Harmony
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Harmony clear sky chart from 2005-11-06 to 2024-01-13.

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
60%
24653
19%
74494
16%
24600
64%
24600
28%
47506

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 10thNight
45%
758
22%
2459
16%
757
55%
757
28%
1458
January11th to 20thNight
51%
729
25%
2367
20%
729
61%
729
30%
1381
January21st to endNight
42%
792
22%
2542
16%
792
52%
792
26%
1572
February1st to 10thNight
48%
720
22%
2160
16%
720
55%
720
30%
1325
February11th to 20thNight
50%
700
24%
2099
15%
700
61%
700
35%
1221
February21st to endNight
50%
592
30%
1633
20%
592
58%
592
40%
938
March1st to 10thNight
50%
720
30%
1980
18%
720
60%
720
45%
1081
March11th to 20thNight
55%
720
27%
1980
20%
720
61%
720
40%
1137
March21st to endNight
55%
792
29%
2178
20%
792
62%
792
42%
1225
April1st to 10thNight
57%
720
24%
1980
18%
720
61%
720
43%
1109
April11th to 20thNight
56%
711
20%
1893
15%
711
59%
711
35%
1175
April21st to endNight
61%
720
27%
1800
17%
720
64%
720
45%
1058
May1st to 10thNight
66%
671
27%
1751
18%
671
70%
671
45%
995
May11th to 20thNight
67%
531
15%
1592
12%
531
68%
531
31%
995
May21st to endNight
72%
582
20%
1745
16%
582
73%
582
29%
1130
June1st to 10thNight
65%
540
12%
1620
10%
540
65%
540
21%
1158
June11th to 20thNight
71%
540
13%
1620
11%
540
72%
540
24%
1130
June21st to endNight
72%
540
9%
1620
8%
540
72%
540
21%
1164
July1st to 10thNight
68%
525
5%
1575
4%
525
68%
525
17%
1188
July11th to 20thNight
72%
522
6%
1566
6%
522
72%
522
20%
1149
July21st to endNight
74%
591
9%
1672
8%
558
75%
558
20%
1223
August1st to 10thNight
75%
537
7%
1600
6%
534
76%
534
23%
1128
August11th to 20thNight
76%
605
6%
1669
6%
605
76%
605
21%
1217
August21st to endNight
62%
792
7%
2175
7%
792
62%
792
17%
1652
September1st to 10thNight
66%
720
8%
1980
7%
720
66%
720
16%
1505
September11th to 20thNight
59%
720
7%
1980
7%
720
59%
720
17%
1501
September21st to endNight
62%
720
15%
1980
15%
720
62%
720
20%
1437
October1st to 10thNight
64%
720
19%
2026
19%
720
66%
720
27%
1357
October11th to 20thNight
69%
720
26%
2160
26%
720
73%
720
33%
1283
October21st to endNight
64%
792
25%
2376
24%
792
68%
792
33%
1414
November1st to 10thNight
59%
740
24%
2221
21%
740
65%
740
33%
1322
November11th to 20thNight
58%
760
25%
2280
22%
760
63%
760
30%
1420
November21st to endNight
54%
760
25%
2318
22%
760
61%
760
30%
1440
December1st to 10thNight
60%
760
27%
2470
23%
760
69%
760
33%
1419
December11th to 20thNight
52%
760
22%
2953
21%
758
58%
758
23%
1757
December21st to endNight
53%
831
14%
4474
20%
817
59%
817
15%
2842

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
8%5%37%7%47%7%7%9%36%
74882
Night
8%5%26%6%35%6%6%9%43%
74848
TransparencyDay
41%10%14%16%13%5%
74605
Night
35%10%16%20%14%5%
74644
SeeingDay
9%417%25%24%21%
14529
Night
9%318%33%29%9%
24665

