Riverfront Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Riverfront Park clear sky chart from 2005-11-06 to 2024-03-06.

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
34%
24653
20%
80449
12%
24543
43%
24543
22%
51999

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
16%
942
14%
4368
5%
926
28%
926
11%
2988
January11th to 20thNight
18%
950
16%
4047
6%
930
28%
930
11%
2981
January21st to endNight
17%
1038
12%
4485
5%
1023
26%
1023
10%
3356
February1st to 10thNight
17%
950
16%
2470
3%
950
24%
950
17%
1811
February11th to 20thNight
17%
823
18%
2299
4%
820
27%
820
18%
1561
February21st to endNight
14%
628
19%
1884
4%
628
26%
628
18%
1269
March1st to 10thNight
17%
662
20%
2146
6%
662
30%
662
20%
1366
March11th to 20thNight
20%
540
17%
1980
9%
540
31%
540
15%
1331
March21st to endNight
15%
594
11%
2110
5%
594
23%
594
11%
1534
April1st to 10thNight
24%
540
21%
1800
9%
540
40%
540
23%
1073
April11th to 20thNight
26%
533
21%
1775
14%
533
38%
533
22%
1092
April21st to endNight
24%
540
20%
1800
8%
540
40%
540
21%
1158
May1st to 10thNight
31%
540
15%
1746
9%
540
40%
540
23%
1116
May11th to 20thNight
37%
531
19%
1435
13%
531
42%
531
27%
962
May21st to endNight
45%
584
18%
1551
9%
582
52%
582
29%
1032
June1st to 10thNight
57%
540
20%
1440
15%
540
61%
540
39%
873
June11th to 20thNight
53%
540
25%
1440
14%
540
61%
540
40%
860
June21st to endNight
54%
540
24%
1440
13%
540
60%
540
46%
811
July1st to 10thNight
66%
525
19%
1400
14%
525
68%
525
37%
858
July11th to 20thNight
65%
522
24%
1409
18%
522
69%
522
47%
781
July21st to endNight
64%
591
23%
1673
20%
558
68%
558
37%
962
August1st to 10thNight
70%
537
23%
1601
25%
534
73%
534
39%
899
August11th to 20thNight
67%
534
25%
1725
27%
534
71%
534
37%
944
August21st to endNight
67%
594
26%
1980
29%
594
71%
594
39%
1036
September1st to 10thNight
57%
540
26%
1800
25%
540
63%
540
34%
984
September11th to 20thNight
60%
540
33%
1800
31%
540
68%
540
34%
997
September21st to endNight
53%
679
31%
2018
22%
679
61%
679
37%
1123
October1st to 10thNight
46%
720
27%
2160
18%
720
54%
720
39%
1179
October11th to 20thNight
31%
720
29%
2160
14%
720
45%
720
29%
1296
October21st to endNight
25%
792
23%
2376
11%
792
37%
792
24%
1500
November1st to 10thNight
32%
740
28%
2360
14%
740
48%
740
31%
1309
November11th to 20thNight
26%
760
27%
2470
13%
760
44%
760
25%
1448
November21st to endNight
24%
902
21%
2612
9%
902
35%
902
24%
1698
December1st to 10thNight
23%
950
18%
2660
6%
950
34%
950
19%
1851
December11th to 20thNight
23%
949
19%
3159
8%
948
32%
948
18%
2117
December21st to endNight
15%
1043
10%
4870
5%
1026
26%
1026
8%
3843

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
13%7%36%5%3445%7%42%
78619
Night
14%8%36%5%3445%6%43%
80954
TransparencyDay
41%6%11%23%15%2
78331
Night
42%5%10%23%16%3
80762
SeeingDay
18%13%29%25%12%3
14634
Night
19%13%30%26%11%1
24671

