Concordia
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Concordia clear sky chart from 2005-11-05 to 2017-09-20.

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
44%
15935
24%
46955
14%
15889
53%
15889
35%
27036

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
39%
900
25%
2327
11%
895
48%
895
36%
1434
January16th to endNight
38%
960
29%
2496
12%
960
48%
960
39%
1477
February1st to 15thNight
31%
846
17%
2256
6%
842
38%
842
26%
1537
February16th to endNight
32%
632
26%
1894
9%
632
46%
632
31%
1097
March1st to 15thNight
36%
597
23%
2037
16%
597
46%
597
31%
1112
March16th to endNight
29%
576
18%
2112
11%
576
39%
576
22%
1291
April1st to 15thNight
33%
539
18%
1879
12%
539
44%
539
27%
1092
April16th to endNight
32%
540
21%
1620
14%
540
44%
540
27%
1007
May1st to 15thNight
35%
540
17%
1620
13%
540
43%
540
25%
1051
May16th to endNight
44%
562
16%
1684
9%
561
51%
561
32%
1019
June1st to 15thNight
50%
540
18%
1620
9%
540
56%
540
40%
897
June16th to endNight
57%
540
22%
1620
11%
540
63%
540
52%
792
July1st to 15thNight
66%
510
17%
1530
14%
510
68%
510
42%
824
July16th to endNight
70%
564
23%
1594
22%
531
71%
531
42%
849
August1st to 15thNight
72%
539
22%
1610
24%
536
75%
536
41%
885
August16th to endNight
65%
573
27%
1738
27%
573
70%
573
42%
926
September1st to 15thNight
56%
540
24%
1974
22%
540
65%
540
35%
1008
September16th to endNight
55%
507
30%
1870
24%
507
65%
507
37%
933
October1st to 15thNight
44%
575
30%
1895
22%
575
52%
575
31%
1049
October16th to endNight
46%
720
30%
2128
16%
720
56%
720
43%
1115
November1st to 15thNight
48%
875
33%
2275
14%
875
58%
875
49%
1218
November16th to endNight
41%
900
29%
2340
12%
900
51%
900
40%
1361
December1st to 15thNight
35%
900
22%
2340
10%
900
43%
900
33%
1475
December16th to endNight
38%
960
26%
2496
11%
960
48%
960
32%
1587

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
9%5%2442445%7%49%
47886
Night
8%42432345%7%52%
47151
Cloud CoverDay
9%5%2442445%7%49%
47884
Night
8%5%2442345%7%52%
47151
TransparencyDay
34%6%13%26%16%2
47584
Night
30%5%13%27%18%4
46956
SeeingDay
12%6%27%32%17%2
5933
Night
11%7%32%36%11%
15938

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
6%5%245%25%45%7%50%
1611
16th to endDay
7%6%26%42435%6%48%
1728
February1st to 15thDay
8%9%35%4345%47%42%
1615
16th to endDay
6%7%25%5%34445%50%
1580
March1st to 15thDay
8%6%244345%5%7%48%
1923
16th to endDay
15%8%34423446%42%
2112
April1st to 15thDay
14%6%24333346%45%
2066
16th to endDay
18%6%35%4245%5%5%37%
2340
May1st to 15thDay
12%5%344345%46%44%
2331
16th to endDay
12%6%2443445%7%41%
2430
June1st to 15thDay
7%3234345%5%8%52%
2340
16th to endDay
3212425%5%6%8%56%
2340
July1st to 15thDay
6%323425%5%7%9%48%
2340
16th to endDay
6%2235%2446%9%51%
2466
August1st to 15thDay
7%3135%346%7%8%47%
2340
16th to endDay
7%41342335%7%55%
2462
September1st to 15thDay
12%5%2432336%6%48%
1986
16th to endDay
6%313433447%56%
1859
October1st to 15thDay
13%423323335%52%
1724
16th to endDay
8%6%1342333359%
1742
November1st to 15thDay
6%313323346%59%
1583
16th to endDay
10%6%23322346%55%
1620
December1st to 15thDay
9%9%36%5%235%47%43%
1620
16th to endDay
10%7%46%5%34446%41%
1728
January1st to 15thNight
7%5%36%434346%52%
2327
16th to endNight
7%5%24323345%57%
2496
February1st to 15thNight
9%8%35%5%2445%6%42%
2246
16th to endNight
6%6%25%5%2445%6%51%
1894
March1st to 15thNight
8%6%24322348%52%
2037
16th to endNight
15%7%23414346%44%
2112
April1st to 15thNight
11%425%424447%49%
1879
16th to endNight
14%7%25%31325%7%44%
1620
May1st to 15thNight
13%6%35%5%235%5%7%41%
1619
16th to endNight
11%413415%36%9%46%
1683
June1st to 15thNight
5%31332446%9%55%
1620
16th to endNight
21123235%6%10%60%
1620
July1st to 15thNight
3213435%5%6%10%52%
1620
16th to endNight
42144245%6%11%51%
1702
August1st to 15thNight
5%2124245%7%9%54%
1620
16th to endNight
5%313423347%58%
1738
September1st to 15thNight
8%31342345%7%56%
1974
16th to endNight
5%314323446%59%
1870
October1st to 15thNight
13%313323345%55%
1895
16th to endNight
9%312223235%62%
2128
November1st to 15thNight
5%213322347%63%
2275
16th to endNight
9%413322436%57%
2340
December1st to 15thNight
9%6%2442345%7%48%
2340
16th to endNight
12%7%3422235%8%47%
2496