By Month

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 10thDay
11%6%35%5%25%5%5%8%45%
1706
11th to 20thDay
7%5%25%5%35%5%6%10%48%
1638
21st to endDay
13%5%36%5%35%45%6%45%
1809
February1st to 10thDay
12%5%36%5%245%6%8%44%
1800
11th to 20thDay
6%4345%35%5%6%7%52%
1748
21st to endDay
9%5%26%6%35%5%6%6%48%
1620
March1st to 10thDay
4325%5%4446%8%54%
1980
11th to 20thDay
7%325%6%45%6%6%9%47%
1980
21st to endDay
6%425%6%36%5%6%7%50%
2178
April1st to 10thDay
6%325%6%5%6%6%7%8%46%
1980
11th to 20thDay
8%5%36%7%46%8%6%8%39%
2016
21st to endDay
5%435%7%45%5%6%9%48%
2160
May1st to 10thDay
5%314435%5%6%9%54%
2222
11th to 20thDay
8%5%37%7%5%7%7%7%8%38%
2301
21st to endDay
7%5%38%8%5%8%7%7%9%32%
2531
June1st to 10thDay
13%7%49%10%5%7%6%8%10%21%
2340
11th to 20thDay
7%5%37%9%6%9%9%8%10%27%
2340
21st to endDay
10%7%38%9%6%8%7%7%9%26%
2340
July1st to 10thDay
8%7%49%10%5%9%9%9%9%22%
2340
11th to 20thDay
8%6%49%9%6%8%8%8%10%24%
2340
21st to endDay
7%7%49%10%5%9%9%8%10%22%
2547
August1st to 10thDay
6%5%39%9%6%8%9%11%10%24%
2327
11th to 20thDay
6%5%310%10%6%10%8%8%11%24%
2208
21st to endDay
10%7%48%9%5%8%7%8%10%23%
2178
September1st to 10thDay
7%6%38%11%6%8%9%7%11%23%
1980
11th to 20thDay
10%6%39%8%6%7%10%8%9%23%
1980
21st to endDay
10%8%48%9%5%7%7%8%9%26%
1980
October1st to 10thDay
10%7%37%9%5%6%7%7%9%31%
1931
11th to 20thDay
7%5%25%6%46%6%7%9%43%
1800
21st to endDay
8%435%6%35%6%6%8%46%
1980
November1st to 10thDay
6%426%7%36%7%6%10%43%
1857
11th to 20thDay
10%5%36%7%35%5%6%7%42%
1900
21st to endDay
8%6%36%6%46%5%7%10%39%
1858
December1st to 10thDay
8%5%46%6%46%46%8%44%
1710
11th to 20thDay
10%7%36%5%5%5%5%6%7%41%
2153
21st to endDay
11%6%37%8%47%6%7%7%33%
3124
January1st to 10thNight
10%6%25%5%345%6%9%46%
2459
11th to 20thNight
8%5%245%35%6%5%9%47%
2367
21st to endNight
11%6%36%5%35%5%5%6%45%
2542
February1st to 10thNight
11%6%35%5%3445%7%47%
2160
11th to 20thNight
10%4245%3445%7%52%
2098
21st to endNight
8%3245%345%6%9%53%
1633
March1st to 10thNight
5%31443445%8%59%
1980
11th to 20thNight
8%32443345%9%54%
1980
21st to endNight
5%324435%45%8%56%
2178
April1st to 10thNight
6%32443445%10%56%
1980
11th to 20thNight
6%425%6%35%6%6%10%47%
1893
21st to endNight
5%3243346%6%10%55%
1800
May1st to 10thNight
43145%3445%9%59%
1751
11th to 20thNight
6%5%26%5%45%5%7%8%47%
1592
21st to endNight
6%5%36%5%47%7%8%9%41%
1744
June1st to 10thNight
11%8%46%6%46%7%7%11%31%
1620
11th to 20thNight
6%6%26%6%47%7%8%13%33%
1620
21st to endNight
7%7%46%7%47%6%9%12%31%
1620
July1st to 10thNight
8%6%38%8%5%7%8%8%11%30%
1620
11th to 20thNight
5%6%39%7%5%6%6%9%12%32%
1620
21st to endNight
5%5%36%8%47%8%9%11%32%
1771
August1st to 10thNight
5%5%27%7%46%7%9%13%35%
1611
11th to 20thNight
5%5%36%7%6%8%9%10%12%31%
1669
21st to endNight
10%6%37%8%47%7%7%10%30%
2175
September1st to 10thNight
7%6%28%7%49%8%9%11%29%
1980
11th to 20thNight
9%8%47%8%46%7%7%10%28%
1980
21st to endNight
11%7%38%6%46%7%7%9%33%
1980
October1st to 10thNight
9%7%25%6%5%5%6%7%9%40%
2026
11th to 20thNight
6%5%35%435%5%6%8%50%
2160
21st to endNight
9%5%25%4345%5%8%49%
2376
November1st to 10thNight
9%425%5%35%5%5%7%50%
2221
11th to 20thNight
9%5%35%5%35%5%6%9%46%
2280
21st to endNight
10%5%35%5%35%5%7%9%43%
2318
December1st to 10thNight
7%424446%5%6%9%49%
2470
11th to 20thNight
13%7%25%5%34446%47%
3042
21st to endNight
12%7%37%7%45%6%6%7%37%
4532

