Warm Springs Ranch
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Warm Springs Ranch clear sky chart from 2005-11-05 to 2018-01-20.

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
40%
16469
27%
48496
12%
16425
55%
16425
39%
25143

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
26%
952
31%
2696
9%
950
47%
950
44%
1240
January16th to endNight
25%
788
35%
2561
13%
788
52%
788
44%
1122
February1st to 15thNight
22%
700
26%
2274
6%
696
45%
696
35%
1108
February16th to endNight
24%
632
33%
1894
8%
632
50%
632
41%
926
March1st to 15thNight
30%
720
29%
2067
10%
720
47%
720
41%
1056
March16th to endNight
28%
708
27%
2052
8%
708
45%
708
38%
1084
April1st to 15thNight
33%
539
25%
1798
9%
539
53%
539
35%
869
April16th to endNight
30%
540
23%
1800
11%
540
48%
540
28%
992
May1st to 15thNight
38%
539
19%
1629
9%
539
50%
539
28%
967
May16th to endNight
47%
563
19%
1498
10%
561
55%
561
35%
883
June1st to 15thNight
54%
540
25%
1440
14%
540
61%
540
51%
737
June16th to endNight
66%
540
26%
1440
20%
540
71%
540
54%
738
July1st to 15thNight
70%
510
16%
1360
15%
510
72%
510
31%
864
July16th to endNight
71%
564
16%
1509
16%
531
72%
531
30%
942
August1st to 15thNight
71%
539
16%
1644
15%
536
73%
536
31%
971
August16th to endNight
68%
573
22%
1910
23%
573
71%
573
29%
1118
September1st to 15thNight
67%
540
26%
1800
22%
540
74%
540
33%
1004
September16th to endNight
59%
570
32%
1938
24%
570
71%
570
42%
961
October1st to 15thNight
41%
720
31%
2160
13%
720
56%
720
46%
1069
October16th to endNight
44%
768
36%
2304
16%
768
60%
768
48%
1110
November1st to 15thNight
36%
934
33%
2454
12%
934
49%
934
51%
1213
November16th to endNight
33%
975
36%
2626
13%
975
50%
975
48%
1266
December1st to 15thNight
22%
975
24%
2730
4%
975
40%
975
38%
1356
December16th to endNight
24%
1040
27%
2912
8%
1040
42%
1040
34%
1547

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
3425%5%35%5%5%8%50%
49037
Night
231332335%8%62%
48676
TransparencyDay
29%8%14%23%18%5%
48719
Night
20%6%17%29%20%5%
48496
SeeingDay
8%21%30%23%12%3
6180
Night
315%35%28%15%1
16477

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
2132245%5%9%63%
1584
16th to endDay
22432446%8%61%
1766
February1st to 15thDay
3244245%5%9%57%
1588
16th to endDay
115%5%36%5%5%8%56%
1580
March1st to 15thDay
425%5%2445%7%56%
1890
16th to endDay
1434435%47%9%50%
2172
April1st to 15thDay
2425%5%35%45%10%50%
2150
16th to endDay
39%35%6%45%5%5%8%42%
2160
May1st to 15thDay
6%8%36%5%36%5%6%7%38%
2316
16th to endDay
5%6%35%6%36%6%7%7%41%
2616
June1st to 15thDay
44245%35%5%5%8%49%
2520
16th to endDay
2314436%6%6%7%53%
2520
July1st to 15thDay
8%6%36%6%46%5%6%7%37%
2520
16th to endDay
9%7%36%6%47%7%6%8%32%
2552
August1st to 15thDay
10%6%38%7%46%5%5%7%33%
2307
16th to endDay
7%5%37%5%46%6%6%8%38%
2292
September1st to 15thDay
7%5%25%5%25%45%6%48%
2160
16th to endDay
34245%33445%58%
2018
October1st to 15thDay
331343435%7%58%
1800
16th to endDay
22233135%46%63%
1920
November1st to 15thDay
2221335%7%70%
1721
16th to endDay
212213248%70%
1661
December1st to 15thDay
22342335%6%65%
1560
16th to endDay
21432346%11%58%
1664
January1st to 15thNight
111212348%71%
2696
16th to endNight
113212236%74%
2561
February1st to 15thNight
21422335%7%66%
2263
16th to endNight
21231235%8%66%
1894
March1st to 15thNight
313213348%66%
2067
16th to endNight
1423223347%62%
2052
April1st to 15thNight
41221345%8%63%
1798
16th to endNight
47%343135%35%57%
1800
May1st to 15thNight
6%8%3422346%8%48%
1628
16th to endNight
5%5%2342346%9%52%
1497
June1st to 15thNight
221221235%10%65%
1440
16th to endNight
2112315%46%8%63%
1440
July1st to 15thNight
5%4145%25%6%7%10%46%
1440
16th to endNight
5%4245%26%6%7%9%45%
1613
August1st to 15thNight
6%4144245%7%9%48%
1653
16th to endNight
5%4145%346%6%8%48%
1910
September1st to 15thNight
6%3243335%6%7%53%
1800
16th to endNight
4313322346%63%
1938
October1st to 15thNight
3212323347%67%
2160
16th to endNight
1222212346%67%
2304
November1st to 15thNight
11212347%72%
2454
16th to endNight
21211325%8%70%
2626
December1st to 15thNight
212313237%69%
2730
16th to endNight
214312449%64%
2912