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
6%5%245%25%45%7%50%
1611
16th to endDay
7%6%26%42445%7%48%
1728
February1st to 15thDay
8%9%35%434447%43%
1615
16th to endDay
6%7%25%5%34445%50%
1580
March1st to 15thDay
8%6%144245%5%7%48%
1923
16th to endDay
15%8%34423446%42%
2110
April1st to 15thDay
14%7%24323346%45%
2066
16th to endDay
18%6%26%4245%5%6%37%
2340
May1st to 15thDay
13%5%244345%46%44%
2331
16th to endDay
13%5%25%43445%7%41%
2430
June1st to 15thDay
7%42343445%8%52%
2340
16th to endDay
3213325%5%6%8%56%
2340
July1st to 15thDay
7%323425%5%7%9%48%
2340
16th to endDay
6%214425%46%9%51%
2466
August1st to 15thDay
6%3145%345%7%9%47%
2340
16th to endDay
7%41242345%7%55%
2462
September1st to 15thDay
12%5%2342336%6%48%
1986
16th to endDay
6%31442345%7%56%
1859
October1st to 15thDay
13%423323435%52%
1724
16th to endDay
8%6%1341323459%
1742
November1st to 15thDay
7%313323446%59%
1583
16th to endDay
10%6%23323336%55%
1620
December1st to 15thDay
9%9%35%4235%46%43%
1620
16th to endDay
11%6%46%5%34446%41%
1728
January1st to 15thNight
7%5%26%333346%52%
2327
16th to endNight
7%5%24323345%56%
2496
February1st to 15thNight
9%8%35%5%245%5%6%42%
2246
16th to endNight
6%6%245%2445%6%51%
1894
March1st to 15thNight
8%6%24322348%52%
2037
16th to endNight
15%7%23414346%44%
2112
April1st to 15thNight
11%5%24424446%49%
1879
16th to endNight
14%7%35%32325%7%44%
1620
May1st to 15thNight
13%6%25%5%235%5%7%42%
1619
16th to endNight
11%41342436%10%46%
1683
June1st to 15thNight
5%31332445%9%55%
1620
16th to endNight
211322346%10%60%
1620
July1st to 15thNight
3212435%5%6%10%53%
1620
16th to endNight
42134245%7%11%52%
1702
August1st to 15thNight
5%2124245%6%9%54%
1620
16th to endNight
5%313323347%58%
1738
September1st to 15thNight
8%313323447%56%
1974
16th to endNight
5%313323447%59%
1870
October1st to 15thNight
13%322423345%55%
1895
16th to endNight
9%312213235%62%
2128
November1st to 15thNight
5%213322347%64%
2275
16th to endNight
9%413313446%57%
2340
December1st to 15thNight
9%6%25%42335%7%48%
2340
16th to endNight
12%7%3422235%7%47%
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
32%5%16%28%14%1
1612
16th to endDay
34%419%24%14%1
1728
February1st to 15thDay
40%6%17%22%9%3
1616
16th to endDay
34%6%13%25%17%2
1580
March1st to 15thDay
33%6%13%26%17%2
1923
16th to endDay
43%5%12%24%11%1
2112
April1st to 15thDay
39%5%13%24%15%1
2066
16th to endDay
45%7%11%23%12%
2340
May1st to 15thDay
40%6%11%24%15%1
2331
16th to endDay
40%7%14%24%11%1
2434
June1st to 15thDay
28%8%16%27%15%3
2340
16th to endDay
22%7%15%31%20%3
2340
July1st to 15thDay
30%7%13%26%17%3
2201
16th to endDay
26%6%14%31%18%2
2311
August1st to 15thDay
30%8%15%27%14%2
2326
16th to endDay
27%5%12%28%19%5%
2462
September1st to 15thDay
34%5%11%22%19%5%
1986
16th to endDay
27%6%12%29%21%2
1859
October1st to 15thDay
34%48%23%25%3
1724
16th to endDay
28%48%29%23%5%
1742
November1st to 15thDay
25%410%27%27%4
1583
16th to endDay
31%311%30%20%2
1620
December1st to 15thDay
39%6%15%25%11%
