McCloud Nature Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the McCloud Nature Park clear sky chart from 2005-11-05 to 2017-12-20.

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
40%
16211
19%
47990
12%
16170
46%
16170
25%
31644

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
19%
899
15%
2506
6%
895
28%
895
17%
1868
January16th to endNight
20%
942
13%
2648
6%
942
26%
942
17%
1972
February1st to 15thNight
21%
702
12%
2112
4%
701
28%
701
17%
1511
February16th to endNight
23%
631
16%
1893
7%
631
31%
631
19%
1341
March1st to 15thNight
26%
720
15%
2160
9%
720
30%
720
18%
1511
March16th to endNight
28%
690
16%
2035
7%
690
37%
690
21%
1414
April1st to 15thNight
33%
539
18%
1797
11%
539
44%
539
22%
1163
April16th to endNight
37%
540
21%
1715
12%
540
47%
540
25%
1081
May1st to 15thNight
36%
540
15%
1620
9%
540
43%
540
20%
1155
May16th to endNight
52%
561
18%
1614
12%
561
56%
561
28%
1052
June1st to 15thNight
60%
540
19%
1440
14%
540
62%
540
38%
857
June16th to endNight
62%
540
19%
1440
15%
540
65%
540
36%
892
July1st to 15thNight
69%
510
18%
1360
15%
510
71%
510
38%
829
July16th to endNight
76%
564
26%
1439
20%
531
78%
531
49%
784
August1st to 15thNight
74%
539
22%
1638
22%
536
76%
536
38%
932
August16th to endNight
71%
573
24%
1910
24%
573
74%
573
36%
1042
September1st to 15thNight
63%
591
26%
1851
24%
591
67%
591
34%
1062
September16th to endNight
63%
717
29%
1980
23%
717
66%
717
37%
1181
October1st to 15thNight
52%
720
28%
1986
21%
720
59%
720
35%
1204
October16th to endNight
33%
768
21%
2469
15%
768
42%
768
25%
1533
November1st to 15thNight
37%
760
25%
2471
17%
760
49%
760
27%
1476
November16th to endNight
31%
780
21%
2535
13%
780
41%
780
20%
1681
December1st to 15thNight
25%
861
12%
2616
6%
861
31%
861
16%
1927
December16th to endNight
16%
984
12%
2755
3%
984
24%
984
14%
2176

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
14%7%36%5%3445%7%36%
48855
Night
14%7%36%5%2445%6%39%
48162
Cloud CoverDay
14%7%36%5%3445%7%36%
48864
Night
14%7%36%42445%7%39%
48167
TransparencyDay
45%412%22%13%2
48545
Night
44%411%22%14%2
47990
SeeingDay
15%6%23%25%20%8%
6151
Night
17%8%27%29%15%1
16216

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
19%12%5%9%7%35%445%24%
1432
16th to endDay
13%15%5%9%6%34346%25%
1575
February1st to 15thDay
13%12%5%9%6%4445%5%26%
1750
16th to endDay
14%12%5%8%7%33346%28%
1580
March1st to 15thDay
20%10%47%6%24446%28%
1790
16th to endDay
16%11%47%5%24447%30%
2196
April1st to 15thDay
18%8%3443435%7%36%
2151
16th to endDay
18%9%25%5%3445%6%35%
2244
May1st to 15thDay
21%8%36%5%2445%6%31%
2331
16th to endDay
12%6%35%6%35%5%6%7%37%
2498
June1st to 15thDay
11%324435%5%5%9%44%
2520
16th to endDay
9%425%5%245%7%10%41%
2520
July1st to 15thDay
10%5%25%5%35%46%10%39%
2520
16th to endDay
5%3245%46%6%8%10%42%
2631
August1st to 15thDay
8%4235%345%7%10%44%
2310
16th to endDay
8%425%5%345%6%9%42%
2292
September1st to 15thDay
11%6%24435%5%5%6%43%
2096
16th to endDay
13%42342445%6%48%
1980
October1st to 15thDay
15%5%24435%35%8%41%
1971
16th to endDay
16%7%25%6%24446%38%
1755
November1st to 15thDay
14%5%345%33336%46%
1717
16th to endDay
17%10%46%5%23346%35%
1755
December1st to 15thDay
20%11%48%7%3434427%
1673
16th to endDay
21%13%6%8%5%34345%22%
1568
January1st to 15thNight
18%11%38%7%25%345%29%
2506
16th to endNight
15%12%7%8%6%23445%29%
2648
February1st to 15thNight
16%11%5%9%434335%31%
2110
16th to endNight
14%11%5%6%6%35%45%5%32%
1893
March1st to 15thNight
17%9%46%5%2445%6%32%
2147
16th to endNight
16%8%36%5%3435%6%34%
2035
April1st to 15thNight
15%7%34435%446%39%
1797
16th to endNight
15%7%25%433447%40%
1715
May1st to 15thNight
18%7%35%5%345%5%7%33%
1620
16th to endNight
11%5%246%35%5%6%8%41%
1612
June1st to 15thNight
9%5%2442336%8%49%
1440
16th to endNight
7%324435%5%6%10%44%
1440
July1st to 15thNight
8%4133345%7%9%47%
1440
16th to endNight
422342445%9%55%
1537
August1st to 15thNight
5%3144245%7%9%50%
1649
16th to endNight
6%415%424448%53%
1910
September1st to 15thNight
9%42442445%8%49%
1851
16th to endNight
9%424423447%51%
1980
October1st to 15thNight
11%424424446%50%
1986
16th to endNight
17%7%24423346%43%
2469
November1st to 15thNight
12%6%25%423447%46%
2471
16th to endNight
18%9%35%42335%6%36%
2535
December1st to 15thNight
18%11%6%9%6%2343429%
2616
16th to endNight
23%12%5%8%6%2433424%
2755

