Greenville Recreation Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Greenville Recreation Area clear sky chart from 2005-11-06 to 2024-01-31.

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
41%
24361
23%
74814
15%
24301
50%
24301
28%
45810

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
22%
950
21%
2634
7%
946
34%
946
23%
1708
January11th to 20thNight
20%
950
23%
2470
7%
950
32%
950
23%
1665
January21st to endNight
22%
1043
23%
2711
6%
1043
33%
1043
26%
1812
February1st to 10thNight
20%
876
20%
2316
5%
876
30%
876
22%
1592
February11th to 20thNight
17%
703
20%
2099
7%
700
28%
700
21%
1347
February21st to endNight
18%
592
23%
1776
6%
592
32%
592
19%
1160
March1st to 10thNight
24%
696
21%
2136
7%
696
36%
696
24%
1347
March11th to 20thNight
29%
540
18%
1980
12%
540
38%
540
19%
1299
March21st to endNight
26%
594
15%
2069
10%
594
34%
594
17%
1416
April1st to 10thNight
30%
540
25%
1800
12%
540
48%
540
28%
1018
April11th to 20thNight
33%
533
24%
1775
16%
533
46%
533
25%
1062
April21st to endNight
28%
540
19%
1800
10%
540
42%
540
21%
1171
May1st to 10thNight
38%
540
18%
1800
11%
540
47%
540
26%
1084
May11th to 20thNight
42%
531
19%
1521
14%
531
46%
531
27%
995
May21st to endNight
50%
584
19%
1551
12%
582
55%
582
30%
1024
June1st to 10thNight
60%
540
20%
1440
15%
540
64%
540
35%
899
June11th to 20thNight
70%
540
28%
1440
21%
540
74%
540
50%
782
June21st to endNight
66%
540
26%
1440
18%
540
71%
540
48%
801
July1st to 10thNight
70%
525
19%
1400
16%
525
71%
525
38%
860
July11th to 20thNight
77%
522
22%
1413
20%
522
79%
522
44%
795
July21st to endNight
71%
591
24%
1673
24%
558
73%
558
39%
951
August1st to 10thNight
73%
537
21%
1652
23%
534
75%
534
35%
952
August11th to 20thNight
72%
534
25%
1776
29%
534
75%
534
36%
964
August21st to endNight
70%
594
25%
1980
28%
594
73%
594
36%
1069
September1st to 10thNight
67%
540
28%
1800
29%
540
70%
540
35%
979
September11th to 20thNight
65%
546
31%
1806
29%
546
70%
546
33%
1017
September21st to endNight
58%
720
31%
1980
21%
720
64%
720
41%
1126
October1st to 10thNight
58%
720
31%
2150
23%
720
64%
720
42%
1131
October11th to 20thNight
41%
720
32%
2160
18%
720
54%
720
35%
1220
October21st to endNight
35%
792
26%
2376
15%
792
47%
792
27%
1492
November1st to 10thNight
41%
740
30%
2378
21%
740
55%
740
37%
1267
November11th to 20thNight
36%
760
30%
2470
17%
760
53%
760
31%
1386
November21st to endNight
32%
760
24%
2470
16%
760
44%
760
25%
1506
December1st to 10thNight
32%
939
21%
2649
10%
939
42%
939
24%
1747
December11th to 20thNight
30%
948
23%
3122
11%
948
39%
948
21%
1969
December21st to endNight
22%
1041
12%
4801
7%
1026
34%
1026
13%
3197

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%6%25%5%345%5%7%44%
74891
Night
14%6%25%42445%7%48%
75250
TransparencyDay
38%6%11%24%17%3
74604
Night
37%5%11%24%19%4
75058
SeeingDay
17%10%26%25%16%5%
14401
Night
17%10%27%28%15%2
24367

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
