Rose Hill Plantation State Historic Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rose Hill Plantation State Historic Site clear sky chart from 2005-11-05 to 2019-06-02.

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
47%
18036
22%
53816
15%
17997
55%
17997
27%
34025

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
31%
838
24%
2717
11%
836
47%
836
21%
1658
January16th to endNight
31%
896
25%
2912
14%
896
46%
896
24%
1751
February1st to 15thNight
32%
822
23%
2577
12%
821
45%
821
25%
1581
February16th to endNight
28%
735
24%
2195
10%
735
42%
735
24%
1403
March1st to 15thNight
32%
840
26%
2310
13%
840
42%
840
28%
1466
March16th to endNight
35%
896
21%
2464
10%
896
44%
896
27%
1599
April1st to 15thNight
40%
838
23%
2275
12%
838
49%
838
32%
1391
April16th to endNight
44%
702
25%
1948
13%
702
53%
702
32%
1194
May1st to 15thNight
49%
630
19%
1890
11%
630
54%
630
28%
1185
May16th to endNight
59%
657
18%
1971
13%
657
62%
657
25%
1297
June1st to 15thNight
64%
588
15%
1765
13%
588
66%
588
26%
1175
June16th to endNight
65%
585
14%
1755
11%
585
66%
585
26%
1149
July1st to 15thNight
66%
555
10%
1665
9%
555
66%
555
22%
1179
July16th to endNight
65%
612
13%
1739
10%
579
67%
579
25%
1185
August1st to 15thNight
65%
575
15%
1715
12%
572
66%
572
23%
1188
August16th to endNight
65%
702
15%
1983
13%
702
66%
702
24%
1392
September1st to 15thNight
64%
780
18%
2145
15%
780
65%
780
29%
1421
September16th to endNight
57%
777
20%
2145
16%
777
61%
777
27%
1450
October1st to 15thNight
54%
780
28%
2260
25%
780
61%
780
32%
1383
October16th to endNight
53%
832
34%
2496
25%
832
66%
832
38%
1373
November1st to 15thNight
52%
820
29%
2517
23%
820
61%
820
33%
1454
November16th to endNight
48%
840
27%
2730
21%
840
58%
840
30%
1552
December1st to 15thNight
39%
840
24%
2730
16%
840
51%
840
23%
1711
December16th to endNight
36%
896
22%
2912
16%
896
44%
896
21%
1888

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%5%245%3445%7%43%
54516
Night
13%5%2442445%7%44%
54014
TransparencyDay
39%7%11%20%17%4
54217
Night
37%6%11%18%19%6%
53817
SeeingDay
17%6%21%23%20%10%
7829
Night
16%7%21%30%21%3
18042

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 15thDay
17%7%23424335%44%
1881
16th to endDay
15%6%2442334449%
2016
February1st to 15thDay
15%6%24433446%45%
1941
16th to endDay
19%6%24324345%44%
1850
March1st to 15thDay
16%424423335%48%
2310
16th to endDay
14%5%245%25%345%44%
2463
April1st to 15thDay
11%42343445%8%46%
2333
16th to endDay
12%4235%3435%6%47%
2628
May1st to 15thDay
11%424435%6%7%7%42%
2721
16th to endDay
10%5%25%5%35%45%8%41%
2847
June1st to 15thDay
8%425%5%36%6%7%10%38%
2548
16th to endDay
5%3135%37%7%8%11%41%
2535
July1st to 15thDay
9%5%36%6%46%6%7%10%33%
2535
16th to endDay
6%5%26%7%47%6%8%10%33%
2673
August1st to 15thDay
14%5%26%7%36%6%8%10%29%
2487
16th to endDay
11%5%26%5%46%6%7%9%32%
2555
September1st to 15thDay
10%426%5%35%5%7%9%39%
2145
16th to endDay
16%6%25%5%34445%41%
2145
October1st to 15thDay
15%5%1331233454%
2028
16th to endDay
11%32332232459%
2080
November1st to 15thDay
16%413213245%52%
1999
16th to endDay
14%423423335%51%
1890
December1st to 15thDay
18%7%24333335%42%
1890
16th to endDay
22%6%24423345%40%
2016
January1st to 15thNight
17%5%2332344447%
2717
16th to endNight
17%5%33323335%48%
2912
February1st to 15thNight
15%414423445%47%
2568
16th to endNight
17%5%14434446%43%
2195
March1st to 15thNight
15%424433346%46%
2310
16th to endNight
12%5%35%4245%5%5%45%
2464
April1st to 15thNight
13%414423349%48%
2275
16th to endNight
11%434424446%50%
1948
May1st to 15thNight
8%5%25%6%3446%9%43%
1889
16th to endNight
10%414437%5%7%9%40%
1970
June1st to 15thNight
10%425%5%35%6%9%10%36%
1765
16th to endNight
5%5%16%6%45%7%7%10%38%
1755
July1st to 15thNight
7%5%35%7%37%7%8%11%30%
1755
16th to endNight
6%425%7%36%6%8%13%33%
1847
August1st to 15thNight
11%426%6%35%6%8%12%30%
1726
16th to endNight
10%5%25%6%45%6%8%10%33%
1983
September1st to 15thNight
10%425%6%345%7%9%40%
2145
16th to endNight
14%6%2443445%6%42%
2145
October1st to 15thNight
16%41332234451%
2260
16th to endNight
10%41432233459%
2496
November1st to 15thNight
15%413313336%54%
2517
16th to endNight
13%423423346%51%
2730
December1st to 15thNight
17%6%24413345%45%
2730
16th to endNight
21%5%25%324346%40%
2912

