Rusty's RV Ranch
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rusty's RV Ranch clear sky chart from 2005-11-05 to 2018-10-08.

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
69%
16732
34%
51030
27%
16690
77%
16690
49%
24933

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
68%
779
34%
2522
32%
776
75%
776
48%
1200
January16th to endNight
65%
832
37%
2704
33%
832
75%
832
47%
1280
February1st to 15thNight
67%
759
36%
2472
31%
756
79%
756
55%
1066
February16th to endNight
55%
684
42%
1895
28%
684
69%
684
54%
935
March1st to 15thNight
59%
780
40%
2145
26%
780
71%
780
58%
1037
March16th to endNight
65%
832
39%
2288
23%
832
77%
832
60%
1067
April1st to 15thNight
56%
663
38%
2027
22%
663
74%
663
56%
905
April16th to endNight
57%
579
43%
1929
28%
579
78%
579
63%
740
May1st to 15thNight
59%
584
37%
1888
27%
584
72%
584
61%
765
May16th to endNight
65%
609
39%
1828
29%
609
75%
609
61%
792
June1st to 15thNight
77%
585
34%
1755
29%
585
80%
585
63%
762
June16th to endNight
80%
585
25%
1755
23%
585
81%
585
48%
874
July1st to 15thNight
76%
555
16%
1665
14%
555
77%
555
28%
1053
July16th to endNight
78%
612
11%
1737
10%
579
78%
579
20%
1205
August1st to 15thNight
78%
575
19%
1751
19%
572
78%
572
27%
1102
August16th to endNight
79%
621
21%
2070
23%
621
79%
621
26%
1271
September1st to 15thNight
75%
650
25%
2015
24%
650
76%
650
30%
1230
September16th to endNight
77%
776
37%
2145
27%
776
82%
776
55%
1096
October1st to 15thNight
76%
752
36%
2256
28%
752
81%
752
58%
1035
October16th to endNight
83%
768
43%
2304
35%
768
87%
768
68%
970
November1st to 15thNight
74%
760
42%
2280
32%
760
82%
760
66%
968
November16th to endNight
67%
780
44%
2360
34%
780
76%
780
54%
1103
December1st to 15thNight
67%
780
38%
2535
32%
780
75%
780
48%
1182
December16th to endNight
62%
832
37%
2704
33%
832
71%
832
46%
1295

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
221232345%7%63%
52086
Night
221232345%6%66%
51237
TransparencyDay
20%5%7%14%26%25%
51781
Night
18%5%7%15%28%24%
51043
SeeingDay
6%10%20%31%23%7%
6623
Night
3417%38%31%4
16741

By Month

Percentage Cloud Cover SW (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
221232346%6%64%
1746
16th to endDay
4323212245%65%
1872
February1st to 15thDay
222213345%70%
1710
16th to endDay
231122235%6%68%
1859
March1st to 15thDay
112323447%68%
2145
16th to endDay
112212246%73%
2288
April1st to 15thDay
111112246%76%
2249
16th to endDay
11111113382%
2306
May1st to 15thDay
11213235%76%
2389
16th to endDay
111212335%77%
2637
June1st to 15thDay
1111212447%72%
2535
16th to endDay
2212424347%63%
2535
July1st to 15thDay
5%2145%48%7%9%10%40%
2535
16th to endDay
6%425%6%5%7%8%9%11%31%
2675
August1st to 15thDay
5%4146%48%8%9%11%35%
2450
16th to endDay
5%4245%36%7%9%10%39%
2484
September1st to 15thDay
6%3246%35%6%7%7%46%
2271
16th to endDay
4213313346%65%
2144
October1st to 15thDay
112312335%72%
1873
16th to endDay
11122223477%
1920
November1st to 15thDay
111212235%77%
1909
16th to endDay
221221233472%
1927
December1st to 15thDay
3112323346%67%
1755
16th to endDay
1312313336%67%
1872
January1st to 15thNight
32231235%5%67%
2522
16th to endNight
3211323345%68%
2704
February1st to 15thNight
112223245%73%
2472
16th to endNight
111213346%71%
1895
March1st to 15thNight
21221235%6%72%
2145
16th to endNight
111213235%76%
2288
April1st to 15thNight
112213446%72%
2027
16th to endNight
11111235%81%
1929
May1st to 15thNight
121223478%
1888
16th to endNight
21121323478%
1828
June1st to 15thNight
211111224475%
1755
16th to endNight
2123245%7%7%62%
1755
July1st to 15thNight
2225%6%48%8%9%10%40%
1755
16th to endNight
3325%6%5%9%10%12%14%27%
1845
August1st to 15thNight
23246%46%7%9%11%41%
1760
16th to endNight
43145%46%7%8%10%41%
2070
September1st to 15thNight
6%414435%7%7%10%44%
2015
16th to endNight
321322234470%
2145
October1st to 15thNight
1112212335%74%
2256
16th to endNight
111134479%
2304
November1st to 15thNight
111211235%78%
2280
16th to endNight
2212212236%72%
2360
December1st to 15thNight
222312346%68%
2535
16th to endNight
221321335%5%67%
2704