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%13%6%10%6%35%447%31%
2527
11th to 20thDay
13%11%47%8%6%5%446%34%
2850
21st to endDay
20%15%7%6%5%33345%30%
3135
February1st to 10thDay
15%11%5%8%5%34446%35%
1710
11th to 20thDay
15%9%46%5%3445%6%39%
1767
21st to endDay
16%11%37%5%3435%5%39%
1570
March1st to 10thDay
14%9%46%6%3445%6%40%
1945
11th to 20thDay
19%8%5%7%5%34446%35%
1980
21st to endDay
21%11%48%5%3445%6%29%
2245
April1st to 10thDay
12%6%35%6%45%45%5%45%
2160
11th to 20thDay
19%8%25%434445%41%
2134
21st to endDay
21%7%35%6%35%45%6%35%
2160
May1st to 10thDay
17%7%46%5%345%5%9%36%
2211
11th to 20thDay
16%6%35%4346%5%7%40%
2461
21st to endDay
12%6%37%6%35%6%6%9%38%
2725
June1st to 10thDay
9%425%4346%7%10%47%
2520
11th to 20thDay
8%3245%345%6%10%48%
2520
21st to endDay
5%325%5%46%6%7%9%48%
2520
July1st to 10thDay
10%4245%46%5%7%11%44%
2520
11th to 20thDay
5%324435%5%7%10%52%
2499
21st to endDay
9%5%245%35%6%7%9%45%
2546
August1st to 10thDay
8%436%5%45%5%7%10%43%
2328
11th to 20thDay
9%5%25%6%35%6%8%9%42%
2176
21st to endDay
8%425%5%2446%7%52%
2376
September1st to 10thDay
13%5%25%435%45%7%49%
2160
11th to 20thDay
10%42343445%8%52%
2160
21st to endDay
8%425%33445%8%54%
1920
October1st to 10thDay
11%425%434446%54%
1800
11th to 20thDay
16%6%24423235%52%
1800
21st to endDay
19%8%2442333447%
1980
November1st to 10thDay
11%6%2443235%6%55%
1718
11th to 20thDay
14%8%35%42345%6%47%
1710
21st to endDay
17%9%45%423345%44%
1565
December1st to 10thDay
13%10%47%334447%41%
1520
11th to 20thDay
15%10%46%5%33447%40%
1918
21st to endDay
18%14%5%10%6%34445%25%
2783
January1st to 10thNight
13%11%8%8%6%3344435%
4424
11th to 20thNight
14%9%410%7%5%7%5%3430%
4120
21st to endNight
23%16%6%6%43334429%
4532
February1st to 10thNight
15%11%5%8%6%35%446%34%
2470
11th to 20thNight
15%7%48%5%245%5%5%41%
2298
21st to endNight
17%10%36%5%2334441%
1884
March1st to 10thNight
17%10%35%43334445%
2146
11th to 20thNight
19%8%45%6%245%45%37%
1980
21st to endNight
21%9%47%5%35%5%6%6%28%
2110
April1st to 10thNight
11%7%36%41445%6%48%
1800
11th to 20thNight
14%7%36%43335%7%44%
1775
21st to endNight
19%6%35%5%3445%6%42%
1800
May1st to 10thNight
15%6%3443446%8%43%
1746
11th to 20thNight
16%7%245%44447%44%
1434
21st to endNight
11%5%345%445%7%8%42%
1551
June1st to 10thNight
7%4245%35%46%8%52%
1440
11th to 20thNight
6%425%4345%5%10%51%
1440
21st to endNight
5%2244335%6%9%56%
1440
July1st to 10thNight
9%3245%345%7%10%50%
1440
11th to 20thNight
5%41433345%10%57%
1457
21st to endNight
7%426%5%345%7%8%51%
1772
August1st to 10thNight
7%315%5%445%6%10%51%
1611
11th to 20thNight
7%43343446%9%53%
1725
21st to endNight
6%32442446%7%57%
1980
September1st to 10thNight
13%5%24323347%54%
1800
11th to 20thNight
9%4244335%6%7%53%
1800
21st to endNight
7%4245%3445%5%58%
2018
October1st to 10thNight
9%424424346%58%
2160
11th to 20thNight
14%5%3442335%6%51%
2160
21st to endNight
19%7%24424335%48%
2376
November1st to 10thNight
10%5%24324345%56%
2360
11th to 20thNight
14%6%35%423445%50%
2470
21st to endNight
17%9%35%323345%45%
2612
December1st to 10thNight
14%10%46%6%35%45%6%37%
2660
11th to 20thNight
17%9%46%434345%40%
3279
21st to endNight
20%19%6%8%6%3443423%
4884