18%7%35%433335%45%
1526
11th to 20thDay
19%8%35%5%3345%5%41%
1710
21st to endDay
15%9%26%5%33336%46%
1872
February1st to 10thDay
18%9%25%5%34346%41%
1642
11th to 20thDay
17%8%36%5%34346%41%
1748
21st to endDay
18%9%36%4345%5%6%37%
1480
March1st to 10thDay
18%7%25%424346%46%
1840
11th to 20thDay
21%8%36%5%33346%37%
1980
21st to endDay
20%9%36%5%35%45%6%33%
2286
April1st to 10thDay
12%5%35%5%3445%7%48%
2160
11th to 20thDay
17%6%36%6%3435%6%41%
2134
21st to endDay
19%6%36%425%45%6%41%
2160
May1st to 10thDay
16%6%38%6%3445%8%38%
2160
11th to 20thDay
15%5%245%35%47%7%42%
2367
21st to endDay
10%6%26%6%47%7%8%10%35%
2725
June1st to 10thDay
8%5%25%6%445%6%9%46%
2520
11th to 20thDay
5%3245%46%6%6%10%50%
2520
21st to endDay
5%3245%46%7%7%11%48%
2520
July1st to 10thDay
8%6%25%6%35%6%7%10%41%
2520
11th to 20thDay
5%3145%46%6%7%11%48%
2494
21st to endDay
6%425%6%5%6%7%7%10%43%
2546
August1st to 10thDay
7%425%6%46%7%8%11%42%
2274
11th to 20thDay
10%5%246%45%6%7%9%42%
2125
21st to endDay
8%425%6%46%6%5%9%47%
2376
September1st to 10thDay
10%424435%5%6%8%50%
2160
11th to 20thDay
11%5%245%3435%9%49%
2135
21st to endDay
11%424324447%55%
1980
October1st to 10thDay
10%424424347%56%
1805
11th to 20thDay
14%5%25%433345%53%
1800
21st to endDay
19%6%25%423345%47%
1980
November1st to 10thDay
13%424323346%56%
1697
11th to 20thDay
13%7%34333445%50%
1710
21st to endDay
20%7%25%323335%46%
1710
December1st to 10thDay
17%8%26%5%3445%5%41%
1528
11th to 20thDay
17%7%36%5%34446%40%
1918
21st to endDay
20%11%36%5%2345%6%34%
2783
January1st to 10thNight
18%6%35%42345%6%44%
2634
11th to 20thNight
19%7%3442445%6%43%
2470
21st to endNight
17%6%35%424446%45%
2711
February1st to 10thNight
18%9%45%423445%41%
2316
11th to 20thNight
17%7%45%434345%45%
2098
21st to endNight
20%7%25%42435%6%42%
1776
March1st to 10thNight
18%7%25%42434447%
2136
11th to 20thNight
20%7%35%5%35%35%5%40%
1980
21st to endNight
19%8%36%6%45%45%6%36%
2069
April1st to 10thNight
10%5%243346%6%7%51%
1800
11th to 20thNight
13%6%25%4345%6%7%45%
1775
21st to endNight
19%5%25%5%35%5%47%40%
1800
May1st to 10thNight
16%5%2432345%7%47%
1800
11th to 20thNight
15%6%25%5%2445%6%45%
1521
21st to endNight
10%5%36%5%35%5%7%8%41%
1551
June1st to 10thNight
9%424435%5%7%8%48%
1440
11th to 20thNight
5%31342446%9%60%
1440
21st to endNight
42144345%7%11%56%
1440
July1st to 10thNight
6%3245%346%7%10%50%
1440
11th to 20thNight
6%313325%5%6%11%55%
1461
21st to endNight
6%4144246%7%10%50%
1772
August1st to 10thNight
6%3235%45%6%7%9%49%
1662
11th to 20thNight
7%424435%36%9%54%
1776
21st to endNight
8%4245%245%6%9%51%
1980
September1st to 10thNight
10%42432336%7%55%
1800
11th to 20thNight
7%5%25%5%245%5%7%53%
1806
21st to endNight
9%323324447%57%
1980
October1st to 10thNight
7%3135%23447%62%
2150
11th to 20thNight
14%5%2432325%5%56%
2160
21st to endNight
19%6%2432333449%
2376
November1st to 10thNight
12%423322346%60%
2378
11th to 20thNight
15%5%2432335%6%53%
2470
21st to endNight