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
18%5%7%16%34%16%
1747
16th to endDay
22%4415%33%20%
1872
February1st to 15thDay
17%3414%31%28%
1710
16th to endDay
17%35%14%30%27%
1859
March1st to 15thDay
16%3412%34%29%
2145
16th to endDay
13%25%11%36%30%
2288
April1st to 15thDay
11%2310%38%33%
2249
16th to endDay
9%129%28%48%
2306
May1st to 15thDay
12%248%28%43%
2389
16th to endDay
11%248%26%46%
2640
June1st to 15thDay
13%345%23%50%
2535
16th to endDay
20%46%9%21%37%
2535
July1st to 15thDay
32%11%15%16%13%10%
2396
16th to endDay
39%14%18%18%7%
2520
August1st to 15thDay
36%12%14%19%12%3
2435
16th to endDay
35%11%13%16%14%8%
2484
September1st to 15thDay
33%8%11%16%18%11%
2271
16th to endDay
20%35%18%33%19%
2144
October1st to 15thDay
15%26%16%29%29%
1873
16th to endDay
12%2417%32%30%
1920
November1st to 15thDay
11%3420%35%24%
1909
16th to endDay
17%3315%33%26%
1927
December1st to 15thDay
20%35%21%33%15%
1755
16th to endDay
21%38%21%31%12%
1872
January1st to 15thNight
19%46%17%33%18%
2522
16th to endNight
20%35%18%33%18%
2704
February1st to 15thNight
15%25%16%31%28%
2483
16th to endNight
15%45%14%33%26%
1895
March1st to 15thNight
15%2413%32%30%
2145
16th to endNight
13%2411%39%27%
2288
April1st to 15thNight
14%2412%35%30%
2027
16th to endNight
10%139%31%44%
1929
May1st to 15thNight
10%338%29%44%
1889
16th to endNight
12%2311%28%41%
1829
June1st to 15thNight
12%247%23%48%
1755
16th to endNight
19%5%7%10%19%36%
1755
July1st to 15thNight
32%13%15%17%12%8%
1665
16th to endNight
38%16%22%16%4
1737
August1st to 15thNight
33%12%17%19%14%2
1751
16th to endNight
33%11%16%17%13%8%
2070
September1st to 15thNight
31%10%12%18%16%10%
2015
16th to endNight
18%4417%37%17%
2145
October1st to 15thNight
14%38%16%27%30%
2256
16th to endNight
10%2416%29%36%
2304
November1st to 15thNight
10%25%21%34%25%
2280
16th to endNight
17%3313%32%29%
2360
December1st to 15thNight
18%46%21%32%16%
2535
16th to endNight
19%48%20%32%13%
2704

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
8%9%25%38%15%2
135
16th to endDay
6%9%19%39%18%6%
144
February1st to 15thDay
10%5%16%32%28%5%
135
16th to endDay
14%26%29%19%10%
278
March1st to 15thDay
420%32%28%10%3
330
16th to endDay
7%22%30%24%11%3
352
April1st to 15thDay
5%20%32%26%11%3
329
16th to endDay
423%35%27%7%1
318
May1st to 15thDay
6%23%34%22%9%2
348
16th to endDay
311%36%35%10%1
394
June1st to 15thDay
4428%38%18%5%
375
16th to endDay
5%112%41%32%6%
375
July1st to 15thDay
6%8%37%39%7%
365
16th to endDay
6%15%28%37%19%
391
August1st to 15thDay
7%16%27%38%19%
359
16th to endDay
6%426%41%19%
396
September1st to 15thDay
9%18%37%33%9%
375
16th to endDay
7%6%17%32%27%8%
374
October1st to 15thDay
5%5%17%35%25%12%
157
16th to endDay
2218%27%36%13%
144
November1st to 15thDay
6%8%25%28%24%5%
135
16th to endDay
5%14%17%34%22%4
135
December1st to 15thDay
9%10%20%28%24%6%
135
16th to endDay
10%11%25%32%13%5%
144
January1st to 15thNight
5%319%44%23%4
780
16th to endNight
5%5%20%42%23%3
832
February1st to 15thNight
27%20%38%27%3
764
16th to endNight
39%29%43%13%
684
March1st to 15thNight
37%27%39%18%2
780
16th to endNight
26%22%42%22%2
832
April1st to 15thNight
38%29%41%15%1
663
16th to endNight
18%31%38%17%2
579
May1st to 15thNight
17%29%40%20%1
585
16th to endNight
2324%45%22%
611
June1st to 15thNight
4113%50%27%2
585
16th to endNight
39%44%41%1
585
July1st to 15thNight
46%35%46%6%
555
16th to endNight
3327%55%9%
612
August1st to 15thNight
4318%58%14%
575
16th to endNight
6%419%56%11%
621
September1st to 15thNight
7%16%26%52%6%
650
16th to endNight
6%111%34%40%6%
776
October1st to 15thNight
2116%40%33%5%
752
16th to endNight
2110%38%38%7%
768
November1st to 15thNight
2218%38%32%6%
760
16th to endNight
5%320%36%28%6%
780
December1st to 15thNight
5%420%39%25%4
780
16th to endNight
47%21%39%21%5%
832
Page generated at 2018-10-09 08:39:12. Version ac04

Copyright 2018 A. Danko


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