ScrubGrass Campgrounds
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the ScrubGrass Campgrounds clear sky chart from 2005-11-05 to 2017-09-22.

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
46%
15593
26%
46999
18%
15549
54%
15549
29%
27608

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
29%
899
27%
2327
11%
895
40%
895
26%
1499
January16th to endNight
28%
960
26%
2496
10%
960
39%
960
26%
1635
February1st to 15thNight
25%
776
21%
2184
8%
773
34%
773
24%
1407
February16th to endNight
27%
631
26%
1893
10%
631
39%
631
24%
1161
March1st to 15thNight
30%
588
21%
2028
13%
588
39%
588
20%
1262
March16th to endNight
37%
576
23%
2067
17%
576
47%
576
24%
1200
April1st to 15thNight
37%
539
26%
1797
19%
539
50%
539
28%
1004
April16th to endNight
38%
540
26%
1800
17%
540
54%
540
27%
1007
May1st to 15thNight
45%
540
20%
1800
17%
540
53%
540
25%
1064
May16th to endNight
52%
562
23%
1659
17%
561
59%
561
30%
959
June1st to 15thNight
64%
540
25%
1440
19%
540
69%
540
40%
801
June16th to endNight
69%
540
28%
1440
21%
540
74%
540
41%
806
July1st to 15thNight
71%
510
18%
1509
19%
510
73%
510
33%
883
July16th to endNight
70%
564
24%
1594
23%
531
79%
531
38%
867
August1st to 15thNight
73%
539
22%
1745
26%
536
75%
536
34%
937
August16th to endNight
68%
573
25%
1910
28%
573
71%
573
30%
1078
September1st to 15thNight
64%
540
25%
1800
27%
540
66%
540
29%
1046
September16th to endNight
66%
613
33%
1836
26%
613
71%
613
36%
1017
October1st to 15thNight
61%
660
33%
1980
27%
660
65%
660
40%
1032
October16th to endNight
55%
704
37%
2112
26%
704
65%
704
40%
1117
November1st to 15thNight
45%
700
30%
2154
22%
700
54%
700
33%
1180
November16th to endNight
36%
720
29%
2340
17%
720
50%
720
25%
1360
December1st to 15thNight
34%
819
22%
2439
11%
819
44%
819
21%
1546
December16th to endNight
28%
960
22%
2649
9%
960
38%
960
23%
1740

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
12%5%245%3445%7%44%
47863
Night
12%424323447%50%
47197
TransparencyDay
38%5%11%21%18%4
47564
Night
33%410%22%22%6%
47001
SeeingDay
11%10%14%22%25%14%
5660
Night
12%18%18%27%20%3
15595

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
20%6%2432333446%
1611
16th to endDay
17%6%3431233446%
1728
February1st to 15thDay
17%6%2442333447%
1675
16th to endDay
17%8%35%323235%43%
1580
March1st to 15thDay
18%7%26%5%34335%38%
1941
16th to endDay
12%6%36%5%34346%42%
2155
April1st to 15thDay
12%425%5%2445%6%46%
2151
16th to endDay
11%5%35%5%2445%5%46%
2160
May1st to 15thDay
15%6%35%5%35%45%5%39%
2151
16th to endDay
9%425%7%46%6%6%8%38%
2449
June1st to 15thDay
5%325%6%46%5%5%8%45%
2520
16th to endDay
5%3245%36%5%6%10%45%
2520
July1st to 15thDay
8%425%5%46%6%8%11%35%
2356
16th to endDay
7%3245%37%6%7%9%40%
2466
August1st to 15thDay
6%315%6%35%7%7%9%41%
2205
16th to endDay
10%4245%35%6%6%8%41%
2292
September1st to 15thDay
9%415%5%45%5%5%7%43%
2160
16th to endDay
11%413423447%51%
1922
October1st to 15thDay
10%31442245%7%53%
1650
16th to endDay
16%31311123460%
1760
November1st to 15thDay
12%323322235%58%
1701
16th to endDay
16%6%25%323325%48%
1620
December1st to 15thDay
20%8%24422435%40%
1518
16th to endDay
18%5%345%24345%40%
1572
January1st to 15thNight
16%6%24312235%48%
2327
16th to endNight
18%6%2431344446%
2496
February1st to 15thNight
18%6%2433323447%
2175
16th to endNight
16%5%24423335%48%
1893
March1st to 15thNight
16%425%5%34445%43%
2028
16th to endNight
15%5%24322345%48%
2067
April1st to 15thNight
11%224424447%50%
1797
16th to endNight
10%43442335%6%52%
1800
May1st to 15thNight
13%423323447%48%
1799
16th to endNight
8%324325%5%5%9%49%
1659
June1st to 15thNight
322242346%11%55%
1440
16th to endNight
3123325%46%9%56%
1440
July1st to 15thNight
5%3235%36%6%8%9%46%
1599
16th to endNight
32233246%8%12%51%
1702
August1st to 15thNight
34124345%7%10%52%
1755
16th to endNight
7%4144245%6%11%46%
1910
September1st to 15thNight
10%5%24434446%50%
1800
16th to endNight
8%42322345%6%55%
1836
October1st to 15thNight
8%313222346%60%
1980
16th to endNight
13%31211123461%
2112
November1st to 15thNight
10%423324345%56%
2154
16th to endNight
15%5%2332333452%
2340
December1st to 15thNight
17%6%24313345%45%
2439
16th to endNight
18%8%24313245%45%
2649

