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 2005-11-05 to 2017-10-31.

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
51%
15653
29%
47444
20%
15609
60%
15609
40%
25705

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
38%
896
30%
2327
12%
895
48%
895
39%
1380
January16th to endNight
38%
900
34%
2436
14%
900
51%
900
39%
1401
February1st to 15thNight
35%
704
30%
2106
14%
698
48%
698
35%
1185
February16th to endNight
25%
632
32%
1894
11%
632
42%
632
38%
1014
March1st to 15thNight
35%
582
27%
2022
14%
582
50%
582
30%
1127
March16th to endNight
33%
576
27%
2112
15%
576
50%
576
33%
1085
April1st to 15thNight
30%
539
26%
1977
13%
539
50%
539
34%
1022
April16th to endNight
31%
540
29%
1710
14%
540
50%
540
36%
942
May1st to 15thNight
32%
539
24%
1620
14%
539
48%
539
35%
943
May16th to endNight
50%
562
25%
1684
19%
561
61%
561
38%
954
June1st to 15thNight
70%
540
24%
1620
25%
540
76%
540
53%
788
June16th to endNight
71%
540
25%
1620
28%
540
74%
540
44%
860
July1st to 15thNight
78%
510
24%
1530
26%
510
81%
510
48%
787
July16th to endNight
86%
564
31%
1594
35%
531
89%
531
53%
779
August1st to 15thNight
92%
539
34%
1655
41%
536
92%
536
59%
755
August16th to endNight
80%
573
26%
1945
32%
573
80%
573
36%
1045
September1st to 15thNight
76%
540
21%
1980
25%
540
77%
540
34%
1062
September16th to endNight
72%
537
30%
1980
31%
537
75%
537
35%
1027
October1st to 15thNight
68%
543
35%
1983
32%
543
75%
543
44%
937
October16th to endNight
56%
768
36%
2304
22%
768
65%
768
49%
1142
November1st to 15thNight
53%
769
31%
2169
17%
769
61%
769
45%
1182
November16th to endNight
45%
900
33%
2340
15%
900
54%
900
43%
1344
December1st to 15thNight
42%
900
31%
2340
15%
900
50%
900
39%
1404
December16th to endNight
37%
960
28%
2496
12%
960
47%
960
35%
1540

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
9%424424446%52%
48295
Night
8%313323347%57%
47646
Cloud CoverDay
9%424424446%52%
48293
Night
8%313323347%57%
47646
TransparencyDay
31%5%10%21%21%10%
47993
Night
26%410%21%22%13%
47451
SeeingDay
10%419%31%26%7%
5610
Night
9%5%29%37%16%1
15659

