River Valley RV Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the River Valley RV Park clear sky chart from 2005-11-05 to 2017-12-02.

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
32%
16145
14%
47868
8%
16103
39%
16103
19%
33628

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
15%
900
8%
2506
2%
895
20%
895
9%
2055
January16th to endNight
16%
960
7%
2688
1%
960
21%
960
10%
2172
February1st to 15thNight
17%
701
10%
2244
3%
701
24%
701
10%
1722
February16th to endNight
20%
631
12%
1893
4%
631
28%
631
12%
1460
March1st to 15thNight
26%
720
15%
2112
8%
720
32%
720
18%
1486
March16th to endNight
28%
762
17%
2106
9%
762
35%
762
21%
1460
April1st to 15thNight
27%
539
15%
1780
8%
539
36%
539
18%
1219
April16th to endNight
34%
540
20%
1620
9%
540
43%
540
24%
1072
May1st to 15thNight
35%
540
15%
1620
8%
540
42%
540
23%
1103
May16th to endNight
42%
562
16%
1563
9%
561
51%
561
29%
1000
June1st to 15thNight
43%
444
15%
1344
11%
444
48%
444
26%
849
June16th to endNight
49%
459
15%
1359
9%
459
55%
459
31%
857
July1st to 15thNight
63%
510
16%
1360
12%
510
66%
510
43%
784
July16th to endNight
58%
564
17%
1417
11%
531
62%
531
38%
857
August1st to 15thNight
61%
539
20%
1607
14%
536
67%
536
38%
907
August16th to endNight
59%
573
22%
1767
17%
573
65%
573
36%
1018
September1st to 15thNight
53%
630
23%
1890
17%
630
59%
630
36%
1077
September16th to endNight
51%
717
24%
1980
18%
717
56%
717
32%
1230
October1st to 15thNight
39%
720
18%
2046
13%
720
46%
720
25%
1378
October16th to endNight
23%
768
13%
2467
8%
768
32%
768
14%
1780
November1st to 15thNight
28%
760
17%
2471
13%
760
36%
760
18%
1698
November16th to endNight
21%
780
10%
2584
5%
780
27%
780
11%
1967
December1st to 15thNight
13%
866
6%
2684
2%
866
18%
866
9%
2188
December16th to endNight
15%
960
8%
2760
1%
960
21%
960
9%
2289

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%8%47%6%35%5%5%7%32%
48567
Night
14%8%46%5%3445%7%34%
48037
Cloud CoverDay
13%8%46%6%35%5%5%7%33%
48576
Night
14%8%46%5%3445%7%34%
48042
TransparencyDay
49%6%12%19%10%1
48254
Night
48%6%12%20%10%1
47868
SeeingDay
18%12%30%21%11%5%
6207
Night
19%11%30%26%10%1
16149

By Month

Percentage Cloud Cover NE (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
16%13%7%10%9%5%6%5%45%15%
1432
16th to endDay
13%16%10%11%10%47%5%25%12%
1536
February1st to 15thDay
13%13%6%10%10%5%6%45%6%18%
1615
16th to endDay
12%12%7%10%10%36%5%5%6%19%
1580
March1st to 15thDay
14%9%47%7%45%45%7%29%
1837
16th to endDay
14%9%5%7%6%34446%32%
2129
April1st to 15thDay
19%12%46%423336%32%
2167
16th to endDay
16%7%25%6%3445%6%35%
2340
May1st to 15thDay
19%6%36%5%35%46%6%34%
2331
16th to endDay
11%5%35%5%35%45%8%41%
2550
June1st to 15thDay
12%6%35%5%245%6%7%38%
2610
16th to endDay
10%5%35%5%36%6%6%8%38%
2594
July1st to 15thDay
6%4146%46%6%6%9%44%
2520
16th to endDay
8%425%6%35%6%7%9%40%
2655
August1st to 15thDay
7%5%26%6%36%6%6%9%39%
2343
16th to endDay
12%6%25%43445%8%41%
2432
September1st to 15thDay
12%4145%35%45%8%43%
2058
16th to endDay
11%436%5%35%5%5%9%40%
1980
October1st to 15thDay
17%8%36%6%34345%36%
1914
16th to endDay
21%10%47%6%35%45%7%23%
1755
November1st to 15thDay
15%10%47%5%33447%32%
1717
16th to endDay
19%16%49%7%3444421%
1703
December1st to 15thDay
18%12%6%11%8%35%445%18%
1310
16th to endDay
21%17%8%9%6%34345%15%
1459
January1st to 15thNight
19%12%5%10%8%35%35%419%
2506
16th to endNight
12%13%7%10%7%46%6%6%6%18%
2688
February1st to 15thNight
12%11%6%8%8%46%5%5%5%25%
2242
16th to endNight
14%12%5%9%8%35%446%24%
1893
March1st to 15thNight
15%7%37%5%34446%36%
2099
16th to endNight
14%7%46%5%24447%38%
2106
April1st to 15thNight
18%9%35%425%348%33%
1780
16th to endNight
17%8%24323347%40%
1620
May1st to 15thNight
13%6%25%6%35%5%5%8%37%
1620
16th to endNight
11%5%15%43445%9%43%
1561
June1st to 15thNight
12%4334245%6%7%43%
1344
16th to endNight
7%5%25%425%47%8%45%
1359
July1st to 15thNight
5%3143245%5%9%54%
1440
16th to endNight
6%324315%46%9%50%
1513
August1st to 15thNight
5%31342446%9%52%
1617
16th to endNight
9%32432245%7%53%
1767
September1st to 15thNight
11%31432335%6%54%
1890
16th to endNight
8%425%5%24447%48%
1980
October1st to 15thNight
17%6%25%433346%41%
2046
16th to endNight
21%8%36%5%35%346%31%
2467
November1st to 15thNight
14%8%36%5%245%5%7%35%
2471
16th to endNight
18%12%47%6%35%46%6%23%
2584
December1st to 15thNight
19%14%6%9%6%34446%19%
2684
16th to endNight
21%13%6%9%6%35%45%6%16%
2760

