Salome Observing Station
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Salome Observing Station clear sky chart from 2005-11-05 to 2018-02-13.

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
77%
16469
39%
48780
33%
16429
82%
16429
61%
21843

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
74%
780
34%
2522
34%
776
80%
776
49%
1186
January16th to endNight
69%
832
40%
2668
38%
832
77%
832
49%
1264
February1st to 15thNight
74%
747
40%
2255
36%
747
82%
747
58%
1009
February16th to endNight
65%
632
36%
1895
37%
632
71%
632
49%
940
March1st to 15thNight
69%
720
39%
2052
33%
720
79%
720
61%
937
March16th to endNight
69%
768
38%
2112
30%
768
77%
768
60%
1008
April1st to 15thNight
62%
719
35%
1916
19%
719
70%
719
60%
923
April16th to endNight
67%
615
46%
1695
26%
615
80%
615
78%
698
May1st to 15thNight
72%
539
40%
1619
28%
539
80%
539
68%
663
May16th to endNight
77%
561
40%
1684
29%
561
83%
561
75%
666
June1st to 15thNight
84%
540
36%
1620
31%
540
85%
540
75%
632
June16th to endNight
91%
540
38%
1620
33%
540
92%
540
83%
601
July1st to 15thNight
90%
510
30%
1530
26%
510
91%
510
59%
699
July16th to endNight
84%
564
31%
1593
25%
531
85%
531
50%
782
August1st to 15thNight
89%
562
37%
1634
30%
559
90%
559
62%
746
August16th to endNight
86%
764
40%
1910
30%
764
86%
764
63%
965
September1st to 15thNight
85%
720
35%
1977
31%
720
86%
720
63%
942
September16th to endNight
86%
716
47%
1980
40%
716
91%
716
78%
830
October1st to 15thNight
79%
720
43%
1983
36%
720
84%
720
70%
880
October16th to endNight
85%
768
47%
2304
44%
768
90%
768
71%
939
November1st to 15thNight
79%
760
39%
2437
37%
760
85%
760
60%
1046
November16th to endNight
77%
780
43%
2535
44%
780
84%
780
60%
1076
December1st to 15thNight
74%
780
38%
2535
37%
780
80%
780
53%
1137
December16th to endNight
67%
832
39%
2704
37%
832
75%
832
48%
1274

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
212212335%72%
49258
Night
2112212335%72%
48977
TransparencyDay
14%2411%24%43%
48953
Night
14%2411%24%43%
48783
SeeingDay
3416%34%31%10%
6124
Night
2212%35%38%7%
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
2313412236%67%
1746
16th to endDay
423212346%66%
1905
February1st to 15thDay
2112312347%68%
1872
16th to endDay
3213323347%63%
1579
March1st to 15thDay
212212247%71%
1907
16th to endDay
1212212235%73%
2112
April1st to 15thDay
121212446%71%
2029
16th to endDay
111135%83%
2264
May1st to 15thDay
1111222480%
2331
16th to endDay
11111112384%
2429
June1st to 15thDay
111111385%
2340
16th to endDay
11112286%
2340
July1st to 15thDay
1112313446%69%
2340
16th to endDay
4213435%5%6%8%54%
2467
August1st to 15thDay
222424447%63%
2314
16th to endDay
3223135%46%66%
2292
September1st to 15thDay
3213323345%66%
1983
16th to endDay
11111122482%
1980
October1st to 15thDay
1211223479%
1977
16th to endDay
1121123480%
1920
November1st to 15thDay
22213245%74%
1749
16th to endDay
222212235%74%
1755
December1st to 15thDay
2212423347%64%
1755
16th to endDay
321331335%6%64%
1872
January1st to 15thNight
3213323445%65%
2522
16th to endNight
4313313235%67%
2668
February1st to 15thNight
1312212236%71%
2245
16th to endNight
5%213323446%63%
1895
March1st to 15thNight
211212346%71%
2052
16th to endNight
1112323335%71%
2112
April1st to 15thNight
111231223473%
1916
16th to endNight
11212484%
1695
May1st to 15thNight
1211235%79%
1619
16th to endNight
111112284%
1684
June1st to 15thNight
111112483%
1620
16th to endNight
112485%
1620
July1st to 15thNight
11231345%6%69%
1620
16th to endNight
22134245%7%8%57%
1701
August1st to 15thNight
211213347%71%
1643
16th to endNight
212322347%68%
1910
September1st to 15thNight
11231345%6%70%
1977
16th to endNight
1111122384%
1980
October1st to 15thNight
11111223478%
1983
16th to endNight
1111225%79%
2304
November1st to 15thNight
1113212235%73%
2437
16th to endNight
221221213475%
2535
December1st to 15thNight
2213323346%66%
2535
16th to endNight
3213323245%65%
2704

