Big Falls Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Big Falls Campground clear sky chart from 2005-11-05 to 2017-09-21.

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
63%
16192
34%
47019
26%
16152
70%
16152
51%
23404

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
50%
716
29%
2327
22%
716
60%
716
39%
1207
January16th to endNight
46%
768
31%
2332
21%
768
59%
768
36%
1308
February1st to 15thNight
51%
699
32%
2108
26%
698
61%
698
40%
1144
February16th to endNight
43%
632
28%
1895
23%
632
52%
632
31%
1122
March1st to 15thNight
50%
720
29%
2159
22%
720
62%
720
39%
1168
March16th to endNight
52%
768
30%
2040
21%
768
60%
768
44%
1150
April1st to 15thNight
43%
719
30%
1799
14%
719
52%
719
45%
1022
April16th to endNight
51%
720
34%
1800
15%
720
60%
720
53%
952
May1st to 15thNight
60%
557
35%
1637
22%
557
67%
557
57%
744
May16th to endNight
57%
561
34%
1685
21%
561
67%
561
57%
760
June1st to 15thNight
71%
540
33%
1620
26%
540
75%
540
69%
670
June16th to endNight
78%
540
37%
1620
30%
540
82%
540
81%
614
July1st to 15thNight
87%
510
30%
1530
26%
510
88%
510
65%
659
July16th to endNight
83%
589
32%
1616
26%
554
83%
554
57%
780
August1st to 15thNight
89%
717
37%
1790
24%
713
89%
713
75%
838
August16th to endNight
89%
764
43%
1910
30%
764
89%
764
75%
890
September1st to 15thNight
86%
720
40%
1872
31%
720
88%
720
72%
863
September16th to endNight
81%
680
47%
1881
40%
680
88%
680
80%
769
October1st to 15thNight
64%
660
38%
1815
30%
660
72%
660
56%
902
October16th to endNight
69%
704
39%
2132
35%
704
77%
704
55%
981
November1st to 15thNight
66%
700
35%
2275
31%
700
75%
700
53%
1031
November16th to endNight
62%
720
35%
2340
34%
720
70%
720
44%
1148
December1st to 15thNight
49%
720
31%
2340
25%
720
60%
720
34%
1284
December16th to endNight
43%
768
32%
2496
25%
768
55%
768
31%
1398

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
3413323345%64%
47837
Night
3413313335%66%
47221
TransparencyDay
20%36%14%27%27%
47535
Night
19%36%14%27%28%
47024
SeeingDay
7%13%36%31%8%2
5886
Night
5%6%20%31%28%7%
16204

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
5%6%1431445%6%56%
1611
16th to endDay
8%8%23433345%51%
1890
February1st to 15thDay
46%34424445%55%
1751
16th to endDay
7%10%36%5%22335%48%
1579
March1st to 15thDay
46%23333448%55%
1800
16th to endDay
36%3342445%7%53%
2181
April1st to 15thDay
6%6%24313335%58%
2149
16th to endDay
3312222347%65%
2160
May1st to 15thDay
233413345%66%
2313
16th to endDay
3211212237%70%
2429
June1st to 15thDay
1212212236%74%
2340
16th to endDay
2111112284%
2340
July1st to 15thDay
3212323345%67%
2340
16th to endDay
331342436%7%59%
2438
August1st to 15thDay
11222334473%
2160
16th to endDay
21232333472%
2292
September1st to 15thDay
2112213345%70%
2088
16th to endDay
21121232379%
1871
October1st to 15thDay
441231333467%
1815
16th to endDay
221221333472%
1738
November1st to 15thDay
342321233467%
1584
16th to endDay
5%5%13423236%60%
1620
December1st to 15thDay
5%7%245%36%46%6%47%
1620
16th to endDay
8%7%35%423335%51%
1728
January1st to 15thNight
46%35%32345%6%55%
2327
16th to endNight
7%7%25%413345%53%
2332
February1st to 15thNight
48%34323436%55%
2101
16th to endNight
5%9%36%43335%5%48%
1895
March1st to 15thNight
36%24435%346%55%
2159
16th to endNight
26%3333435%7%55%
2040
April1st to 15thNight
37%23313336%60%
1799
16th to endNight
2311214336%68%
1800
May1st to 15thNight
22213346%70%
1637
16th to endNight
1212222235%74%
1684
June1st to 15thNight
11211135%79%
1620
16th to endNight
1111288%
1620
July1st to 15thNight
21221322376%
1620
16th to endNight
2213322346%66%
1726
August1st to 15thNight
11221222379%
1800
16th to endNight
2111112381%
1910
September1st to 15thNight
11111223478%
1872
16th to endNight
11111386%
1881
October1st to 15thNight
3212312335%70%
1815
16th to endNight
211321323373%
2132
November1st to 15thNight
241331333468%
2275
16th to endNight
35%13423346%62%
2340
December1st to 15thNight
7%6%245%24347%51%
2340
16th to endNight
7%7%25%413445%52%
2496