19%5%24423345%48%
2470
December1st to 10thNight
18%7%34334446%43%
2649
11th to 20thNight
17%7%345%34346%45%
3279
21st to endNight
19%9%37%5%3445%6%34%
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
43%39%26%14%4
1527
11th to 20thDay
45%5%10%25%14%1
1710
21st to endDay
42%312%24%16%3
1872
February1st to 10thDay
46%411%23%14%1
1642
11th to 20thDay
46%411%22%14%4
1758
21st to endDay
47%5%9%21%12%5%
1480
March1st to 10thDay
42%48%23%18%5%
1840
11th to 20thDay
50%5%10%17%15%3
1980
21st to endDay
51%6%11%19%10%1
2286
April1st to 10thDay
37%5%10%26%20%2
2160
11th to 20thDay
44%5%10%20%17%4
2134
21st to endDay
44%7%10%22%16%1
2160
May1st to 10thDay
45%8%11%21%14%1
2160
11th to 20thDay
40%8%13%21%16%2
2371
21st to endDay
41%11%15%21%11%2
2725
June1st to 10thDay
35%8%13%25%18%2
2520
11th to 20thDay
28%9%12%28%19%4
2520
21st to endDay
27%9%16%26%16%5%
2520
July1st to 10thDay
35%10%14%22%15%5%
2451
11th to 20thDay
28%8%16%26%18%4
2419
21st to endDay
33%10%13%30%12%2
2405
August1st to 10thDay
32%10%15%27%15%1
2260
11th to 20thDay
35%9%14%26%15%1
2125
21st to endDay
33%8%15%22%17%5%
2376
September1st to 10thDay
31%7%12%29%17%4
2160
11th to 20thDay
33%6%9%23%26%2
2135
21st to endDay
30%5%9%27%27%3
1980
October1st to 10thDay
28%7%10%25%26%5%
1805
11th to 20thDay
34%5%7%23%23%8%
1800
21st to endDay
40%46%25%19%5%
1980
November1st to 10thDay
31%410%25%22%7%
1697
11th to 20thDay
36%48%23%24%5%
1710
21st to endDay
43%38%25%20%2
1710
December1st to 10thDay
44%49%25%15%3
1528
11th to 20thDay
45%5%8%24%17%2
1915
21st to endDay
50%6%11%18%13%2
2783
January1st to 10thNight
41%410%24%19%2
2634
11th to 20thNight
43%410%25%16%2
2470
21st to endNight
41%5%10%26%16%2
2711
February1st to 10thNight
46%49%22%17%2
2316
11th to 20thNight
43%312%20%19%3
2099
21st to endNight
44%5%9%21%16%5%
1776
March1st to 10thNight
42%39%20%19%7%
2136
11th to 20thNight
47%5%11%19%15%3
1980
21st to endNight
49%6%10%22%11%1
2069
April1st to 10thNight
31%6%12%26%20%4
1800
11th to 20thNight
37%6%11%22%20%5%
1775
21st to endNight
44%6%9%23%17%2
1800
May1st to 10thNight
37%6%14%25%16%2
1800
11th to 20thNight
40%7%12%20%18%2
1522
21st to endNight
38%8%15%21%16%2
1552
June1st to 10thNight
31%8%14%23%22%2
1440
11th to 20thNight
19%8%13%33%21%6%
1440
21st to endNight
20%8%16%28%20%8%
1440
July1st to 10thNight
28%10%16%24%17%5%
1400
11th to 20thNight
23%8%17%27%18%6%
1413
21st to endNight
25%9%15%34%16%1
1673
August1st to 10thNight
28%10%17%30%15%2
1652
11th to 20thNight
28%6%13%29%21%3
1776
21st to endNight
27%7%15%27%18%6%
1980
September1st to 10thNight
28%7%9%32%19%6%
1800
11th to 20thNight
31%6%11%24%24%3
1806
21st to endNight
27%6%9%23%31%5%
1980
October1st to 10thNight
25%5%10%26%28%6%
2150
11th to 20thNight
31%38%24%26%7%
2160
21st to endNight
40%38%22%20%6%
2376
November1st to 10thNight
28%410%27%26%6%
2378
11th to 20thNight
33%38%24%24%7%
2470
21st to endNight
40%38%24%22%3
2470
December1st to 10thNight
42%5%10%23%17%2
2649
11th to 20thNight
