 20thNight
12%6%245%35%446%51%
1980
21st to endNight
8%424334447%57%
2178
April1st to 10thNight
7%5%15%425%46%7%54%
1980
11th to 20thNight
11%5%345%24446%53%
1875
21st to endNight
9%33342435%7%58%
1656
May1st to 10thNight
9%42442446%8%53%
1620
11th to 20thNight
9%5%234345%6%9%49%
1593
21st to endNight
9%32442447%11%49%
1745
June1st to 10thNight
222442445%9%62%
1620
11th to 20thNight
33123235%6%11%63%
1620
21st to endNight
432333447%9%58%
1620
July1st to 10thNight
5%3234245%5%10%56%
1620
11th to 20thNight
311121345%10%69%
1620
21st to endNight
211232347%12%63%
1772
August1st to 10thNight
111112449%76%
1611
11th to 20thNight
5%5%243345%7%9%55%
1757
21st to endNight
43133245%6%11%58%
2032
September1st to 10thNight
7%42333445%8%56%
1980
11th to 20thNight
9%5%244245%5%8%52%
1980
21st to endNight
442442445%9%59%
1980
October1st to 10thNight
4323224446%66%
1980
11th to 20thNight
10%413323445%61%
2074
21st to endNight
12%5%2322333361%
2376
November1st to 10thNight
9%5%2432334461%
2235
11th to 20thNight
6%42442345%6%60%
2470
21st to endNight
14%5%24423345%53%
2470
December1st to 10thNight
11%5%2332445%6%56%
2470
11th to 20thNight
12%7%34433445%51%
3036
21st to endNight
14%6%23323435%56%
4532

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 10thDay
29%37%18%30%13%
1708
11th to 20thDay
32%46%18%26%14%
1710
21st to endDay
30%47%16%27%16%
1940
February1st to 10thDay
36%46%15%22%17%
1800
11th to 20thDay
37%48%18%20%14%
1759
21st to endDay
34%36%15%23%20%
1480
March1st to 10thDay
40%5%8%13%23%12%
1916
11th to 20thDay
37%6%9%12%21%14%
1980
21st to endDay
32%5%9%20%22%13%
2178
April1st to 10thDay
35%5%9%19%18%14%
1980
11th to 20thDay
36%5%8%18%21%12%
2030
21st to endDay
34%5%8%19%26%9%
2302
May1st to 10thDay
36%6%9%20%20%9%
2340
11th to 20thDay
38%8%11%20%19%5%
2306
21st to endDay
40%9%13%21%15%2
2531
June1st to 10thDay
25%7%13%29%21%4
2340
11th to 20thDay
23%7%14%30%18%7%
2340
21st to endDay
28%8%13%22%23%6%
2340
July1st to 10thDay
33%9%18%27%12%1
2276
11th to 20thDay
18%7%15%30%25%5%
2271
21st to endDay
21%7%18%36%17%1
2405
August1st to 10thDay
15%6%16%36%24%3
2314
11th to 20thDay
31%9%13%28%14%5%
2139
21st to endDay
27%8%15%28%17%4
2322
September1st to 10thDay
33%6%11%20%22%9%
1980
11th to 20thDay
34%6%13%20%21%6%
1980
21st to endDay
26%6%10%21%24%13%
1980
October1st to 10thDay
24%5%11%22%23%15%
1980
11th to 20thDay
26%48%16%25%21%
1866
21st to endDay
29%4417%26%21%
1980
November1st to 10thDay
31%48%21%24%12%
1839
11th to 20thDay
25%5%9%19%26%16%
1710
21st to endDay
36%45%18%23%15%
1710
December1st to 10thDay
33%47%20%24%11%
1710
11th to 20thDay
36%6%7%13%24%14%
2159
21st to endDay
31%36%16%28%16%
3135
January1st to 10thNight
28%35%17%28%18%
2458
11th to 20thNight
29%35%20%26%17%
2470
21st to endNight
33%45%15%24%20%
2574
February1st to 10thNight
33%5%7%13%21%20%
2160
11th to 20thNight
34%37%16%23%16%
2098
21st to endNight
31%5%6%15%20%22%
1776
March1st to 10thNight
35%410%15%24%12%
2042
11th to 20thNight
35%5%9%15%21%15%
1980
21st to endNight
28%5%12%19%24%12%
2178
April1st to 10thNight
29%5%10%20%20%16%
1980
11th to 20thNight
32%6%10%15%21%16%
1875
21st to endNight
27%5%11%21%26%9%
1656
May1st to 10thNight
29%6%11%22%22%9%
1620
11th to 20thNight
30%8%15%25%16%5%
1594
21st to endNight
28%8%16%29%17%2
1746
June1st to 10thNight
19%8%15%32%22%4
1620
11th to 20thNight
16%6%16%32%21%8%
1620
21st to endNight
21%8%13%28%24%6%
1620
July1st to 10thNight
24%8%19%32%15%2
1575
11th to 20thNight
11%6%18%33%27%6%
1566
21st to endNight
13%7%22%38%19%1
1673
August1st to 10thNight
7%5%17%39%28%4
1601
11th to 20thNight
24%8%15%30%19%5%
1757
21st to endNight
19%8%17%31%19%5%
2032
September1st to 10thNight
27%7%13%22%21%11%
1980
11th to 20thNight
31%6%15%22%20%7%
1980
21st to endNight
23%5%10%23%23%15%
1980
October1st to 10thNight
19%412%27%20%18%
1980
11th to 20thNight
26%49%15%22%23%
2074
21st to endNight
29%35%16%25%22%
2376
November1st to 10thNight
28%47%20%26%15%
2235
11th to 20thNight
25%5%9%21%23%18%
2470
21st to endNight
34%48%16%24%15%
2470
December1st to 10thNight
29%5%10%19%25%13%
2470
11th to 20thNight
35%45%13%25%17%
3037
21st to endNight
32%45%15%26%19%
4532