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
19%11%410%6%34345%24%
1432
16th to endDay
13%15%5%10%6%44446%25%
1575
February1st to 15thDay
14%11%5%10%6%45%45%5%26%
1750
16th to endDay
15%11%6%8%7%34346%27%
1580
March1st to 15thDay
20%9%47%6%3435%6%28%
1800
16th to endDay
16%10%46%5%34448%30%
2195
April1st to 15thDay
18%9%3433435%7%36%
2151
16th to endDay
17%8%25%6%3435%6%35%
2244
May1st to 15thDay
20%8%36%5%2445%6%31%
2331
16th to endDay
11%6%25%6%36%6%6%7%37%
2498
June1st to 15thDay
10%4245%345%6%8%44%
2520
16th to endDay
8%435%435%5%6%10%41%
2520
July1st to 15thDay
10%5%345%35%47%9%39%
2520
16th to endDay
5%3245%46%6%8%10%42%
2631
August1st to 15thDay
8%424435%5%7%9%43%
2310
16th to endDay
8%415%5%45%5%6%9%42%
2292
September1st to 15thDay
12%6%25%5%35%45%6%43%
2096
16th to endDay
12%4234245%47%48%
1980
October1st to 15thDay
15%5%344245%47%42%
1971
16th to endDay
16%7%25%5%345%46%38%
1755
November1st to 15thDay
13%5%345%24335%46%
1717
16th to endDay
18%9%46%5%23346%35%
1755
December1st to 15thDay
20%11%48%5%3444427%
1673
16th to endDay
22%13%6%9%5%3435%5%22%
1568
January1st to 15thNight
18%11%37%6%35%445%29%
2506
16th to endNight
15%12%7%7%6%34345%29%
2648
February1st to 15thNight
16%11%5%8%5%34345%31%
2103
16th to endNight
14%11%47%6%3445%5%31%
1893
March1st to 15thNight
18%8%46%43445%6%33%
2160
16th to endNight
17%8%36%5%25%35%6%34%
2035
April1st to 15thNight
15%7%345%34446%39%
1797
16th to endNight
15%6%35%42335%7%41%
1715
May1st to 15thNight
18%7%35%5%35%5%47%33%
1619
16th to endNight
11%434435%5%6%9%40%
1612
June1st to 15thNight
9%5%3442235%8%50%
1440
16th to endNight
7%4245%25%6%7%10%44%
1440
July1st to 15thNight
8%4134246%5%9%48%
1440
16th to endNight
421432445%10%55%
1537
August1st to 15thNight
5%314435%5%7%9%50%
1649
16th to endNight
6%315%5%3445%8%53%
1910
September1st to 15thNight
9%5%2442445%8%49%
1851
16th to endNight
9%5%2442345%7%51%
1980
October1st to 15thNight
11%424424446%50%
1986
16th to endNight
17%7%24423346%43%
2469
November1st to 15thNight
12%6%25%423446%46%
2471
16th to endNight
18%9%35%324346%37%
2535
December1st to 15thNight
19%9%6%9%5%33345%29%
2616
16th to endNight
23%12%5%8%5%3433424%
2755