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
17%7%26%28%16%3
1585
16th to endDay
19%7%19%31%18%5%
1766
February1st to 15thDay
22%10%20%30%12%3
1588
16th to endDay
23%8%15%28%19%4
1580
March1st to 15thDay
25%7%16%29%18%2
1890
16th to endDay
28%7%17%28%14%4
2172
April1st to 15thDay
29%9%16%25%15%4
2150
16th to endDay
38%7%13%23%13%2
2160
May1st to 15thDay
41%9%12%21%12%
2316
16th to endDay
38%9%13%21%13%3
2620
June1st to 15thDay
29%8%11%17%22%10%
2520
16th to endDay
26%7%8%21%25%10%
2520
July1st to 15thDay
42%11%11%14%13%7%
2371
16th to endDay
44%13%14%15%8%3
2393
August1st to 15thDay
47%10%11%11%12%5%
2292
16th to endDay
38%12%12%19%14%3
2292
September1st to 15thDay
34%8%12%15%20%9%
2160
16th to endDay
27%5%10%25%26%4
2018
October1st to 15thDay
23%7%10%24%27%7%
1800
16th to endDay
21%5%10%30%27%5%
1920
November1st to 15thDay
13%6%15%26%28%9%
1721
16th to endDay
14%414%34%24%7%
1661
December1st to 15thDay
19%7%21%32%16%3
1560
16th to endDay
19%10%21%27%16%4
1664
January1st to 15thNight
12%425%34%19%4
2696
16th to endNight
13%5%18%33%22%6%
2561
February1st to 15thNight
19%5%19%36%16%3
2274
16th to endNight
16%5%16%35%21%4
1894
March1st to 15thNight
17%6%15%34%21%3
2067
16th to endNight
21%5%17%34%17%3
2052
April1st to 15thNight
18%7%17%33%19%4
1798
16th to endNight
29%6%15%31%15%2
1800
May1st to 15thNight
32%7%16%27%13%1
1629
16th to endNight
27%7%18%27%15%3
1498
June1st to 15thNight
15%7%16%25%24%11%
1440
16th to endNight
16%6%13%23%27%12%
1440
July1st to 15thNight
30%12%16%18%14%7%
1360
16th to endNight
31%12%22%19%10%3
1509
August1st to 15thNight
28%11%20%18%14%6%
1644
16th to endNight
29%11%16%21%17%3
1910
September1st to 15thNight
28%9%15%22%17%8%
1800
16th to endNight
22%5%13%30%24%3
1938
October1st to 15thNight
17%6%12%29%26%8%
2160
16th to endNight
17%412%30%29%5%
2304
November1st to 15thNight
12%5%14%28%29%9%
2454
16th to endNight
13%414%36%25%6%
2626
December1st to 15thNight
16%5%24%29%20%2
2730
16th to endNight
18%8%20%29%18%3
2912

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
234%27%22%11%
135
16th to endDay
125%34%32%4
109
February1st to 15thDay
7%48%34%5%3
90
16th to endDay
45%27%17%9%
81
March1st to 15thDay
5%37%34%20%2
180
16th to endDay
8%42%34%11%2
288
April1st to 15thDay
6%37%34%15%5%
269
16th to endDay
15%40%27%12%2
270
May1st to 15thDay
9%25%35%18%8%1
366
16th to endDay
9%18%29%26%11%4
517
June1st to 15thDay
5%18%26%27%18%3
495
16th to endDay
39%28%29%23%5%
495
July1st to 15thDay
12%423%29%22%8%
475
16th to endDay
11%125%31%21%8%
411
August1st to 15thDay
16%5%31%31%12%2
315
16th to endDay
15%7%26%30%15%3
332
September1st to 15thDay
11%13%35%25%11%3
315
16th to endDay
7%21%34%22%8%5%
209
October1st to 15thDay
5%23%27%21%18%2
135
16th to endDay
7%24%23%25%16%2
144
November1st to 15thDay
230%22%23%17%2
135
16th to endDay
5%38%39%14%1
135
December1st to 15thDay
343%37%9%5%
135
16th to endDay
236%40%14%6%
144
January1st to 15thNight
127%41%21%7%1
955
16th to endNight
122%46%20%7%1
788
February1st to 15thNight
22%48%21%5%
704
16th to endNight
21%49%23%4
632
March1st to 15thNight
219%43%26%7%
720
16th to endNight
419%45%25%5%
708
April1st to 15thNight
319%42%28%6%
539
16th to endNight
9%18%37%26%7%
540
May1st to 15thNight
9%11%36%29%12%1
540
16th to endNight
8%10%28%33%17%2
563
June1st to 15thNight
36%28%39%19%1
540
16th to endNight
1323%39%30%2
540
July1st to 15thNight
7%10%34%41%4
510
16th to endNight
8%18%29%46%5%
564
August1st to 15thNight
8%10%37%39%3
539
16th to endNight
7%12%35%38%6%
573
September1st to 15thNight
8%115%39%28%6%
540
16th to endNight
5%5%25%37%22%3
570
October1st to 15thNight
49%40%27%14%2
720
16th to endNight
311%36%30%14%2
768
November1st to 15thNight
117%42%27%9%
934
16th to endNight
222%39%27%6%1
975
December1st to 15thNight
127%45%20%5%
975
16th to endNight
126%42%21%6%
1040
Page generated at 2018-01-21 10:19:31. Version ac04

Copyright 2018 A. Danko


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