Fishers
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fishers clear sky chart from 2005-11-05 to 2017-12-20.

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
39%
16192
17%
47973
12%
16149
45%
16149
23%
32348

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
16%
900
13%
2506
5%
895
24%
895
14%
1945
January16th to endNight
20%
907
11%
2635
6%
907
25%
907
14%
2046
February1st to 15thNight
21%
702
10%
2118
4%
701
27%
701
15%
1552
February16th to endNight
23%
631
15%
1893
7%
631
30%
631
16%
1389
March1st to 15thNight
26%
720
14%
2142
8%
720
31%
720
18%
1523
March16th to endNight
29%
723
15%
2067
7%
723
37%
723
19%
1486
April1st to 15thNight
31%
539
17%
1797
10%
539
42%
539
22%
1174
April16th to endNight
35%
540
20%
1689
11%
540
43%
540
24%
1099
May1st to 15thNight
33%
540
13%
1620
8%
540
39%
540
19%
1167
May16th to endNight
52%
562
17%
1648
12%
561
56%
561
27%
1078
June1st to 15thNight
59%
540
17%
1440
12%
540
62%
540
36%
895
June16th to endNight
58%
540
18%
1440
13%
540
63%
540
34%
916
July1st to 15thNight
63%
510
16%
1360
12%
510
65%
510
35%
853
July16th to endNight
73%
564
23%
1467
18%
531
76%
531
44%
831
August1st to 15thNight
70%
539
22%
1609
20%
536
72%
536
36%
933
August16th to endNight
71%
573
22%
1902
22%
573
75%
573
35%
1037
September1st to 15thNight
63%
611
26%
1871
23%
611
68%
611
34%
1091
September16th to endNight
61%
717
27%
1980
21%
717
65%
717
36%
1197
October1st to 15thNight
50%
720
26%
1980
20%
720
56%
720
35%
1218
October16th to endNight
30%
768
20%
2471
15%
768
38%
768
23%
1571
November1st to 15thNight
39%
760
24%
2471
17%
760
50%
760
26%
1502
November16th to endNight
30%
780
19%
2535
13%
780
39%
780
19%
1714
December1st to 15thNight
22%
822
11%
2577
6%
822
29%
822
14%
1937
December16th to endNight
17%
984
11%
2755
3%
984
24%
984
12%
2194

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
14%7%36%5%3445%7%36%
48866
Night
15%7%36%5%24446%39%
48147
Cloud CoverDay
14%7%36%5%3445%7%36%
48875
Night
15%7%36%5%24446%39%
48152
TransparencyDay
46%6%12%20%12%1
48558
Night
45%5%11%21%14%2
47973
SeeingDay
16%7%24%24%17%8%
6138
Night
18%8%28%28%14%1
16195

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
20%14%6%8%5%3334425%
1432
16th to endDay
13%15%8%8%6%24345%25%
1587
February1st to 15thDay
15%12%5%8%7%44445%27%
1741
16th to endDay
15%13%6%8%6%24345%28%
1580
March1st to 15thDay
20%10%48%5%23446%28%
1808
16th to endDay
18%9%5%6%42435%7%31%
2168
April1st to 15thDay
19%8%345%2435%6%36%
2151
16th to endDay
19%6%27%5%33346%37%
2269
May1st to 15thDay
21%7%36%6%34446%30%
2331
16th to endDay
12%5%346%35%6%6%7%37%
2464
June1st to 15thDay
11%415%5%35%5%6%8%42%
2520
16th to endDay
9%426%5%35%46%10%41%
2520
July1st to 15thDay
11%5%25%6%3447%10%39%
2520
16th to endDay
7%324436%6%7%11%42%
2601
August1st to 15thDay
8%425%5%346%6%9%43%
2340
16th to endDay
8%425%5%446%5%8%43%
2297
September1st to 15thDay
11%6%345%2445%8%42%
2076
16th to endDay
11%5%14423448%48%
1980
October1st to 15thDay
15%6%245%24446%42%
1980
16th to endDay
17%6%26%43335%6%39%
1752
November1st to 15thDay
13%6%25%5%33335%46%
1717
16th to endDay
19%9%46%43335%6%33%
1755
December1st to 15thDay
20%13%49%5%24345%26%
1709
16th to endDay
22%16%6%7%423346%22%
1568
January1st to 15thNight
21%11%48%5%3334427%
2506
16th to endNight
17%13%6%9%5%3433427%
2635
February1st to 15thNight
17%11%5%8%5%24345%31%
2116
16th to endNight
15%11%5%8%5%34445%30%
1893
March1st to 15thNight
17%8%37%5%24446%33%
2129
16th to endNight
16%9%37%5%24447%34%
2067
April1st to 15thNight
16%7%245%3445%6%39%
1797
16th to endNight
17%6%15%43345%6%41%
1689
May1st to 15thNight
20%7%36%6%2446%6%32%
1620
16th to endNight
12%435%5%35%46%9%40%
1646
June1st to 15thNight
8%5%25%33436%8%48%
1440
16th to endNight
7%3245%35%6%5%10%45%
1440
July1st to 15thNight
8%4245%3445%10%47%
1440
16th to endNight
5%22442345%9%55%
1567
August1st to 15thNight
6%41442446%9%50%
1620
16th to endNight
6%2145%3446%7%52%
1902
September1st to 15thNight
10%5%15%423448%50%
1871
16th to endNight
9%42342445%6%51%
1980
October1st to 15thNight
12%41443345%7%49%
1980
16th to endNight
18%6%24423336%42%
2471
November1st to 15thNight
14%6%34323446%46%
2471
16th to endNight
19%9%35%424346%36%
2535
December1st to 15thNight
20%10%6%8%6%2333428%
2577
16th to endNight
24%13%47%6%33345%23%
2755