By Month

Percentage Cloud Cover SW (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
13%42431233454%
1611
16th to endDay
11%323313346%57%
1797
February1st to 15thDay
10%5%24313346%55%
1750
16th to endDay
12%5%22213245%56%
1580
March1st to 15thDay
14%6%24423245%50%
1938
16th to endDay
12%434312246%53%
2112
April1st to 15thDay
9%424423447%52%
1971
16th to endDay
11%5%35%323346%50%
2247
May1st to 15thDay
12%6%24435%45%6%43%
2331
16th to endDay
11%5%35%5%35%6%6%7%40%
2430
June1st to 15thDay
5%21332445%8%56%
2340
16th to endDay
6%325%5%25%5%6%9%48%
2340
July1st to 15thDay
7%213446%5%6%9%48%
2340
16th to endDay
5%214426%5%5%10%50%
2466
August1st to 15thDay
3212425%45%8%59%
2291
16th to endDay
8%425%5%45%6%6%8%42%
2256
September1st to 15thDay
10%4245%2445%7%48%
1980
16th to endDay
9%42342445%7%50%
1980
October1st to 15thDay
6%5%23323345%59%
1962
16th to endDay
6%31221222470%
1919
November1st to 15thDay
9%424312336%56%
1686
16th to endDay
11%31421222461%
1620
December1st to 15thDay
14%5%2441334452%
1620
16th to endDay
12%7%24323446%48%
1728
January1st to 15thNight
11%5%2431223457%
2327
16th to endNight
13%312312335%58%
2436
February1st to 15thNight
10%41332233459%
2102
16th to endNight
12%323312245%59%
1894
March1st to 15thNight
12%423324346%51%
2022
16th to endNight
8%412324347%56%
2112
April1st to 15thNight
6%41442445%7%55%
1977
16th to endNight
8%323413347%55%
1710
May1st to 15thNight
8%41442345%8%51%
1619
16th to endNight
6%42342446%10%50%
1683
June1st to 15thNight
111331335%9%65%
1620
16th to endNight
422232436%9%58%
1620
July1st to 15thNight
321331435%10%59%
1620
16th to endNight
21231346%11%60%
1702
August1st to 15thNight
111121236%8%69%
1665
16th to endNight
6%4133246%6%10%51%
1945
September1st to 15thNight
8%314325%45%8%52%
1980
16th to endNight
7%414324348%53%
1980
October1st to 15thNight
6%312213446%63%
1983
16th to endNight
7%21221333367%
2304
November1st to 15thNight
5%41332334462%
2169
16th to endNight
10%41331224460%
2340
December1st to 15thNight
12%6%1321335%5%54%
2340
16th to endNight
11%5%24323445%52%
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
13%424312335%54%
1611
16th to endDay
11%313322345%57%
1797
February1st to 15thDay
10%5%24312345%56%
1750
16th to endDay
12%422313235%56%
1580
March1st to 15thDay
13%6%24423335%50%
1938
16th to endDay
12%434312336%53%
2110
April1st to 15thDay
8%5%14423447%53%
1971
16th to endDay
11%5%25%423345%50%
2247
May1st to 15thDay
12%6%34435%45%6%44%
2331
16th to endDay
11%5%35%5%25%6%6%7%40%
2430
June1st to 15thDay
5%21332445%8%57%
2340
16th to endDay
6%3245%345%5%8%49%
2340
July1st to 15thDay
6%2145%36%5%6%8%48%
2340
16th to endDay
5%314425%5%5%10%50%
2466
August1st to 15thDay
3112425%45%7%59%
2291
16th to endDay
8%425%5%46%6%6%8%42%
2256
September1st to 15thDay
10%4245%3445%6%48%
1980
16th to endDay
9%424424447%50%
1980
October1st to 15thDay
7%5%13322445%59%
1962
16th to endDay
6%31221222370%
1919
November1st to 15thDay
9%424322335%57%
1686
16th to endDay
10%41421222461%
1620
December1st to 15thDay
13%5%2431334452%
1620
16th to endDay
12%7%24323346%48%
1728
January1st to 15thNight
11%5%14312335%57%
2327
16th to endNight
13%412212325%58%
2436
February1st to 15thNight
10%42331323459%
2102
16th to endNight
12%313212245%58%
1894
March1st to 15thNight
12%42332435%6%51%
2022
16th to endNight
8%422324347%56%
2112
April1st to 15thNight
5%32442435%7%55%
1977
16th to endNight
8%233413347%55%
1710
May1st to 15thNight
8%41442345%9%50%
1619
16th to endNight
7%2234245%6%10%50%
1683
June1st to 15thNight
1213223349%65%
1620
16th to endNight
431332336%9%58%
1620
July1st to 15thNight
321231445%10%59%
1620
16th to endNight
21231347%11%60%
1702
August1st to 15thNight
111121235%9%68%
1665
16th to endNight
5%4133245%6%10%51%
1945
September1st to 15thNight
8%323325%45%8%53%
1980
16th to endNight
7%42432345%8%53%
1980
October1st to 15thNight
6%312213446%63%
1983
16th to endNight
7%21222333467%
2304
November1st to 15thNight
5%413323345%62%
2169
16th to endNight
10%41331234460%