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
25%47%15%27%21%
1612
16th to endDay
31%36%14%21%21%
1890
February1st to 15thDay
26%5%5%15%24%22%
1751
16th to endDay
37%26%15%26%11%
1579
March1st to 15thDay
24%37%18%25%19%
1800
16th to endDay
27%49%19%25%13%
2181
April1st to 15thDay
27%37%21%29%10%
2149
16th to endDay
17%39%19%32%16%
2160
May1st to 15thDay
18%37%19%31%20%
2313
16th to endDay
15%48%21%35%15%
2432
June1st to 15thDay
12%25%13%30%35%
2340
16th to endDay
8%22419%62%
2340
July1st to 15thDay
14%35%10%20%44%
2201
16th to endDay
19%5%7%17%22%25%
2285
August1st to 15thDay
11%35%10%24%43%
2146
16th to endDay
12%3410%34%33%
2292
September1st to 15thDay
12%5%6%8%30%36%
2088
16th to endDay
10%1211%30%43%
1871
October1st to 15thDay
19%2415%28%29%
1815
16th to endDay
15%36%10%26%36%
1738
November1st to 15thDay
20%26%14%30%25%
1584
16th to endDay
24%35%12%26%27%
1620
December1st to 15thDay
30%49%15%19%20%
1620
16th to endDay
33%36%18%20%17%
1728
January1st to 15thNight
26%46%14%23%25%
2327
16th to endNight
31%28%12%19%25%
2332
February1st to 15thNight
27%46%13%24%24%
2112
16th to endNight
35%37%13%23%16%
1895
March1st to 15thNight
27%37%16%23%21%
2159
16th to endNight
24%48%20%27%14%
2040
April1st to 15thNight
24%39%21%26%14%
1799
16th to endNight
17%47%19%34%17%
1800
May1st to 15thNight
13%37%21%34%18%
1638
16th to endNight
13%47%22%35%16%
1685
June1st to 15thNight
9%25%13%29%39%
1620
16th to endNight
5%36%23%60%
1620
July1st to 15thNight
10%35%9%20%50%
1530
16th to endNight
16%48%19%25%26%
1616
August1st to 15thNight
8%2314%27%42%
1790
16th to endNight
8%2310%35%38%
1910
September1st to 15thNight
9%2411%31%39%
1872
16th to endNight
6%1213%33%43%
1881
October1st to 15thNight
18%2415%31%28%
1815
16th to endNight
16%35%8%27%39%
2132
November1st to 15thNight
18%2412%31%30%
2275
16th to endNight
22%35%13%24%30%
2340
December1st to 15thNight
30%46%14%21%22%
2340
16th to endNight
31%48%13%23%19%
2496

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
33%10%28%24%21
90
16th to endDay
18%17%29%26%5%1
258
February1st to 15thDay
9%20%29%29%9%1
266
16th to endDay
19%23%31%20%5%
238
March1st to 15thDay
12%17%38%20%8%1
270
16th to endDay
9%23%37%21%7%
288
April1st to 15thDay
13%26%37%14%7%1
269
16th to endDay
6%30%40%18%21
270
May1st to 15thDay
7%20%39%23%6%2
288
16th to endDay
417%45%26%5%1
330
June1st to 15thDay
212%47%27%6%3
315
16th to endDay
5%436%38%11%4
315
July1st to 15thDay
3131%45%12%5%
305
16th to endDay
3122%53%10%7%
327
August1st to 15thDay
2437%41%7%6%
315
16th to endDay
2130%48%10%6%
332
September1st to 15thDay
35%44%34%11%
315
16th to endDay
37%39%39%7%2
276
October1st to 15thDay
6%15%42%28%6%
255
16th to endDay
8%11%31%32%15%
198
November1st to 15thDay
311%22%28%31%3
90
16th to endDay
11%15%32%28%12%
90
December1st to 15thDay
5%13%34%31%12%3
90
16th to endDay
18%14%31%23%10%1
96
January1st to 15thNight
9%6%25%32%18%7%
720
16th to endNight
12%6%26%28%20%4
768
February1st to 15thNight
9%7%25%31%19%5%
704
16th to endNight
13%10%28%25%17%4
632
March1st to 15thNight
6%10%25%33%19%5%
720
16th to endNight
5%11%26%32%19%5%
768
April1st to 15thNight
7%14%29%28%16%4
719
16th to endNight
411%29%27%20%7%
720
May1st to 15thNight
27%24%40%19%4
558
16th to endNight
27%29%31%26%3
563
June1st to 15thNight
1321%45%25%2
540
16th to endNight
118%49%27%2
540
July1st to 15thNight
25%39%45%8%
510
16th to endNight
26%32%50%8%
589
August1st to 15thNight
1431%51%12%
717
16th to endNight
3424%52%16%
764
September1st to 15thNight
16%28%48%13%
720
16th to endNight
1112%28%42%13%
680
October1st to 15thNight
4421%32%29%7%
660
16th to endNight
25%17%28%31%13%
704
November1st to 15thNight
4321%33%28%9%
700
16th to endNight
5%6%19%34%23%10%
720
December1st to 15thNight
10%6%26%29%21%5%
720
16th to endNight
13%11%25%26%17%5%
768
Page generated at 2017-09-22 04:35:29. Version ac04

Copyright 2017 A. Danko


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