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 10thDay
13%15%40%27%4
270
11th to 20thDay
18%12%36%26%6%2
270
21st to endDay
13%15%43%22%6%1
282
February1st to 10thDay
18%18%37%24%4
240
11th to 20thDay
24%13%42%18%4
240
21st to endDay
23%19%39%17%21
198
March1st to 10thDay
18%18%42%20%3
240
11th to 20thDay
14%20%37%22%5%1
240
21st to endDay
11%16%45%23%5%
264
April1st to 10thDay
13%17%43%21%5%
240
11th to 20thDay
18%14%41%22%5%
308
21st to endDay
14%16%40%21%8%1
562
May1st to 10thDay
10%13%37%32%9%
603
11th to 20thDay
16%8%29%30%14%3
625
21st to endDay
14%5%26%37%16%3
679
June1st to 10thDay
5%216%43%27%7%
630
11th to 20thDay
3117%50%24%5%
630
21st to endDay
5%112%38%34%11%
630
July1st to 10thDay
6%26%35%37%14%
621
11th to 20thDay
2331%50%13%
618
21st to endDay
315%30%46%16%
684
August1st to 10thDay
21431%44%17%
626
11th to 20thDay
9%2427%41%17%
453
21st to endDay
5%15%24%40%24%
441
September1st to 10thDay
8%6%16%44%26%
270
11th to 20thDay
327%19%44%25%
270
21st to endDay
10%27%25%40%15%
270
October1st to 10thDay
3214%35%37%9%
270
11th to 20thDay
9%430%31%22%3
270
21st to endDay
21%11%25%20%21%2
297
November1st to 10thDay
17%5%31%31%11%5%
270
11th to 20thDay
11%12%27%31%15%4
270
21st to endDay
17%19%31%23%9%2
270
December1st to 10thDay
14%11%33%29%10%3
270
11th to 20thDay
14%13%41%25%8%
270
21st to endDay
17%14%34%27%6%2
297
January1st to 10thNight
13%8%40%31%6%
950
11th to 20thNight
14%11%35%33%7%
950
21st to endNight
15%13%36%31%6%
934
February1st to 10thNight
15%11%41%29%4
720
11th to 20thNight
17%11%41%28%3
704
21st to endNight
19%13%45%21%2
592
March1st to 10thNight
16%12%40%29%2
602
11th to 20thNight
14%10%40%31%5%
540
21st to endNight
8%12%50%26%4
594
April1st to 10thNight
10%9%52%26%3
540
11th to 20thNight
13%10%46%28%4
533
21st to endNight
9%12%49%25%6%
540
May1st to 10thNight
9%9%47%30%5%
540
11th to 20thNight
11%5%40%32%11%1
531
21st to endNight
9%335%40%12%1
584
June1st to 10thNight
1222%51%22%1
540
11th to 20thNight
4223%58%13%
540
21st to endNight
4115%52%26%2
540
July1st to 10thNight
5%211%50%30%3
525
11th to 20thNight
3110%51%34%2
522
21st to endNight
116%53%37%2
591
August1st to 10thNight
1455%38%2
537
11th to 20thNight
7%17%43%39%3
534
21st to endNight
415%40%44%6%
594
September1st to 10thNight
7%110%44%33%5%
540
11th to 20thNight
11%18%43%35%3
540
21st to endNight
6%114%41%34%3
540
October1st to 10thNight
5%117%48%26%2
540
11th to 20thNight
11%426%42%14%2
634
21st to endNight
15%8%29%32%16%1
792
November1st to 10thNight
10%429%39%16%1
755
11th to 20thNight
7%8%32%38%14%
950
21st to endNight
16%9%34%31%10%1
950
December1st to 10thNight
12%8%33%39%8%
950
11th to 20thNight
15%10%35%34%5%
950
21st to endNight
13%10%38%31%7%
1045
Page generated at 2024-01-24 08:37:27. Version ac07

Copyright 2024 Attilla Danko


Kemp's Lake Clear Sky Chart |Charts Home