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
61%29%15%9%
1433
16th to endDay
58%313%17%6%
1575
February1st to 15thDay
57%411%17%8%
1752
16th to endDay
56%212%21%6%
1580
March1st to 15thDay
56%413%17%7%
1800
16th to endDay
53%314%21%5%1
2196
April1st to 15thDay
46%410%23%13%
2151
16th to endDay
48%313%19%10%4
2244
May1st to 15thDay
52%412%20%9%
2331
16th to endDay
42%7%12%20%15%2
2502
June1st to 15thDay
35%5%13%26%16%2
2520
16th to endDay
36%5%15%22%17%3
2520
July1st to 15thDay
40%6%11%23%16%2
2371
16th to endDay
32%8%17%27%12%2
2466
August1st to 15thDay
34%6%13%25%18%2
2297
16th to endDay
36%6%11%23%15%6%
2292
September1st to 15thDay
39%5%9%22%18%4
2096
16th to endDay
34%5%9%25%22%2
1980
October1st to 15thDay
40%49%25%17%2
1971
16th to endDay
46%311%24%13%
1755
November1st to 15thDay
40%310%22%18%5%
1717
16th to endDay
50%39%23%12%1
1755
December1st to 15thDay
59%310%18%8%
1673
16th to endDay
63%210%17%4
1568
January1st to 15thNight
56%38%21%9%
2506
16th to endNight
57%212%19%7%
2648
February1st to 15thNight
55%213%18%8%
2112
16th to endNight
53%312%20%9%
1893
March1st to 15thNight
51%311%21%10%2
2160
16th to endNight
48%414%23%7%1
2035
April1st to 15thNight
45%310%22%15%2
1797
16th to endNight
43%310%21%14%6%
1715
May1st to 15thNight
49%6%11%19%11%
1620
16th to endNight
38%7%12%19%16%4
1614
June1st to 15thNight
32%311%28%20%2
1440
16th to endNight
33%5%14%22%19%4
1440
July1st to 15thNight
31%6%15%23%19%4
1360
16th to endNight
23%416%34%18%2
1439
August1st to 15thNight
27%7%14%25%22%2
1638
16th to endNight
29%5%11%26%20%7%
1910
September1st to 15thNight
32%410%24%21%6%
1851
16th to endNight
32%48%24%25%4
1980
October1st to 15thNight
33%410%25%22%3
1986
16th to endNight
42%210%26%15%2
2469
November1st to 15thNight
38%38%24%19%5%
2471
16th to endNight
48%210%24%13%
2535
December1st to 15thNight
57%210%17%10%
2616
16th to endNight
62%49%16%7%
2755

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%12%31%15%6%1
90
16th to endDay
12%22%42%19%2
96
February1st to 15thDay
23%14%42%15%4
90
16th to endDay
20%8%38%23%8%
81
March1st to 15thDay
31%16%36%13%2
90
16th to endDay
23%10%31%22%10%1
285
April1st to 15thDay
19%13%27%26%10%2
270
16th to endDay
22%7%28%21%15%5%
270
May1st to 15thDay
22%10%25%23%12%4
288
16th to endDay
15%429%23%18%9%
398
June1st to 15thDay
12%419%34%21%7%
495
16th to endDay
13%429%27%19%6%
495
July1st to 15thDay
13%220%28%21%13%
475
16th to endDay
5%113%29%31%17%
491
August1st to 15thDay
10%17%22%35%23%
313
16th to endDay
11%12%24%35%14%
332
September1st to 15thDay
12%312%26%29%14%
315
16th to endDay
14%313%21%30%15%
314
October1st to 15thDay
15%5%23%26%23%5%
306
16th to endDay
22%9%32%27%6%
144
November1st to 15thDay
19%10%20%24%17%8%
135
16th to endDay
23%11%37%20%7%
135
December1st to 15thDay
15%20%36%21%5%1
135
16th to endDay
29%11%47%8%3
108
January1st to 15thNight
23%13%37%22%3
900
16th to endNight
20%13%35%26%3
942
February1st to 15thNight
22%11%36%26%2
704
16th to endNight
20%10%39%26%3
631
March1st to 15thNight
22%12%33%26%5%
720
16th to endNight
20%9%34%26%7%1
690
April1st to 15thNight
17%11%32%29%8%
539
16th to endNight
19%8%30%30%10%1
540
May1st to 15thNight
21%6%30%30%11%
540
16th to endNight
13%223%34%23%3
563
June1st to 15thNight
12%218%46%17%1
540
16th to endNight
9%118%44%24%1
540
July1st to 15thNight
8%214%42%30%2
510
16th to endNight
6%18%40%37%6%
564
August1st to 15thNight
7%19%39%36%5%
539
16th to endNight
7%10%32%42%6%
573
September1st to 15thNight
12%314%34%29%5%
591
16th to endNight
11%414%30%35%4
717
October1st to 15thNight
13%7%20%33%19%5%
720
16th to endNight
22%8%32%24%10%
768
November1st to 15thNight
17%8%32%26%13%1
760
16th to endNight
22%12%27%27%8%
780
December1st to 15thNight
25%10%33%22%7%1
861
16th to endNight
30%10%35%19%4
984
Page generated at 2017-12-21 06:04:48. Version ac04

Copyright 2017 A. Danko


McCloud Nature Park Clear Sky Chart |Charts Home