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
42%26%23%19%5%
1612
16th to endDay
42%26%22%21%4
1728
February1st to 15thDay
42%26%25%17%4
1677
16th to endDay
45%26%22%18%5%
1580
March1st to 15thDay
49%37%19%14%5%
1941
16th to endDay
41%5%12%23%15%1
2157
April1st to 15thDay
37%5%10%21%19%4
2151
16th to endDay
38%48%22%23%2
2160
May1st to 15thDay
44%410%16%18%4
2151
16th to endDay
41%8%15%22%11%1
2453
June1st to 15thDay
34%7%12%24%19%1
2520
16th to endDay
31%7%13%24%19%4
2520
July1st to 15thDay
36%9%17%22%10%3
2217
16th to endDay
33%8%17%24%13%2
2311
August1st to 15thDay
33%8%17%23%13%2
2191
16th to endDay
37%7%15%22%13%3
2292
September1st to 15thDay
38%8%12%17%16%6%
2160
16th to endDay
31%410%20%22%10%
1922
October1st to 15thDay
30%39%19%25%11%
1650
16th to endDay
30%2420%31%12%
1760
November1st to 15thDay
30%27%20%29%8%
1701
16th to endDay
40%27%20%24%5%
1620
December1st to 15thDay
46%29%19%14%6%
1518
16th to endDay
46%210%18%18%4
1572
January1st to 15thNight
39%25%21%23%6%
2327
16th to endNight
40%36%19%22%7%
2496
February1st to 15thNight
42%27%20%21%4
2184
16th to endNight
39%36%22%20%7%
1893
March1st to 15thNight
42%49%18%16%8%
2028
16th to endNight
37%310%22%22%3
2067
April1st to 15thNight
32%39%23%22%7%
1797
16th to endNight
33%39%23%24%5%
1800
May1st to 15thNight
35%5%10%21%21%5%
1800
16th to endNight
30%6%18%24%18%2
1661
June1st to 15thNight
22%6%14%32%22%1
1440
16th to endNight
22%6%13%28%25%3
1440
July1st to 15thNight
27%9%18%27%12%4
1509
16th to endNight
21%9%18%30%18%2
1594
August1st to 15thNight
24%8%19%25%17%3
1745
16th to endNight
30%6%16%24%17%3
1910
September1st to 15thNight
33%5%11%23%18%7%
1800
16th to endNight
27%5%7%21%26%11%
1836
October1st to 15thNight
24%39%21%26%14%
1980
16th to endNight
27%25%19%32%14%
2112
November1st to 15thNight
30%38%20%25%11%
2154
16th to endNight
36%25%16%29%8%
2340
December1st to 15thNight
40%49%20%17%7%
2439
16th to endNight
42%38%21%19%4
2649

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
17%11%37%18%13%1
90
16th to endDay
21%9%51%11%6%
96
February1st to 15thDay
13%13%40%25%43
90
16th to endDay
17%14%38%23%41
81
March1st to 15thDay
30%10%37%17%31
90
16th to endDay
7%19%19%35%17%
141
April1st to 15thDay
14%17%29%22%11%3
270
16th to endDay
15%16%20%27%18%2
270
May1st to 15thDay
16%15%20%27%17%3
288
16th to endDay
12%14%17%24%21%9%
448
June1st to 15thDay
7%12%8%25%30%16%
495
16th to endDay
413%8%26%31%15%
495
July1st to 15thDay
8%8%5%24%34%18%
475
16th to endDay
5%13%212%34%32%
515
August1st to 15thDay
9%6%312%38%28%
358
16th to endDay
18%5%415%30%26%
332
September1st to 15thDay
9%5%8%16%31%27%
315
16th to endDay
10%5%8%18%35%22%
259
October1st to 15thDay
5%122%32%25%13%
90
16th to endDay
17%113%31%29%7%
96
November1st to 15thDay
17%225%32%18%3
90
16th to endDay
22%7%28%26%12%2
90
December1st to 15thDay
28%5%23%24%13%4
90
16th to endDay
15%16%35%23%7%1
96
January1st to 15thNight
17%23%26%26%6%
900
16th to endNight
16%22%29%28%2
960
February1st to 15thNight
17%25%29%23%4
776
16th to endNight
14%23%31%26%3
631
March1st to 15thNight
17%22%25%30%4
588
16th to endNight
17%20%22%27%12%
576
April1st to 15thNight
10%21%28%29%8%1
539
16th to endNight
10%21%24%29%12%1
540
May1st to 15thNight
14%19%17%36%11%1
540
16th to endNight
7%18%15%30%24%3
563
June1st to 15thNight
417%6%32%33%5%
540
16th to endNight
216%5%25%41%7%
540
July1st to 15thNight
311%327%45%8%
510
16th to endNight
416%117%48%10%
564
August1st to 15thNight
5%9%221%48%11%
539
16th to endNight
10%8%323%44%9%
573
September1st to 15thNight
10%9%8%24%37%9%
540
16th to endNight
9%9%6%27%38%7%
613
October1st to 15thNight
8%11%14%32%27%5%
660
16th to endNight
12%12%16%32%24%1
704
November1st to 15thNight
10%18%22%26%20%2
700
16th to endNight
15%21%23%25%13%1
720
December1st to 15thNight
19%22%20%27%9%
819
16th to endNight
18%23%25%26%5%
960
Page generated at 2017-09-23 05:43:40. Version ac04

Copyright 2017 A. Danko


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