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
52%5%10%22%9%1
2528
11th to 20thDay
50%6%12%21%12%
2850
21st to endDay
57%410%15%13%1
3135
February1st to 10thDay
53%410%21%11%1
1710
11th to 20thDay
47%411%20%15%4
1776
21st to endDay
47%49%21%14%4
1570
March1st to 10thDay
46%49%23%16%2
1945
11th to 20thDay
52%5%9%18%13%2
1980
21st to endDay
57%5%10%17%9%1
2245
April1st to 10thDay
40%6%11%24%18%1
2160
11th to 20thDay
45%5%10%22%14%3
2134
21st to endDay
49%5%10%21%13%1
2160
May1st to 10thDay
47%7%13%22%11%1
2211
11th to 20thDay
44%8%11%22%14%2
2465
21st to endDay
42%9%14%20%14%2
2725
June1st to 10thDay
32%9%14%29%15%2
2520
11th to 20thDay
30%8%13%26%19%4
2520
21st to endDay
29%9%17%25%15%5%
2520
July1st to 10thDay
33%9%15%27%12%4
2451
11th to 20thDay
26%8%16%29%18%3
2424
21st to endDay
33%8%15%29%14%2
2405
August1st to 10thDay
35%9%15%27%13%1
2314
11th to 20thDay
35%10%12%27%14%1
2176
21st to endDay
31%7%12%24%21%6%
2376
September1st to 10thDay
34%6%11%26%19%4
2160
11th to 20thDay
31%6%9%26%25%3
2160
21st to endDay
29%6%10%28%24%3
1920
October1st to 10thDay
32%5%9%26%24%4
1800
11th to 20thDay
37%38%25%22%5%
1800
21st to endDay
43%38%25%17%4
1980
November1st to 10thDay
31%413%25%22%5%
1718
11th to 20thDay
38%49%24%21%4
1710
21st to endDay
44%49%27%15%
1565
December1st to 10thDay
44%412%27%12%1
1520
11th to 20thDay
46%410%23%14%2
1915
21st to endDay
61%5%9%14%9%1
2783
January1st to 10thNight
53%5%9%23%10%1
4424
11th to 20thNight
58%48%20%9%1
4120
21st to endNight
59%5%9%20%7%1
4532
February1st to 10thNight
51%5%10%19%13%2
2470
11th to 20thNight
45%5%10%21%17%3
2299
21st to endNight
47%310%20%15%4
1884
March1st to 10thNight
44%49%23%17%3
2146
11th to 20thNight
49%6%9%21%13%3
1980
21st to endNight
56%6%10%19%8%1
2110
April1st to 10thNight
36%5%11%26%18%3
1800
11th to 20thNight
40%5%10%24%16%5%
1775
21st to endNight
44%5%9%24%18%1
1800
May1st to 10thNight
39%8%14%21%16%1
1746
11th to 20thNight
41%7%13%22%15%2
1435
21st to endNight
38%8%16%19%17%2
1552
June1st to 10thNight
29%7%15%29%17%3
1440
11th to 20thNight
28%7%11%27%24%3
1440
21st to endNight
23%7%18%28%19%6%
1440
July1st to 10thNight
29%9%13%30%15%4
1400
11th to 20thNight
22%7%15%28%24%3
1409
21st to endNight
29%7%12%33%18%1
1673
August1st to 10thNight
27%6%16%34%15%2
1601
11th to 20thNight
27%7%13%30%22%1
1725
21st to endNight
25%6%14%26%22%6%
1980
September1st to 10thNight
31%5%11%26%23%5%
1800
11th to 20thNight
29%6%11%23%26%4
1800
21st to endNight
27%6%9%26%28%4
2018
October1st to 10thNight
27%411%26%26%5%
2160
11th to 20thNight
35%5%7%28%20%6%
2160
21st to endNight
41%49%21%21%4
2376
November1st to 10thNight
31%413%26%20%6%
2360
11th to 20thNight
37%38%26%22%4
2470
21st to endNight
43%411%24%17%2
2612
December1st to 10thNight
48%5%10%23%12%1
2660
11th to 20thNight
47%49%24%15%1
3281
21st to endNight
65%5%8%13%7%1
4884