42%49%25%19%2
3281
21st to endNight
49%6%12%18%13%2
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
30%17%34%16%2
270
11th to 20thDay
31%22%32%13%
270
21st to endDay
22%23%40%12%3
294
February1st to 10thDay
30%23%34%10%3
240
11th to 20thDay
32%28%28%11%1
240
21st to endDay
34%23%33%8%2
198
March1st to 10thDay
28%23%33%13%3
240
11th to 20thDay
35%21%29%11%3
240
21st to endDay
30%18%33%14%41
372
April1st to 10thDay
21%17%34%21%7%
420
11th to 20thDay
27%17%28%19%8%1
412
21st to endDay
23%15%34%21%6%2
420
May1st to 10thDay
20%16%34%21%8%1
423
11th to 20thDay
20%10%28%25%13%4
525
21st to endDay
11%7%32%30%15%5%
679
June1st to 10thDay
12%5%23%27%24%8%
630
11th to 20thDay
5%324%41%21%6%
630
21st to endDay
6%5%30%34%18%7%
630
July1st to 10thDay
10%214%28%32%14%
621
11th to 20thDay
6%219%33%30%10%
618
21st to endDay
8%315%36%29%10%
684
August1st to 10thDay
8%114%39%29%10%
572
11th to 20thDay
14%217%29%29%8%
439
21st to endDay
11%114%27%32%15%
495
September1st to 10thDay
8%313%37%30%9%
450
11th to 20thDay
9%415%29%29%14%
450
21st to endDay
13%8%20%31%20%8%
450
October1st to 10thDay
13%9%25%37%11%5%
275
11th to 20thDay
22%11%36%22%8%
270
21st to endDay
29%16%31%18%6%
297
November1st to 10thDay
19%14%34%23%10%1
270
11th to 20thDay
23%15%30%22%9%1
270
21st to endDay
31%14%28%18%8%1
270
December1st to 10thDay
22%19%33%15%9%2
270
11th to 20thDay
27%19%29%19%5%
270
21st to endDay
32%21%31%12%4
297
January1st to 10thNight
24%17%34%21%4
950
11th to 20thNight
25%20%32%19%3
950
21st to endNight
22%14%38%25%1
1043
February1st to 10thNight
24%16%36%21%3
876
11th to 20thNight
24%19%37%18%2
703
21st to endNight
25%19%35%18%3
592
March1st to 10thNight
24%14%35%25%2
696
11th to 20thNight
23%13%32%29%4
540
21st to endNight
26%10%34%24%6%
594
April1st to 10thNight
13%16%38%27%6%
540
11th to 20thNight
17%15%29%27%11%1
533
21st to endNight
18%13%35%25%9%
540
May1st to 10thNight
18%8%32%29%12%1
540
11th to 20thNight
19%5%29%30%15%3
531
21st to endNight
12%424%33%22%4
584
June1st to 10thNight
9%417%35%31%4
540
11th to 20thNight
4119%46%27%3
540
21st to endNight
4222%38%31%3
540
July1st to 10thNight
7%111%31%41%9%
525
11th to 20thNight
7%110%39%37%6%
522
21st to endNight
7%212%35%38%6%
591
August1st to 10thNight
6%211%37%39%5%
537
11th to 20thNight
8%112%33%41%5%
534
21st to endNight
7%111%32%41%7%
594
September1st to 10thNight
12%211%33%39%4
540
11th to 20thNight
9%214%30%37%8%
546
21st to endNight
10%5%22%29%29%5%
720
October1st to 10thNight
8%7%20%36%25%4
720
11th to 20thNight
16%9%30%29%15%1
720
21st to endNight
23%11%29%26%10%1
792
November1st to 10thNight
14%9%33%29%13%1
740
11th to 20thNight
18%11%31%31%9%
760
21st to endNight
24%11%30%26%9%1
760
December1st to 10thNight
23%13%29%29%6%
939
11th to 20thNight
26%11%29%28%6%
950
21st to endNight
27%14%31%24%4
1045
Page generated at 2024-01-28 04:26:31. Version ac07

Copyright 2024 Attilla Danko


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