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
19%14%6%8%5%23345%25%
1432
16th to endDay
13%15%8%8%7%34345%25%
1587
February1st to 15thDay
15%12%6%8%7%44445%27%
1741
16th to endDay
15%12%6%9%6%35%345%28%
1580
March1st to 15thDay
20%10%48%5%23446%28%
1818
16th to endDay
18%9%5%7%5%2435%7%31%
2167
April1st to 15thDay
19%8%35%5%2335%6%36%
2151
16th to endDay
19%6%26%5%24336%37%
2269
May1st to 15thDay
21%7%36%6%34446%30%
2331
16th to endDay
12%425%6%36%6%6%7%37%
2464
June1st to 15thDay
12%415%5%35%5%6%8%42%
2520
16th to endDay
9%425%5%35%46%9%41%
2520
July1st to 15thDay
11%5%25%6%345%6%10%38%
2520
16th to endDay
6%314436%6%7%11%42%
2601
August1st to 15thDay
8%425%5%35%5%6%9%43%
2340
16th to endDay
8%425%5%35%6%5%9%43%
2297
September1st to 15thDay
11%6%25%5%3445%8%42%
2076
16th to endDay
12%5%24423447%48%
1980
October1st to 15thDay
15%6%25%434446%43%
1980
16th to endDay
17%6%36%43345%6%39%
1752
November1st to 15thDay
13%6%35%5%33435%46%
1717
16th to endDay
18%9%46%43426%6%33%
1755
December1st to 15thDay
20%13%49%5%24335%25%
1709
16th to endDay
22%15%6%8%41435%5%22%
1568
January1st to 15thNight
20%11%5%8%5%34445%27%
2506
16th to endNight
17%13%6%9%5%3433427%
2635
February1st to 15thNight
17%11%5%8%5%24345%31%
2109
16th to endNight
15%11%5%8%5%24445%30%
1893
March1st to 15thNight
17%8%46%5%25%446%33%
2142
16th to endNight
16%9%37%5%34447%34%
2067
April1st to 15thNight
16%6%345%2445%6%39%
1797
16th to endNight
17%6%2442445%6%41%
1689
May1st to 15thNight
20%7%36%5%2446%6%32%
1619
16th to endNight
12%435%5%35%46%9%40%
1646
June1st to 15thNight
8%5%2433436%8%48%
1440
16th to endNight
7%3245%35%6%5%10%45%
1440
July1st to 15thNight
8%41443445%10%47%
1440
16th to endNight
5%2243235%5%9%55%
1567
August1st to 15thNight
6%3144245%6%10%50%
1620
16th to endNight
6%215%5%3446%7%52%
1902
September1st to 15thNight
10%5%15%323348%50%
1871
16th to endNight
9%42342445%7%51%
1980
October1st to 15thNight
12%42432435%7%49%
1980
16th to endNight
18%6%24424336%42%
2471
November1st to 15thNight
13%6%34323446%46%
2471
16th to endNight
18%9%35%424346%36%
2535
December1st to 15thNight
20%10%6%8%6%2333428%
2577
16th to endNight
24%13%47%6%33335%23%
2755