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
43%47%16%22%5%
1882
16th to endDay
38%36%20%22%8%
2016
February1st to 15thDay
39%49%20%21%4
1943
16th to endDay
42%36%21%19%5%
1850
March1st to 15thDay
38%36%21%21%8%
2310
16th to endDay
41%5%10%21%18%3
2464
April1st to 15thDay
35%5%10%21%22%5%
2333
16th to endDay
35%6%10%19%19%8%
2628
May1st to 15thDay
36%8%14%19%17%2
2721
16th to endDay
38%9%12%23%14%1
2851
June1st to 15thDay
37%10%16%24%9%1
2548
16th to endDay
32%11%16%22%13%1
2535
July1st to 15thDay
41%11%17%16%10%2
2396
16th to endDay
39%11%18%19%8%2
2518
August1st to 15thDay
45%10%15%16%10%1
2474
16th to endDay
43%11%16%16%9%1
2555
September1st to 15thDay
38%9%14%17%17%2
2145
16th to endDay
44%6%9%18%17%4
2145
October1st to 15thDay
34%49%21%24%5%
2028
16th to endDay
30%36%20%28%11%
2080
November1st to 15thDay
35%37%18%26%8%
1999
16th to endDay
35%38%20%24%7%
1890
December1st to 15thDay
44%47%20%17%5%
1890
16th to endDay
46%48%20%15%5%
2016
January1st to 15thNight
39%47%16%24%7%
2717
16th to endNight
39%25%19%23%8%
2912
February1st to 15thNight
39%48%20%22%6%
2577
16th to endNight
40%49%19%20%5%
2195
March1st to 15thNight
38%49%17%21%9%
2310
16th to endNight
38%5%10%17%22%4
2464
April1st to 15thNight
33%410%21%23%6%
2275
16th to endNight
34%49%20%20%9%
1948
May1st to 15thNight
35%8%14%20%17%3
1890
16th to endNight
36%12%10%22%15%3
1972
June1st to 15thNight
37%11%17%22%9%1
1765
16th to endNight
36%11%15%20%13%2
1755
July1st to 15thNight
40%14%19%14%7%3
1665
16th to endNight
38%12%21%17%8%2
1739
August1st to 15thNight
41%11%19%17%9%
1715
16th to endNight
40%12%18%16%10%1
1983
September1st to 15thNight
37%9%17%16%14%4
2145
16th to endNight
41%7%11%17%17%4
2145
October1st to 15thNight
35%5%9%19%23%7%
2260
16th to endNight
29%35%20%28%12%
2496
November1st to 15thNight
33%36%17%26%11%
2517
16th to endNight
34%36%19%26%9%
2730
December1st to 15thNight
41%48%19%18%7%
2730
16th to endNight
44%49%17%18%5%
2912

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
26%13%36%18%4
180
16th to endDay
22%18%35%17%6%
192
February1st to 15thDay
20%22%39%12%4
180
16th to endDay
28%11%39%16%3
169
March1st to 15thDay
20%15%35%21%6%
390
16th to endDay
17%12%38%20%9%1
416
April1st to 15thDay
18%12%31%21%15%1
390
16th to endDay
16%7%24%26%18%6%
379
May1st to 15thDay
11%8%26%24%20%9%
408
16th to endDay
18%414%22%23%17%
459
June1st to 15thDay
9%112%23%34%17%
379
16th to endDay
8%114%26%27%21%
375
July1st to 15thDay
9%110%22%33%22%
365
16th to endDay
7%17%32%32%17%
390
August1st to 15thDay
18%29%18%31%19%
358
16th to endDay
14%10%25%26%22%
396
September1st to 15thDay
14%112%21%30%20%
375
16th to endDay
22%213%22%27%11%
374
October1st to 15thDay
20%217%29%21%9%
375
16th to endDay
13%6%23%24%26%6%
400
November1st to 15thDay
26%7%18%26%16%4
327
16th to endDay
7%9%33%28%16%4
180
December1st to 15thDay
30%10%33%17%8%
180
16th to endDay
31%8%36%17%5%
192
January1st to 15thNight
21%16%25%28%7%
840
16th to endNight
20%14%29%30%4
896
February1st to 15thNight
18%13%32%32%3
824
16th to endNight
19%14%32%29%3
735
March1st to 15thNight
17%12%33%29%7%
840
16th to endNight
15%12%30%30%11%
896
April1st to 15thNight
15%11%28%30%13%
838
16th to endNight
13%7%26%33%17%
702
May1st to 15thNight
11%425%35%21%1
630
16th to endNight
13%114%30%35%4
659
June1st to 15thNight
12%18%36%31%8%
588
16th to endNight
9%11%28%40%10%
585
July1st to 15thNight
10%9%31%36%10%
555
16th to endNight
9%9%26%44%8%
612
August1st to 15thNight
14%7%24%42%9%
575
16th to endNight
13%9%26%43%7%
702
September1st to 15thNight
12%19%28%39%8%
780
16th to endNight
18%114%26%34%4
777
October1st to 15thNight
18%418%22%30%6%
780
16th to endNight
12%6%23%30%23%3
832
November1st to 15thNight
17%5%19%35%18%2
820
16th to endNight
14%10%22%33%17%1
840
December1st to 15thNight
21%10%22%32%12%
840
16th to endNight
24%9%25%32%8%
896
Page generated at 2019-06-02 19:43:08. Version ac04

Copyright 2019 A. Danko


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