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
20%2413%34%25%
1747
16th to endDay
18%26%15%28%28%
1905
February1st to 15thDay
15%2413%28%34%
1872
16th to endDay
20%25%14%30%26%
1579
March1st to 15thDay
14%1310%30%40%
1907
16th to endDay
14%1311%31%37%
2112
April1st to 15thDay
12%2310%30%40%
2029
16th to endDay
6%119%29%51%
2264
May1st to 15thDay
10%118%25%52%
2331
16th to endDay
8%26%22%59%
2432
June1st to 15thDay
7%1415%70%
2340
16th to endDay
6%136%79%
2340
July1st to 15thDay
14%46%11%16%46%
2201
16th to endDay
24%6%9%20%18%21%
2312
August1st to 15thDay
18%46%15%21%33%
2299
16th to endDay
16%36%12%27%33%
2292
September1st to 15thDay
20%26%12%21%36%
1983
16th to endDay
8%125%19%63%
1980
October1st to 15thDay
10%129%24%52%
1977
16th to endDay
9%148%20%55%
1920
November1st to 15thDay
12%1215%28%38%
1749
16th to endDay
13%1311%30%39%
1755
December1st to 15thDay
19%25%16%25%29%
1755
16th to endDay
19%36%19%31%19%
1872
January1st to 15thNight
19%3412%27%32%
2522
16th to endNight
21%2314%25%33%
2668
February1st to 15thNight
15%2414%25%37%
2256
16th to endNight
22%2412%25%32%
1895
March1st to 15thNight
13%2310%26%42%
2052
16th to endNight
16%2410%29%37%
2112
April1st to 15thNight
15%239%29%40%
1916
16th to endNight
5%129%26%54%
1695
May1st to 15thNight
9%126%25%53%
1620
16th to endNight
8%16%24%57%
1685
June1st to 15thNight
8%11415%69%
1620
16th to endNight
5%138%80%
1620
July1st to 15thNight
15%26%11%16%46%
1530
16th to endNight
19%411%22%18%24%
1593
August1st to 15thNight
13%3313%28%37%
1634
16th to endNight
15%37%11%27%35%
1910
September1st to 15thNight
13%36%14%24%37%
1977
16th to endNight
7%125%18%64%
1980
October1st to 15thNight
10%238%21%53%
1983
16th to endNight
9%138%17%58%
2304
November1st to 15thNight
15%1210%26%43%
2437
16th to endNight
15%1210%27%43%
2535
December1st to 15thNight
18%25%13%26%33%
2535
16th to endNight
20%25%17%27%25%
2704

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
9%220%37%25%5%
135
16th to endDay
25%20%27%34%10%
177
February1st to 15thDay
46%21%29%28%9%
315
16th to endDay
8%10%25%34%18%2
238
March1st to 15thDay
312%18%33%25%6%
270
16th to endDay
212%24%32%21%6%
288
April1st to 15thDay
410%24%34%17%8%
269
16th to endDay
112%34%28%17%4
270
May1st to 15thDay
35%23%37%21%7%
288
16th to endDay
2323%38%24%7%
330
June1st to 15thDay
2118%41%29%6%
315
16th to endDay
19%40%33%13%
315
July1st to 15thDay
6%40%39%12%
305
16th to endDay
3330%42%20%
327
August1st to 15thDay
25%35%42%13%
315
16th to endDay
4131%46%15%
332
September1st to 15thDay
3110%38%33%12%
315
16th to endDay
2116%36%32%9%
315
October1st to 15thDay
5%20%36%30%6%
312
16th to endDay
22425%45%18%
144
November1st to 15thDay
229%34%42%8%
135
16th to endDay
5%223%28%29%10%
135
December1st to 15thDay
1217%31%40%6%
135
16th to endDay
4413%34%31%10%
144
January1st to 15thNight
5%112%38%32%9%
780
16th to endNight
6%214%38%32%5%
832
February1st to 15thNight
3314%37%35%6%
752
16th to endNight
5%319%41%23%6%
632
March1st to 15thNight
3419%35%30%6%
720
16th to endNight
15%18%36%30%7%
768
April1st to 15thNight
2425%35%26%5%
719
16th to endNight
1424%38%25%5%
615
May1st to 15thNight
1419%38%31%4
540
16th to endNight
217%43%31%4
563
June1st to 15thNight
110%47%35%3
540
16th to endNight
5%39%49%5%
540
July1st to 15thNight
2232%56%6%
510
16th to endNight
1325%59%8%
564
August1st to 15thNight
3223%61%9%
562
16th to endNight
3223%55%14%
764
September1st to 15thNight
25%26%52%12%
720
16th to endNight
19%29%47%11%
716
October1st to 15thNight
1113%36%40%5%
720
16th to endNight
18%33%42%13%
768
November1st to 15thNight
111%40%35%9%
760
16th to endNight
3112%31%38%12%
780
December1st to 15thNight
4113%40%34%5%
780
16th to endNight
5%315%37%31%6%
832
Page generated at 2018-02-13 18:46:03. Version ac04

Copyright 2018 A. Danko


Salome Observing Station Clear Sky Chart |Charts Home