Franklinton
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Franklinton clear sky chart from 2005-11-05 to 2017-03-24.

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
52%
14689
23%
45391
17%
14643
58%
14643
30%
27262

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
34%
900
25%
2327
9%
895
44%
895
29%
1496
January16th to endNight
30%
846
25%
2382
11%
846
40%
846
25%
1573
February1st to 15thNight
33%
704
26%
2112
11%
701
45%
701
27%
1300
February16th to endNight
27%
631
24%
1893
9%
631
38%
631
24%
1209
March1st to 15thNight
31%
617
24%
2057
13%
617
43%
617
23%
1290
March16th to endNight
44%
555
24%
1969
18%
555
53%
555
30%
1059
April1st to 15thNight
40%
494
25%
1647
18%
494
50%
494
26%
980
April16th to endNight
49%
495
26%
1650
22%
495
61%
495
36%
878
May1st to 15thNight
54%
494
22%
1649
18%
494
63%
494
32%
928
May16th to endNight
69%
515
21%
1709
22%
513
73%
513
36%
941
June1st to 15thNight
79%
495
16%
1490
17%
495
80%
495
37%
865
June16th to endNight
76%
495
16%
1485
17%
495
77%
495
32%
911
July1st to 15thNight
81%
465
15%
1395
16%
465
81%
465
31%
866
July16th to endNight
74%
522
11%
1576
13%
489
75%
489
23%
1040
August1st to 15thNight
80%
494
12%
1638
15%
491
80%
491
31%
971
August16th to endNight
75%
525
14%
1750
17%
525
75%
525
26%
1116
September1st to 15thNight
72%
495
20%
1650
23%
495
73%
495
28%
1014
September16th to endNight
68%
624
27%
1782
23%
624
70%
624
33%
1091
October1st to 15thNight
63%
660
33%
1917
26%
660
68%
660
44%
1035
October16th to endNight
56%
704
35%
2112
28%
704
63%
704
40%
1134
November1st to 15thNight
52%
700
33%
2106
25%
700
61%
700
37%
1173
November16th to endNight
45%
720
31%
2340
24%
720
56%
720
34%
1283
December1st to 15thNight
37%
720
24%
2340
17%
720
47%
720
25%
1439
December16th to endNight
32%
819
19%
2415
11%
819
39%
819
20%
1670

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
12%6%25%6%35%5%5%7%37%
45466
Night
11%42442445%8%46%
45602
TransparencyDay
43%5%10%17%16%6%
45180
Night
35%5%12%19%18%8%
45394
SeeingDay
13%413%25%27%15%
4599
Night
13%6%20%29%23%6%
14690

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 15thDay
16%5%25%324446%43%
1611
16th to endDay
20%6%2432333345%
1837
February1st to 15thDay
14%7%25%413436%44%
1750
16th to endDay
17%6%25%424347%40%
1580
March1st to 15thDay
19%6%25%423445%41%
1913
16th to endDay
11%6%25%5%35%5%6%6%41%
2095
April1st to 15thDay
15%7%245%35%46%7%37%
1971
16th to endDay
11%5%25%5%35%5%5%7%40%
1980
May1st to 15thDay
12%6%36%6%35%5%5%8%35%
1971
16th to endDay
9%5%36%6%45%7%6%7%35%
2052
June1st to 15thDay
6%5%28%8%48%7%8%10%28%
2098
16th to endDay
5%6%36%8%6%9%9%8%10%26%
2145
July1st to 15thDay
10%7%37%9%5%8%8%7%8%23%
2145
16th to endDay
10%7%46%9%5%8%7%8%10%20%
2163
August1st to 15thDay
8%6%27%7%46%8%7%10%29%
1980
16th to endDay
12%6%38%8%46%6%6%8%27%
2100
September1st to 15thDay
13%6%26%7%47%6%5%6%31%
1980
16th to endDay
9%6%35%6%45%5%5%5%41%
1837
October1st to 15thDay
7%4245%2345%5%53%
1710
16th to endDay
8%3135%23445%56%
1760
November1st to 15thDay
10%6%14423445%51%
1749
16th to endDay
11%5%1432225%5%54%
1620
December1st to 15thDay
16%7%35%43444441%
1620
16th to endDay
20%8%345%3435%6%34%
1799
January1st to 15thNight
17%5%24322446%46%
2327
16th to endNight
19%6%24323345%43%
2382
February1st to 15thNight
15%6%2432335%6%45%
2103
16th to endNight
19%6%24322336%44%
1893
March1st to 15thNight
15%5%245%24436%42%
2057
16th to endNight
12%423223246%54%
1969
April1st to 15thNight
12%5%23435%35%8%44%
1647
16th to endNight
9%31432335%7%54%
1650
May1st to 15thNight
8%31443446%9%47%
1649
16th to endNight
6%4143336%6%9%50%
1709
June1st to 15thNight
3325%5%346%8%14%43%
1490
16th to endNight
42245%36%7%7%10%43%
1485
July1st to 15thNight
43235%37%5%8%14%39%
1485
16th to endNight
5%326%6%47%6%9%12%34%
1694
August1st to 15thNight
4215%5%45%8%7%13%41%
1650
16th to endNight
7%5%25%436%6%7%12%37%
1750
September1st to 15thNight
9%5%34435%5%7%9%41%
1650
16th to endNight
7%426%435%5%6%8%45%
1782
October1st to 15thNight
6%314312347%60%
1917
16th to endNight
10%32331324460%
2112
November1st to 15thNight
11%32242335%5%54%
2106
16th to endNight
12%5%2432224455%
2340
December1st to 15thNight
14%6%25%324447%43%
2340
16th to endNight
20%8%36%5%34336%35%
2415

