Indian Springs
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Indian Springs 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
74%
15840
36%
47193
30%
15804
80%
15804
59%
21286

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
71%
716
31%
2327
29%
716
78%
716
52%
1045
January16th to endNight
68%
768
34%
2454
31%
768
75%
768
47%
1190
February1st to 15thNight
70%
697
32%
2112
28%
697
78%
697
51%
1037
February16th to endNight
62%
632
33%
1895
32%
632
69%
632
49%
948
March1st to 15thNight
68%
720
32%
2121
27%
720
78%
720
58%
972
March16th to endNight
66%
768
34%
2100
25%
768
73%
768
57%
1032
April1st to 15thNight
59%
719
34%
1799
15%
719
69%
719
61%
898
April16th to endNight
62%
642
39%
1722
20%
642
72%
642
66%
779
May1st to 15thNight
70%
539
34%
1619
23%
539
75%
539
61%
696
May16th to endNight
68%
561
34%
1685
25%
561
74%
561
63%
719
June1st to 15thNight
75%
540
31%
1620
26%
540
79%
540
70%
659
June16th to endNight
86%
387
40%
1467
45%
387
91%
387
81%
442
July1st to 15thNight
87%
398
31%
1418
33%
398
88%
398
58%
570
July16th to endNight
89%
564
32%
1593
29%
531
89%
531
57%
753
August1st to 15thNight
88%
593
38%
1665
28%
590
89%
590
70%
728
August16th to endNight
88%
764
42%
1910
28%
764
89%
764
71%
917
September1st to 15thNight
88%
720
37%
1899
29%
720
91%
720
68%
883
September16th to endNight
84%
716
49%
1980
41%
716
90%
716
84%
789
October1st to 15thNight
79%
720
39%
1980
34%
720
84%
720
66%
901
October16th to endNight
80%
768
43%
2376
41%
768
87%
768
65%
988
November1st to 15thNight
78%
700
37%
2275
36%
700
86%
700
62%
937
November16th to endNight
78%
720
39%
2340
38%
720
84%
720
61%
974
December1st to 15thNight
70%
720
32%
2340
29%
720
78%
720
47%
1131
December16th to endNight
62%
768
30%
2496
26%
768
70%
768
40%
1298

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
111212346%73%
48548
Night
111212346%74%
47383
TransparencyDay
13%47%17%27%30%
48238
Night
12%48%18%27%28%
47194
SeeingDay
39%23%35%22%7%
5842
Night
1316%37%32%7%
15854