2340
December1st to 15thNight
12%6%1321235%5%54%
2340
16th to endNight
11%424423445%52%
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
33%36%15%27%13%
1612
16th to endDay
28%38%16%26%16%
1797
February1st to 15thDay
31%36%16%23%18%
1751
16th to endDay
30%26%19%23%16%
1580
March1st to 15thDay
37%48%12%24%12%
1938
16th to endDay
33%48%18%23%10%
2112
April1st to 15thDay
32%49%20%18%15%
1971
16th to endDay
35%47%18%23%11%
2247
May1st to 15thDay
40%5%9%17%17%9%
2331
16th to endDay
39%8%11%19%18%3
2434
June1st to 15thDay
24%6%11%26%24%6%
2340
16th to endDay
31%6%14%23%18%5%
2340
July1st to 15thDay
29%7%17%27%15%2
2201
16th to endDay
25%7%17%31%16%1
2311
August1st to 15thDay
21%6%14%33%21%2
2277
16th to endDay
36%8%15%23%12%3
2256
September1st to 15thDay
35%5%11%21%20%5%
1980
16th to endDay
31%6%10%20%20%9%
1980
October1st to 15thDay
26%411%22%20%14%
1962
16th to endDay
20%25%17%30%23%
1919
November1st to 15thDay
29%38%23%22%12%
1686
16th to endDay
28%35%15%25%22%
1620
December1st to 15thDay
35%37%18%24%10%
1620
16th to endDay
35%38%17%24%10%
1728
January1st to 15thNight
30%2418%24%18%
2327
16th to endNight
29%3416%26%19%
2436
February1st to 15thNight
29%46%13%23%23%
2112
16th to endNight
27%37%17%23%20%
1894
March1st to 15thNight
32%410%13%23%15%
2022
16th to endNight
28%411%19%24%10%
2112
April1st to 15thNight
27%5%10%18%20%17%
1977
16th to endNight
28%5%11%18%24%11%
1710
May1st to 15thNight
29%7%12%21%19%10%
1620
16th to endNight
28%6%16%25%19%4
1685
June1st to 15thNight
16%6%14%31%24%7%
1620
16th to endNight
22%6%13%28%22%5%
1620
July1st to 15thNight
19%6%19%33%18%2
1530
16th to endNight
15%7%21%33%19%2
1594
August1st to 15thNight
12%5%16%35%25%3
1655
16th to endNight
25%8%17%27%15%4
1945
September1st to 15thNight
28%6%14%21%21%7%
1980
16th to endNight
28%5%10%22%21%11%
1980
October1st to 15thNight
22%313%26%17%16%
1983
16th to endNight
21%36%15%28%25%
2304
November1st to 15thNight
24%48%23%24%15%
2169
16th to endNight
27%37%14%23%22%
2340
December1st to 15thNight
31%39%18%24%13%
2340
16th to endNight
33%47%15%24%14%
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
17%12%31%30%7%1
90
16th to endDay
8%12%44%26%6%2
96
February1st to 15thDay
317%31%38%8%
90
16th to endDay
11%8%50%25%21
81
March1st to 15thDay
22%11%35%23%7%
90
16th to endDay
6%6%38%35%13%
96
April1st to 15thDay
14%11%34%31%8%
90
16th to endDay
15%12%41%21%8%
357
May1st to 15thDay
15%10%36%26%9%1
468
16th to endDay
17%329%31%13%3
517
June1st to 15thDay
6%115%47%24%5%
495
16th to endDay
5%11%41%31%9%
495
July1st to 15thDay
6%5%41%38%6%
475
16th to endDay
4429%45%15%
515
August1st to 15thDay
4227%48%17%
444
16th to endDay
14%15%27%37%13%
296
September1st to 15thDay
2317%48%26%
135
16th to endDay
11%8%16%48%14%
135
October1st to 15thDay
11431%47%13%
135
16th to endDay
12%6%20%28%28%3
144
November1st to 15thDay
26%6%23%26%13%3
90
16th to endDay
20%20%27%17%12%2
90
December1st to 15thDay
26%7%26%24%8%5%
90
16th to endDay
11%18%33%31%5%
96
January1st to 15thNight
13%9%35%33%8%
900
16th to endNight
14%9%36%33%6%
900
February1st to 15thNight
12%10%38%33%4
704
16th to endNight
14%10%46%25%3
632
March1st to 15thNight
15%9%37%33%3
582
16th to endNight
8%9%46%30%5%
576
April1st to 15thNight
8%7%51%29%3
539
16th to endNight
10%7%47%27%7%
540
May1st to 15thNight
10%7%47%28%6%
540
16th to endNight
8%135%39%14%
563
June1st to 15thNight
1121%52%21%1
540
16th to endNight
4115%52%24%2
540
July1st to 15thNight
310%50%32%2
510
16th to endNight
3447%40%3
564
August1st to 15thNight
1242%50%2
539
16th to endNight
8%437%42%5%
573
September1st to 15thNight
8%7%42%36%5%
540
16th to endNight
9%10%40%34%3
537
October1st to 15thNight
6%119%44%24%3
543
16th to endNight
9%328%36%19%2
768
November1st to 15thNight
8%430%37%17%1
769
16th to endNight
12%6%32%35%12%
900
December1st to 15thNight
15%7%31%36%8%
900
16th to endNight
14%9%36%33%6%
960
Page generated at 2017-11-01 16:23:30. Version ac04

Copyright 2017 A. Danko


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