1620
16th to endDay
43%414%23%12%
1728
January1st to 15thNight
33%315%27%17%1
2327
16th to endNight
28%415%29%17%3
2496
February1st to 15thNight
42%6%13%23%11%2
2256
16th to endNight
32%5%13%25%17%5%
1894
March1st to 15thNight
30%5%13%25%19%6%
2037
16th to endNight
40%5%14%23%12%3
2112
April1st to 15thNight
34%6%12%24%20%1
1879
16th to endNight
38%414%24%16%1
1620
May1st to 15thNight
40%7%12%22%15%2
1620
16th to endNight
32%7%21%22%13%2
1685
June1st to 15thNight
25%7%17%28%16%4
1620
16th to endNight
18%5%16%33%22%5%
1620
July1st to 15thNight
22%8%15%30%18%3
1530
16th to endNight
23%7%16%29%19%3
1594
August1st to 15thNight
23%8%17%30%14%5%
1610
16th to endNight
25%5%12%27%20%7%
1738
September1st to 15thNight
27%5%12%27%17%9%
1974
16th to endNight
25%5%11%26%27%4
1870
October1st to 15thNight
31%5%9%24%24%5%
1895
16th to endNight
24%310%28%26%5%
2128
November1st to 15thNight
20%410%27%29%7%
2275
16th to endNight
27%410%29%22%4
2340
December1st to 15thNight
33%6%15%29%15%
2340
16th to endNight
36%415%25%15%2
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
17%11%38%23%8%
90
16th to endDay
16%7%39%30%6%
96
February1st to 15thDay
12%16%36%28%5%
90
16th to endDay
417%41%24%8%2
81
March1st to 15thDay
16%16%41%21%4
90
16th to endDay
19%13%40%19%6%
96
April1st to 15thDay
17%11%42%22%5%
185
16th to endDay
24%12%33%20%7%1
450
May1st to 15thDay
15%10%31%28%12%2
468
16th to endDay
17%9%31%29%10%2
517
June1st to 15thDay
6%430%34%18%4
495
16th to endDay
45%32%37%18%1
495
July1st to 15thDay
9%118%41%24%4
475
16th to endDay
6%112%44%29%4
515
August1st to 15thDay
7%115%43%29%2
493
16th to endDay
10%221%34%26%5%
502
September1st to 15thDay
9%231%35%17%3
141
16th to endDay
13%6%16%38%20%3
102
October1st to 15thDay
18%5%21%38%13%2
90
16th to endDay
6%5%43%33%10%1
96
November1st to 15thDay
11%7%30%26%20%4
90
16th to endDay
30%11%35%18%4
90
December1st to 15thDay
13%16%43%20%33
90
16th to endDay
22%13%37%22%3
96
January1st to 15thNight
10%9%34%37%6%
900
16th to endNight
10%9%36%36%6%
960
February1st to 15thNight
13%9%38%35%4
848
16th to endNight
10%11%41%29%6%
632
March1st to 15thNight
12%11%34%34%7%
597
16th to endNight
19%9%38%25%6%
576
April1st to 15thNight
13%10%39%30%5%
539
16th to endNight
16%11%36%27%7%
540
May1st to 15thNight
16%8%33%30%9%1
540
16th to endNight
13%6%32%34%11%1
563
June1st to 15thNight
7%235%40%12%1
540
16th to endNight
3233%45%14%
540
July1st to 15thNight
5%21%49%21%
510
16th to endNight
415%51%25%1
564
August1st to 15thNight
6%14%54%24%
539
16th to endNight
6%119%44%26%2
573
September1st to 15thNight
9%326%37%20%2
540
16th to endNight
8%328%40%17%1
507
October1st to 15thNight
15%8%28%32%15%
575
16th to endNight
12%6%32%36%10%
720
November1st to 15thNight
7%9%32%37%12%
875
16th to endNight
11%10%34%33%8%1
900
December1st to 15thNight
13%9%36%34%5%
900
16th to endNight
16%7%31%35%8%
960
Page generated at 2017-09-21 06:18:23. Version ac04

Copyright 2017 A. Danko


Concordia Clear Sky Chart | Charts Home