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
16%13%6%11%8%6%6%445%16%
1432
16th to endDay
13%15%10%11%9%5%7%435%12%
1536
February1st to 15thDay
13%13%5%10%9%5%6%446%19%
1615
16th to endDay
11%13%6%10%9%46%5%5%5%20%
1580
March1st to 15thDay
14%8%5%7%7%45%5%5%6%29%
1847
16th to endDay
14%9%47%6%35%445%32%
2128
April1st to 15thDay
19%12%36%433345%32%
2167
16th to endDay
16%7%25%6%35%45%6%35%
2340
May1st to 15thDay
19%6%35%5%345%6%6%34%
2331
16th to endDay
11%5%25%5%35%45%8%41%
2550
June1st to 15thDay
12%5%35%5%346%6%7%38%
2610
16th to endDay
10%5%25%5%36%6%6%8%38%
2594
July1st to 15thDay
6%425%5%46%5%6%9%44%
2520
16th to endDay
8%425%6%36%6%6%9%40%
2655
August1st to 15thDay
7%5%26%6%45%6%6%9%39%
2343
16th to endDay
12%6%35%43445%8%41%
2432
September1st to 15thDay
12%4235%345%48%43%
2058
16th to endDay
12%425%6%345%5%9%40%
1980
October1st to 15thDay
17%7%37%6%24345%36%
1914
16th to endDay
21%10%46%6%34447%24%
1755
November1st to 15thDay
15%10%5%7%5%3345%7%32%
1717
16th to endDay
18%16%5%8%8%35%44421%
1703
December1st to 15thDay
19%12%6%11%8%43446%18%
1310
16th to endDay
21%16%8%9%6%34436%14%
1459
January1st to 15thNight
20%12%5%10%8%4444420%
2506
16th to endNight
12%12%7%10%7%37%6%5%7%18%
2688
February1st to 15thNight
12%11%6%8%8%45%5%5%5%25%
2235
16th to endNight
15%12%49%8%36%446%24%
1893
March1st to 15thNight
15%8%47%6%34345%36%
2112
16th to endNight
14%7%46%5%23447%38%
2106
April1st to 15thNight
19%9%36%424448%33%
1780
16th to endNight
17%8%25%323447%40%
1620
May1st to 15thNight
14%6%25%5%35%45%8%38%
1619
16th to endNight
11%5%245%2446%9%43%
1561
June1st to 15thNight
13%5%234245%5%7%43%
1344
16th to endNight
7%5%25%4245%6%8%45%
1359
July1st to 15thNight
5%3144245%5%9%54%
1440
16th to endNight
5%424325%46%8%51%
1513
August1st to 15thNight
5%41343446%9%52%
1617
16th to endNight
9%41431435%7%53%
1767
September1st to 15thNight
11%31441335%6%54%
1890
16th to endNight
8%5%25%43445%7%48%
1980
October1st to 15thNight
17%7%25%5%23445%41%
2046
16th to endNight
21%8%36%5%35%446%30%
2467
November1st to 15thNight
14%8%36%6%2445%6%35%
2471
16th to endNight
18%13%5%6%6%3445%7%22%
2584
December1st to 15thNight
19%14%7%8%6%35%445%20%
2684
16th to endNight
21%13%6%10%6%35%45%6%16%
2760