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
12313246%71%
1611
16th to endDay
12232325%6%67%
1768
February1st to 15thDay
111121345%9%66%
1751
16th to endDay
2212223447%67%
1579
March1st to 15thDay
11111235%8%71%
1837
16th to endDay
11222435%8%67%
2121
April1st to 15thDay
1112223436%70%
2149
16th to endDay
111112235%77%
2238
May1st to 15thDay
2112346%75%
2331
16th to endDay
111212346%73%
2429
June1st to 15thDay
11235%81%
2340
16th to endDay
112486%
2487
July1st to 15thDay
112224446%68%
2451
16th to endDay
11133345%6%8%60%
2467
August1st to 15thDay
112112345%74%
2283
16th to endDay
1121235%5%73%
2292
September1st to 15thDay
112223345%72%
2059
16th to endDay
1123483%
1980
October1st to 15thDay
111213236%76%
1980
16th to endDay
1211223479%
1843
November1st to 15thDay
11212347%74%
1584
16th to endDay
1212337%74%
1620
December1st to 15thDay
112423345%67%
1620
16th to endDay
121222336%9%65%
1728
January1st to 15thNight
11221335%7%70%
2327
16th to endNight
13332335%7%65%
2454
February1st to 15thNight
132323347%67%
2101
16th to endNight
1312324336%67%
1895
March1st to 15thNight
1121335%8%71%
2121
16th to endNight
1112112247%71%
2100
April1st to 15thNight
1111112248%73%
1799
16th to endNight
11112236%77%
1722
May1st to 15thNight
11212346%74%
1619
16th to endNight
11112236%78%
1684
June1st to 15thNight
111222383%
1620
16th to endNight
112388%
1467
July1st to 15thNight
1111213346%72%
1503
16th to endNight
111122445%7%68%
1701
August1st to 15thNight
1111222479%
1674
16th to endNight
11212235%79%
1910
September1st to 15thNight
11112346%76%
1899
16th to endNight
112387%
1980
October1st to 15thNight
1112436%76%
1980
16th to endNight
1112335%79%
2376
November1st to 15thNight
12111246%77%
2275
16th to endNight
11122245%77%
2340
December1st to 15thNight
133223447%65%
2340
16th to endNight
111442445%7%62%
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
13%5%13%28%30%8%
1612
16th to endDay
17%5%11%27%27%10%
1768
February1st to 15thDay
15%5%14%23%25%14%
1751
16th to endDay
17%6%11%20%30%13%
1579
March1st to 15thDay
12%39%24%35%14%
1837
16th to endDay
15%5%12%23%29%14%
2121
April1st to 15thDay
16%48%19%30%20%
2149
16th to endDay
10%26%22%33%23%
2238
May1st to 15thDay
10%36%17%33%28%
2331
16th to endDay
13%35%13%33%29%
2432
June1st to 15thDay
7%248%22%53%
2340
16th to endDay
5%125%14%70%
2487
July1st to 15thDay
15%35%10%17%47%
2307
16th to endDay
19%49%12%18%35%
2312
August1st to 15thDay
11%35%11%17%51%
2268
16th to endDay
12%35%11%19%47%
2292
September1st to 15thDay
14%35%9%19%47%
2059
16th to endDay
6%2311%31%45%
1980
October1st to 15thDay
12%4414%30%33%
1980
16th to endDay
10%25%16%34%30%
1843
November1st to 15thDay
11%47%21%37%18%
1584
16th to endDay
11%48%23%36%15%
1620
December1st to 15thDay
19%6%13%24%29%6%
1620
16th to endDay
17%10%14%28%20%9%
1728
January1st to 15thNight
14%6%11%26%32%8%
2327
16th to endNight
18%6%11%23%24%15%
2454
February1st to 15thNight
18%5%12%22%25%16%
2112
16th to endNight
20%410%21%31%11%
1895
March1st to 15thNight
12%411%23%32%14%
2121
16th to endNight
13%5%11%24%28%15%
2100
April1st to 15thNight
11%49%23%32%18%
1799
16th to endNight
10%25%21%34%25%
1722
May1st to 15thNight
11%35%18%32%29%
1620
16th to endNight
10%36%13%35%31%
1685
June1st to 15thNight
8%248%21%54%
1620
16th to endNight
3116%15%71%
1467
July1st to 15thNight
13%35%8%17%52%
1418
16th to endNight
15%5%6%14%18%40%
1593
August1st to 15thNight
10%2411%18%53%
1665
16th to endNight
10%2410%23%48%
1910
September1st to 15thNight
9%47%11%17%49%
1899
16th to endNight
4211%32%48%
1980
October1st to 15thNight
9%5%5%14%28%36%
1980
16th to endNight
9%35%16%30%34%
2376
November1st to 15thNight
10%47%20%36%19%
2275
16th to endNight
11%48%19%32%23%
2340
December1st to 15thNight
18%6%12%25%28%8%
2340
16th to endNight
21%8%14%24%23%7%
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
46%25%48%11%3
90
16th to endDay
29%19%38%20%8%
136
February1st to 15thDay
313%22%36%18%5%
266
16th to endDay
5%20%30%27%13%4
238
March1st to 15thDay
317%24%26%23%4
270
16th to endDay
6%15%32%28%14%2
288
April1st to 15thDay
7%20%28%20%16%5%
269
16th to endDay
7%23%28%25%11%3
270
May1st to 15thDay
312%32%27%19%4
288
16th to endDay
313%23%33%20%4
330
June1st to 15thDay
36%30%36%19%5%
315
16th to endDay
5%21%33%27%11%
315
July1st to 15thDay
2115%43%27%9%
305
16th to endDay
213%45%28%9%
327
August1st to 15thDay
1220%42%24%7%
315
16th to endDay
2114%38%29%13%
332
September1st to 15thDay
2318%42%25%7%
315
16th to endDay
26%19%32%31%7%
315
October1st to 15thDay
19%30%38%14%5%
315
16th to endDay
25%16%29%30%15%
177
November1st to 15thDay
4311%28%34%17%
90
16th to endDay
25%21%46%24%
90
December1st to 15thDay
222%48%24%2
90
16th to endDay
8%417%42%21%5%
96
January1st to 15thNight
2318%41%26%7%
720
16th to endNight
3218%43%25%6%
768
February1st to 15thNight
3119%46%23%5%
704
16th to endNight
35%25%40%20%4
632
March1st to 15thNight
15%22%41%24%4
720
16th to endNight
27%21%39%23%5%
768
April1st to 15thNight
19%26%33%24%5%
719
16th to endNight
7%26%34%24%5%
642
May1st to 15thNight
15%19%42%27%3
540
16th to endNight
26%20%31%34%4
563
June1st to 15thNight
1317%42%30%4
540
16th to endNight
19%40%39%7%
387
July1st to 15thNight
26%30%51%9%
398
16th to endNight
2332%54%6%
564
August1st to 15thNight
16%39%47%5%
593
16th to endNight
15%28%46%16%
764
September1st to 15thNight
15%30%45%15%
720
16th to endNight
112%29%43%13%
716
October1st to 15thNight
1314%41%32%7%
720
16th to endNight
1213%33%38%11%
768
November1st to 15thNight
216%35%36%9%
700
16th to endNight
1115%41%31%7%
720
December1st to 15thNight
3417%41%28%4
720
16th to endNight
2325%39%24%4
768
Page generated at 2017-11-01 14:23:36. Version ac04

Copyright 2017 A. Danko


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