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
27%22%37%11%2
270
11th to 20thDay
34%24%31%11%1
270
21st to endDay
24%29%36%10%1
297
February1st to 10thDay
29%26%32%11%1
270
11th to 20thDay
33%23%29%11%2
270
21st to endDay
32%24%35%7%1
225
March1st to 10thDay
24%27%41%7%1
255
11th to 20thDay
33%25%30%12%1
240
21st to endDay
38%21%29%10%2
331
April1st to 10thDay
20%19%39%17%5%
420
11th to 20thDay
31%17%29%18%5%
412
21st to endDay
28%17%35%15%5%
420
May1st to 10thDay
21%19%35%18%7%1
474
11th to 20thDay
20%16%31%23%9%2
625
21st to endDay
15%13%32%25%12%4
679
June1st to 10thDay
10%6%29%34%16%5%
630
11th to 20thDay
10%5%28%41%14%3
630
21st to endDay
8%8%36%32%14%2
630
July1st to 10thDay
11%318%32%27%9%
621
11th to 20thDay
7%5%25%36%23%3
618
21st to endDay
10%323%34%26%4
684
August1st to 10thDay
10%419%41%22%4
626
11th to 20thDay
12%324%34%20%7%
490
21st to endDay
11%321%31%28%7%
495
September1st to 10thDay
12%6%18%35%23%6%
450
11th to 20thDay
10%323%31%23%10%
450
21st to endDay
10%10%22%34%18%5%
368
October1st to 10thDay
13%13%35%26%13%1
270
11th to 20thDay
25%21%32%18%4
270
21st to endDay
33%21%31%13%2
297
November1st to 10thDay
16%16%40%18%9%2
270
11th to 20thDay
26%20%27%23%32
270
21st to endDay
30%18%30%20%3
270
December1st to 10thDay
21%23%34%14%7%1
270
11th to 20thDay
26%20%33%18%3
270
21st to endDay
32%23%32%11%1
297
January1st to 10thNight
24%20%35%17%4
950
11th to 20thNight
27%21%32%17%3
950
21st to endNight
23%22%34%20%1
1045
February1st to 10thNight
24%21%36%17%2
950
11th to 20thNight
24%21%35%18%2
823
21st to endNight
29%20%35%15%2
628
March1st to 10thNight
24%18%37%19%2
662
11th to 20thNight
26%15%36%19%4
540
21st to endNight
29%16%35%16%4
594
April1st to 10thNight
19%20%35%21%41
540
11th to 20thNight
21%16%35%23%6%
533
21st to endNight
23%13%38%21%5%
540
May1st to 10thNight
16%12%36%27%8%
540
11th to 20thNight
19%9%29%31%11%1
531
21st to endNight
14%5%29%31%18%2
584
June1st to 10thNight
10%423%37%23%2
540
11th to 20thNight
8%329%41%18%1
540
21st to endNight
5%431%41%19%1
540
July1st to 10thNight
11%213%38%31%5%
525
11th to 20thNight
5%221%40%29%3
522
21st to endNight
8%219%40%30%2
591
August1st to 10thNight
7%314%47%29%2
537
11th to 20thNight
8%314%41%30%3
534
21st to endNight
7%219%37%32%3
594
September1st to 10thNight
14%320%35%23%5%
540
11th to 20thNight
11%418%36%27%4
540
21st to endNight
9%8%25%31%22%4
679
October1st to 10thNight
10%8%31%28%20%3
720
11th to 20thNight
18%15%33%26%8%1
720
21st to endNight
24%15%33%21%7%
792
November1st to 10thNight
14%14%37%25%10%
740
11th to 20thNight
20%18%33%22%7%
760
21st to endNight
25%17%32%21%5%
902
December1st to 10thNight
23%19%33%20%5%1
950
11th to 20thNight
27%14%32%24%4
950
21st to endNight
29%21%31%17%2
1045
Page generated at 2024-03-03 05:28:57. Version ac07

Copyright © 2024 Attilla Danko.


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