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 10thDay
37%6%8%21%19%9%
1707
11th to 20thDay
30%7%9%23%24%8%
1638
21st to endDay
39%5%8%17%21%10%
1809
February1st to 10thDay
37%8%10%15%20%9%
1800
11th to 20thDay
30%6%10%20%23%10%
1758
21st to endDay
37%5%10%15%26%8%
1620
March1st to 10thDay
29%6%12%21%24%8%
1980
11th to 20thDay
32%7%12%24%16%9%
1980
21st to endDay
31%6%12%23%20%8%
2178
April1st to 10thDay
34%8%14%22%16%7%
1980
11th to 20thDay
40%9%11%17%18%5%
2016
21st to endDay
32%6%12%19%24%8%
2160
May1st to 10thDay
26%7%13%22%24%9%
2222
11th to 20thDay
40%10%14%18%16%2
2305
21st to endDay
45%10%12%16%15%2
2531
June1st to 10thDay
54%13%16%13%4
2340
11th to 20thDay
47%14%20%16%3
2340
21st to endDay
51%14%20%12%31
2340
July1st to 10thDay
53%17%20%9%2
2275
11th to 20thDay
50%17%21%11%
2271
21st to endDay
51%17%20%11%1
2405
August1st to 10thDay
46%18%26%9%1
2314
11th to 20thDay
50%17%23%9%1
2208
21st to endDay
52%18%19%8%3
2178
September1st to 10thDay
51%17%18%10%4
1980
11th to 20thDay
51%16%20%11%3
1980
21st to endDay
50%14%14%11%9%2
1980
October1st to 10thDay
46%10%13%15%11%5%
1931
11th to 20thDay
36%8%12%21%20%4
1800
21st to endDay
33%7%12%18%20%10%
1980
November1st to 10thDay
34%8%12%18%19%9%
1857
11th to 20thDay
39%8%9%19%19%7%
1900
21st to endDay
39%7%11%19%19%6%
1858
December1st to 10thDay
37%7%13%22%15%5%
1710
11th to 20thDay
39%7%11%15%17%10%
2150
21st to endDay
45%9%12%16%12%6%
3124
January1st to 10thNight
34%7%11%20%19%8%
2459
11th to 20thNight
33%6%10%24%19%7%
2367
21st to endNight
38%7%10%20%16%9%
2542
February1st to 10thNight
36%6%12%17%19%10%
2160
11th to 20thNight
30%6%11%20%22%10%
2099
21st to endNight
28%6%15%20%24%7%
1633
March1st to 10thNight
23%6%14%28%23%7%
1980
11th to 20thNight
27%6%15%27%16%8%
1980
21st to endNight
25%7%14%26%21%8%
2178
April1st to 10thNight
25%6%20%25%16%7%
1980
11th to 20thNight
30%10%15%23%18%5%
1893
21st to endNight
24%7%16%23%23%7%
1800
May1st to 10thNight
23%7%12%27%21%9%
1751
11th to 20thNight
33%10%20%23%12%2
1593
21st to endNight
34%11%16%20%18%1
1745
June1st to 10thNight
45%12%22%18%5%
1620
11th to 20thNight
39%14%22%23%3
1620
21st to endNight
42%14%23%15%5%
1620
July1st to 10thNight
46%16%26%10%2
1575
11th to 20thNight
43%15%29%13%1
1566
21st to endNight
39%20%28%13%1
1672
August1st to 10thNight
37%17%34%12%1
1600
11th to 20thNight
38%19%30%11%1
1669
21st to endNight
46%16%23%13%2
2175
September1st to 10thNight
43%20%20%13%3
1980
11th to 20thNight
46%16%19%16%2
1980
21st to endNight
45%13%17%14%9%2
1980
October1st to 10thNight
38%11%15%20%12%5%
2026
11th to 20thNight
32%7%12%24%20%4
2160
21st to endNight
32%7%13%18%22%9%
2376
November1st to 10thNight
32%7%14%19%20%8%
2221
11th to 20thNight
34%9%13%21%16%8%
2280
21st to endNight
36%8%11%21%19%5%
2318
December1st to 10thNight
29%9%15%28%13%6%
2470
11th to 20thNight
38%6%11%18%17%11%
3044
21st to endNight
44%9%13%17%13%5%
4532