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
42%3415%23%11%
1612
16th to endDay
43%2415%23%10%
1837
February1st to 15thDay
40%46%16%21%10%
1752
16th to endDay
44%35%16%21%8%
1580
March1st to 15thDay
45%26%19%19%6%
1913
16th to endDay
41%39%17%21%6%
2097
April1st to 15thDay
44%48%17%16%8%
1971
16th to endDay
40%49%22%18%4
1980
May1st to 15thDay
44%411%18%14%6%
1971
16th to endDay
43%6%11%21%16%1
2056
June1st to 15thDay
48%6%13%20%9%1
2098
16th to endDay
46%10%15%20%7%
2145
July1st to 15thDay
53%8%16%14%5%1
2006
16th to endDay
54%10%16%14%3
2019
August1st to 15thDay
46%9%20%14%8%
1968
16th to endDay
51%8%15%13%8%2
2100
September1st to 15thDay
48%7%13%17%10%2
1980
16th to endDay
41%6%8%17%19%7%
1837
October1st to 15thDay
32%37%17%23%15%
1710
16th to endDay
29%3414%29%19%
1760
November1st to 15thDay
33%35%17%31%9%
1749
16th to endDay
32%25%15%27%16%
1620
December1st to 15thDay
44%37%18%18%7%
1620
16th to endDay
50%27%17%17%4
1799
January1st to 15thNight
38%36%17%23%10%
2327
16th to endNight
43%35%14%23%10%
2382
February1st to 15thNight
39%26%18%21%12%
2112
16th to endNight
42%35%16%20%11%
1893
March1st to 15thNight
42%37%16%22%6%
2057
16th to endNight
31%411%21%24%7%
1969
April1st to 15thNight
38%310%22%16%9%
1647
16th to endNight
29%412%23%22%8%
1650
May1st to 15thNight
31%5%14%25%16%5%
1650
16th to endNight
28%6%17%27%17%2
1711
June1st to 15thNight
27%8%20%30%12%
1490
16th to endNight
32%8%22%23%12%
1485
July1st to 15thNight
28%13%28%19%7%1
1395
16th to endNight
36%13%26%19%2
1576
August1st to 15thNight
28%11%30%19%8%1
1638
16th to endNight
36%10%25%15%8%3
1750
September1st to 15thNight
35%7%21%18%11%5%
1650
16th to endNight
34%6%13%19%16%9%
1782
October1st to 15thNight
25%38%19%25%17%
1917
16th to endNight
27%2415%27%21%
2112
November1st to 15thNight
30%37%16%29%12%
2106
16th to endNight
32%25%17%21%19%
2340
December1st to 15thNight
40%38%21%18%6%
2340
16th to endNight
51%26%15%16%7%
2415

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
27%12%26%21%10%2
90
16th to endDay
28%19%41%6%4
96
February1st to 15thDay
20%15%37%22%4
90
16th to endDay
18%17%37%22%4
81
March1st to 15thDay
30%12%41%15%1
90
16th to endDay
19%9%25%27%15%2
139
April1st to 15thDay
26%7%22%26%15%1
210
16th to endDay
16%5%18%33%22%3
210
May1st to 15thDay
16%417%37%19%4
228
16th to endDay
12%113%25%31%16%
267
June1st to 15thDay
8%26%29%37%15%
312
16th to endDay
317%30%34%22%
420
July1st to 15thDay
10%1425%38%20%
400
16th to endDay
10%217%36%32%
324
August1st to 15thDay
9%113%35%38%
253
16th to endDay
9%320%32%32%
268
September1st to 15thDay
12%2418%39%22%
255
16th to endDay
10%1429%39%12%
254
October1st to 15thDay
8%416%30%30%10%
150
16th to endDay
14%416%36%20%7%
96
November1st to 15thDay
24%130%33%8%2
90
16th to endDay
13%14%33%24%11%3
90
December1st to 15thDay
23%10%37%22%42
90
16th to endDay
29%14%22%26%6%1
96
January1st to 15thNight
19%11%29%29%8%
900
16th to endNight
23%11%31%28%5%
846
February1st to 15thNight
18%12%32%28%8%
704
16th to endNight
22%13%31%28%3
631
March1st to 15thNight
18%11%32%29%7%
617
16th to endNight
15%9%26%32%15%
555
April1st to 15thNight
15%9%28%31%15%
494
16th to endNight
12%330%38%14%
495
May1st to 15thNight
10%225%39%20%
495
16th to endNight
6%113%40%29%7%
515
June1st to 15thNight
4436%46%8%
495
16th to endNight
415%25%43%19%
495
July1st to 15thNight
41221%49%20%
465
16th to endNight
6%1115%47%27%
522
August1st to 15thNight
5%17%45%30%
494
16th to endNight
8%1217%43%26%
525
September1st to 15thNight
11%2422%40%20%
495
16th to endNight
11%5%30%42%9%
624
October1st to 15thNight
8%217%33%33%4
660
16th to endNight
13%421%31%24%4
704
November1st to 15thNight
13%5%22%36%20%2
700
16th to endNight
13%8%27%32%17%
720
December1st to 15thNight
17%10%29%28%13%
720
16th to endNight
25%9%26%28%9%
819
Page generated at 2017-03-25 11:39:52. Version ac04

Copyright 2017 A. Danko


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