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
70%6%8%11%2
1433
16th to endDay
75%5%7%8%3
1536
February1st to 15thDay
65%5%9%14%4
1617
16th to endDay
63%6%10%12%5%1
1580
March1st to 15thDay
53%6%11%18%8%
1847
16th to endDay
52%6%12%19%8%1
2129
April1st to 15thDay
53%49%19%11%
2167
16th to endDay
48%5%13%14%15%2
2340
May1st to 15thDay
48%6%11%20%10%2
2331
16th to endDay
40%7%13%25%13%
2554
June1st to 15thDay
42%7%12%23%12%
2610
16th to endDay
40%8%13%21%13%
2594
July1st to 15thDay
34%7%12%26%17%1
2371
16th to endDay
37%9%13%21%15%2
2488
August1st to 15thDay
38%8%13%24%13%1
2329
16th to endDay
39%6%13%23%14%2
2432
September1st to 15thDay
37%7%11%29%12%1
2058
16th to endDay
39%7%16%25%10%
1980
October1st to 15thDay
49%6%10%22%10%
1914
16th to endDay
59%6%14%13%5%
1755
November1st to 15thDay
51%6%13%19%7%
1717
16th to endDay
65%6%11%11%5%
1703
December1st to 15thDay
67%6%11%11%2
1310
16th to endDay
71%6%10%8%2
1459
January1st to 15thNight
66%49%12%5%
2506
16th to endNight
62%7%14%11%3
2688
February1st to 15thNight
58%7%9%16%6%
2244
16th to endNight
60%412%14%7%
1893
March1st to 15thNight
50%5%12%19%10%1
2112
16th to endNight
45%6%13%20%12%1
2106
April1st to 15thNight
50%310%19%14%
1780
16th to endNight
43%5%10%20%16%3
1620
May1st to 15thNight
44%5%11%22%13%2
1620
16th to endNight
36%7%12%26%14%3
1563
June1st to 15thNight
37%7%11%24%17%
1344
16th to endNight
34%7%13%25%17%
1359
July1st to 15thNight
25%6%13%30%21%2
1360
16th to endNight
29%7%16%28%16%2
1417
August1st to 15thNight
27%6%16%32%15%
1607
16th to endNight
29%6%13%28%19%1
1767
September1st to 15thNight
30%5%12%32%18%
1890
16th to endNight
34%7%13%33%10%
1980
October1st to 15thNight
44%5%11%25%12%1
2046
16th to endNight
54%5%12%20%7%
2467
November1st to 15thNight
47%7%14%20%10%
2471
16th to endNight
59%6%14%13%4
2584
December1st to 15thNight
66%5%10%11%5%
2684
16th to endNight
67%5%11%11%3
2760

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
24%21%43%8%2
90
16th to endDay
33%12%40%11%2
96
February1st to 15thDay
25%28%38%6%
90
16th to endDay
29%20%33%11%4
81
March1st to 15thDay
26%18%36%15%3
137
16th to endDay
27%9%30%21%9%2
288
April1st to 15thDay
30%11%25%21%10%1
270
16th to endDay
22%13%31%18%10%4
270
May1st to 15thDay
25%13%29%18%7%5%
288
16th to endDay
16%15%31%21%10%4
450
June1st to 15thDay
13%14%33%25%9%3
495
16th to endDay
12%13%37%20%11%4
495
July1st to 15thDay
7%7%33%26%17%7%
475
16th to endDay
9%8%30%28%14%7%
515
August1st to 15thDay
7%324%30%18%15%
316
16th to endDay
15%7%20%25%18%12%
332
September1st to 15thDay
12%6%24%24%20%12%
315
16th to endDay
16%6%21%24%24%7%
314
October1st to 15thDay
23%11%26%25%10%2
315
16th to endDay
30%14%40%11%2
171
November1st to 15thDay
24%14%38%13%8%
135
16th to endDay
28%23%35%7%4
123
December1st to 15thDay
33%30%25%11%
63
16th to endDay
39%30%27%2
83
January1st to 15thNight
27%17%31%17%5%
900
16th to endNight
19%14%38%22%5%
960
February1st to 15thNight
19%19%35%21%4
704
16th to endNight
25%15%30%23%4
631
March1st to 15thNight
19%16%31%25%6%
720
16th to endNight
17%15%33%25%6%1
762
April1st to 15thNight
21%11%34%25%5%
539
16th to endNight
22%9%31%27%7%1
540
May1st to 15thNight
17%8%33%30%9%1
540
16th to endNight
14%8%28%31%14%1
563
June1st to 15thNight
14%8%27%34%14%
444
16th to endNight
10%428%38%15%1
459
July1st to 15thNight
9%220%42%22%3
510
16th to endNight
7%125%40%23%1
564
August1st to 15thNight
8%21%40%26%2
539
16th to endNight
10%320%36%26%2
573
September1st to 15thNight
13%424%29%21%5%
630
16th to endNight
12%6%24%29%23%4
717
October1st to 15thNight
20%7%27%30%12%1
720
16th to endNight
26%14%31%20%5%
768
November1st to 15thNight
20%13%33%23%9%
760
16th to endNight
26%16%30%21%6%
780
December1st to 15thNight
26%16%33%20%3
866
16th to endNight
28%15%33%19%3
960
Page generated at 2017-12-03 11:16:35. Version ac04

Copyright 2017 A. Danko


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