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
61%49%15%8%
1433
16th to endDay
60%414%15%4
1587
February1st to 15thDay
59%5%10%15%8%
1743
16th to endDay
58%411%20%5%
1580
March1st to 15thDay
57%5%12%18%6%
1818
16th to endDay
53%5%14%20%5%
2168
April1st to 15thDay
47%5%11%22%11%1
2151
16th to endDay
48%412%18%10%4
2269
May1st to 15thDay
54%6%11%18%9%
2331
16th to endDay
42%10%11%18%15%2
2468
June1st to 15thDay
37%7%12%23%16%1
2520
16th to endDay
38%7%14%21%16%3
2520
July1st to 15thDay
41%6%12%19%17%2
2371
16th to endDay
31%9%20%23%12%2
2438
August1st to 15thDay
35%7%14%24%17%1
2327
16th to endDay
35%8%11%23%14%6%
2297
September1st to 15thDay
39%6%10%20%18%4
2076
16th to endDay
35%5%9%24%23%1
1980
October1st to 15thDay
41%410%24%16%2
1980
16th to endDay
45%5%11%24%12%
1752
November1st to 15thDay
40%311%22%17%4
1717
16th to endDay
52%410%22%9%1
1755
December1st to 15thDay
61%5%10%16%6%
1709
16th to endDay
64%410%16%3
1568
January1st to 15thNight
60%48%18%8%
2506
16th to endNight
60%411%16%6%
2635
February1st to 15thNight
56%413%16%7%
2118
16th to endNight
54%5%12%18%7%
1893
March1st to 15thNight
51%5%12%19%8%2
2142
16th to endNight
50%5%12%22%7%1
2067
April1st to 15thNight
44%5%10%21%15%2
1797
16th to endNight
42%5%10%20%13%7%
1689
May1st to 15thNight
50%7%11%19%9%1
1620
16th to endNight
39%8%12%20%15%3
1648
June1st to 15thNight
32%6%11%25%21%1
1440
16th to endNight
32%9%13%22%18%4
1440
July1st to 15thNight
33%7%15%20%18%5%
1360
16th to endNight
25%6%14%32%18%2
1467
August1st to 15thNight
28%8%14%23%22%2
1609
16th to endNight
28%6%13%24%20%5%
1902
September1st to 15thNight
32%5%11%21%22%6%
1871
16th to endNight
32%5%9%23%25%3
1980
October1st to 15thNight
33%412%22%22%3
1980
16th to endNight
43%310%25%13%1
2471
November1st to 15thNight
38%49%21%20%4
2471
16th to endNight
49%310%24%11%
2535
December1st to 15thNight
59%39%17%9%
2577
16th to endNight
64%310%15%5%
2755

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
33%17%27%17%21
90
16th to endDay
20%23%34%17%3
96
February1st to 15thDay
23%23%35%17%
90
16th to endDay
17%13%46%16%6%
81
March1st to 15thDay
30%18%31%15%3
108
16th to endDay
23%13%33%18%9%2
288
April1st to 15thDay
19%15%29%22%11%1
270
16th to endDay
22%8%28%24%11%5%
270
May1st to 15thDay
27%9%31%19%8%3
288
16th to endDay
16%5%29%20%17%10%
364
June1st to 15thDay
11%324%33%20%6%
495
16th to endDay
11%7%29%28%15%7%
495
July1st to 15thDay
13%224%28%19%11%
475
16th to endDay
6%214%30%28%16%
461
August1st to 15thDay
13%111%21%31%20%
313
16th to endDay
9%213%25%31%17%
332
September1st to 15thDay
12%313%27%27%14%
315
16th to endDay
15%315%19%28%16%
314
October1st to 15thDay
16%6%21%29%20%5%
315
16th to endDay
18%10%40%23%7%
165
November1st to 15thDay
19%14%21%17%22%5%
135
16th to endDay
24%9%39%21%5%
135
December1st to 15thDay
17%24%34%17%5%1
135
16th to endDay
32%23%35%9%
108
January1st to 15thNight
26%14%36%19%3
900
16th to endNight
24%14%32%24%3
907
February1st to 15thNight
23%12%35%25%2
704
16th to endNight
22%10%37%25%3
631
March1st to 15thNight
21%13%34%25%5%
720
16th to endNight
21%9%33%27%6%1
723
April1st to 15thNight
17%12%34%25%8%
539
16th to endNight
19%6%35%27%10%1
540
May1st to 15thNight
21%6%30%29%11%
540
16th to endNight
13%223%36%21%2
563
June1st to 15thNight
10%221%45%19%
540
16th to endNight
9%124%39%23%1
540
July1st to 15thNight
10%118%36%30%2
510
16th to endNight
5%112%39%36%4
564
August1st to 15thNight
7%14%41%31%6%
539
16th to endNight
6%112%34%41%4
573
September1st to 15thNight
12%315%34%28%5%
611
16th to endNight
12%317%28%34%4
717
October1st to 15thNight
14%6%22%31%19%4
720
16th to endNight
22%8%34%23%9%
768
November1st to 15thNight
16%10%30%27%14%1
760
16th to endNight
23%13%28%25%8%
780
December1st to 15thNight
25%11%32%22%7%
822
16th to endNight
31%10%35%17%4
984
Page generated at 2017-12-21 07:04:44. Version ac04

Copyright 2017 A. Danko


Fishers Clear Sky Chart |Charts Home