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 10thDay
11%9%42%26%10%2
270
11th to 20thDay
6%10%35%31%15%4
246
21st to endDay
14%13%40%24%8%
264
February1st to 10thDay
10%11%31%27%17%3
240
11th to 20thDay
5%6%33%34%15%7%
240
21st to endDay
7%8%27%31%23%3
338
March1st to 10thDay
5%8%34%35%17%1
420
11th to 20thDay
9%6%26%31%24%4
420
21st to endDay
6%7%24%32%26%5%
462
April1st to 10thDay
6%7%30%30%23%5%
420
11th to 20thDay
10%7%24%33%17%9%
412
21st to endDay
6%420%32%24%13%
420
May1st to 10thDay
6%120%28%32%12%
423
11th to 20thDay
10%213%25%30%20%
447
21st to endDay
8%29%24%27%29%
485
June1st to 10thDay
16%310%19%29%24%
450
11th to 20thDay
7%17%20%27%39%
450
21st to endDay
9%2416%24%46%
450
July1st to 10thDay
7%1410%24%53%
445
11th to 20thDay
6%39%32%49%
444
21st to endDay
9%1314%23%50%
488
August1st to 10thDay
7%15%13%26%47%
446
11th to 20thDay
7%410%26%52%
439
21st to endDay
12%17%15%26%40%
495
September1st to 10thDay
9%15%13%28%44%
450
11th to 20thDay
9%110%19%25%36%
450
21st to endDay
10%17%18%34%29%
450
October1st to 10thDay
13%315%34%24%11%
450
11th to 20thDay
7%5%15%30%33%11%
450
21st to endDay
8%318%36%28%7%
495
November1st to 10thDay
8%418%33%28%8%
455
11th to 20thDay
11%7%23%33%23%4
460
21st to endDay
10%6%23%36%22%3
418
December1st to 10thDay
8%8%29%32%17%6%
270
11th to 20thDay
11%7%28%33%17%3
270
21st to endDay
6%9%28%34%19%4
297
January1st to 10thNight
11%8%28%35%16%1
760
11th to 20thNight
10%5%26%43%14%1
729
21st to endNight
12%8%31%38%11%1
792
February1st to 10thNight
13%5%26%39%15%
720
11th to 20thNight
10%6%29%40%14%1
703
21st to endNight
9%5%32%42%12%
592
March1st to 10thNight
6%5%33%43%13%1
720
11th to 20thNight
8%5%26%42%18%1
720
21st to endNight
6%428%44%18%1
792
April1st to 10thNight
6%5%27%45%16%1
720
11th to 20thNight
7%5%24%46%18%1
711
21st to endNight
6%323%44%22%1
720
May1st to 10thNight
6%218%45%27%2
671
11th to 20thNight
8%212%37%36%5%
531
21st to endNight
8%27%30%46%7%
584
June1st to 10thNight
13%16%25%46%8%
540
11th to 20thNight
6%2417%47%23%
540
21st to endNight
9%1416%48%23%
540
July1st to 10thNight
8%1312%47%29%
525
11th to 20thNight
5%48%51%32%
522
21st to endNight
5%411%46%33%
591
August1st to 10thNight
5%310%51%30%
537
11th to 20thNight
5%412%44%35%
605
21st to endNight
10%17%18%41%23%
792
September1st to 10thNight
10%15%16%43%25%
720
11th to 20thNight
12%19%18%44%16%
720
21st to endNight
14%18%22%43%13%
720
October1st to 10thNight
11%113%35%32%7%
720
11th to 20thNight
6%311%35%39%6%
720
21st to endNight
11%214%37%32%4
792
November1st to 10thNight
9%420%34%30%3
740
11th to 20thNight
9%5%21%40%24%2
760
21st to endNight
12%423%42%19%1
760
December1st to 10thNight
6%423%39%26%2
760
11th to 20thNight
11%6%22%38%22%2
760
21st to endNight
9%7%24%40%20%1
836
Page generated at 2024-01-10 01:25:05. Version ac07

Copyright 2024 Attilla Danko


Harmony Clear Sky Chart |Charts Home