Carefree
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Carefree clear sky chart from 2005-11-05 to 2017-10-06.

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
77%
15718
37%
47123
33%
15680
81%
15680
55%
22281

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
69%
718
33%
2327
33%
716
75%
716
45%
1140
January16th to endNight
64%
768
36%
2496
35%
768
72%
768
42%
1279
February1st to 15thNight
73%
698
36%
2183
35%
698
80%
698
53%
1032
February16th to endNight
69%
632
35%
1889
37%
632
73%
632
46%
986
March1st to 15thNight
70%
720
40%
1980
34%
720
76%
720
59%
965
March16th to endNight
77%
768
40%
2112
32%
768
83%
768
62%
1001
April1st to 15thNight
72%
708
33%
1967
24%
708
77%
708
56%
966
April16th to endNight
72%
540
45%
1686
37%
540
81%
540
71%
656
May1st to 15thNight
78%
539
39%
1619
32%
539
83%
539
66%
683
May16th to endNight
81%
561
40%
1684
33%
561
85%
561
73%
673
June1st to 15thNight
86%
540
35%
1620
31%
540
87%
540
73%
652
June16th to endNight
90%
540
35%
1620
32%
540
90%
540
76%
638
July1st to 15thNight
86%
510
25%
1530
22%
510
86%
510
51%
760
July16th to endNight
83%
564
27%
1593
23%
531
84%
531
40%
886
August1st to 15thNight
86%
539
29%
1611
25%
536
86%
536
47%
829
August16th to endNight
85%
641
33%
1861
31%
641
85%
641
44%
1015
September1st to 15thNight
83%
720
33%
1980
29%
720
84%
720
52%
1035
September16th to endNight
85%
716
44%
1980
36%
716
88%
716
68%
893
October1st to 15thNight
80%
684
41%
1955
35%
684
83%
684
65%
883
October16th to endNight
82%
704
44%
2112
39%
704
87%
704
66%
908
November1st to 15thNight
83%
700
42%
2142
39%
700
87%
700
66%
907
November16th to endNight
76%
720
40%
2340
42%
720
80%
720
54%
1045
December1st to 15thNight
73%
720
36%
2340
36%
720
77%
720
47%
1126
December16th to endNight
67%
768
34%
2496
35%
768
71%
768
39%
1323

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
4212212346%68%
48067
Night
4212213335%67%
47320
TransparencyDay
17%2412%24%38%
47762
Night
18%2411%23%40%
47126
SeeingDay
4419%36%26%7%
5532
Night
5%19%39%38%5%
15729

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
6%31231234465%
1611
16th to endDay
9%222212346%63%
1728
February1st to 15thDay
5%312212336%64%
1676
16th to endDay
9%413213337%58%
1585
March1st to 15thDay
6%312213246%65%
1980
16th to endDay
331221423470%
2112
April1st to 15thDay
32221245%6%68%
1979
16th to endDay
221111113478%
2271
May1st to 15thDay
111112235%78%
2331
16th to endDay
2111111215%80%
2429
June1st to 15thDay
111111112480%
2340
16th to endDay
11111213382%
2340
July1st to 15thDay
321332446%9%58%
2340
16th to endDay
5%323436%6%7%11%43%
2467
August1st to 15thDay
33133345%5%9%55%
2340
16th to endDay
3233245%7%8%59%
2337
September1st to 15thDay
4312323445%63%
1980
16th to endDay
22111122380%
1980
October1st to 15thDay
211211322377%
1799
16th to endDay
11111213478%
1760
November1st to 15thDay
1212212245%73%
1714
16th to endDay
6%2112223472%
1620
December1st to 15thDay
7%31342334460%
1620
16th to endDay
9%424223345%57%
1728
January1st to 15thNight
6%32332223464%
2327
16th to endNight
10%31331222462%
2496
February1st to 15thNight
5%312212345%66%
2173
16th to endNight
8%313323435%60%
1889
March1st to 15thNight
5%31222335%68%
1980
16th to endNight
4112112236%71%
2112
April1st to 15thNight
4212323335%66%
1967
16th to endNight
2111112382%
1686
May1st to 15thNight
112212335%75%
1619
16th to endNight
2111112482%
1684
June1st to 15thNight
11111222480%
1620
16th to endNight
1111112383%
1620
July1st to 15thNight
1212335%46%10%57%
1620
16th to endNight
42235%37%6%7%11%46%
1701
August1st to 15thNight
2214325%6%6%10%53%
1620
16th to endNight
1215%5%35%5%5%7%56%
1861
September1st to 15thNight
3213235%5%5%8%60%
1980
16th to endNight
21121322378%
1980
October1st to 15thNight
321121123475%
1955
16th to endNight
121221123476%
2112
November1st to 15thNight
32122345%73%
2142
16th to endNight
5%2231222471%
2340
December1st to 15thNight
7%212313236%63%
2340
16th to endNight
10%324323335%57%
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
21%2414%27%29%
1612
16th to endDay
22%2317%25%28%
1728
February1st to 15thDay
19%25%16%26%29%
1676
16th to endDay
25%2217%28%23%
1585
March1st to 15thDay
19%119%31%36%
1980
16th to endDay
18%1310%31%33%
2112
April1st to 15thDay
15%2111%32%36%
1979
16th to endDay
11%128%25%51%
2271
May1st to 15thDay
9%228%25%52%
2331
16th to endDay
10%117%23%56%
2432
June1st to 15thDay
8%11416%67%
2340
16th to endDay
8%11312%72%
2340
July1st to 15thDay
19%410%15%17%32%
2201
16th to endDay
28%7%13%22%18%9%
2312
August1st to 15thDay
21%5%8%18%18%28%
2325
16th to endDay
19%5%7%16%27%23%
2337
September1st to 15thDay
21%35%14%22%31%
1980
16th to endDay
9%126%29%51%
1980
October1st to 15thDay
13%139%27%44%
1799
16th to endDay
11%147%27%47%
1760
November1st to 15thDay
12%1311%31%38%
1714
16th to endDay
15%2211%25%42%
1620
December1st to 15thDay
25%35%15%25%24%
1620
16th to endDay
27%3420%27%16%
1728
January1st to 15thNight
23%2411%25%32%
2327
16th to endNight
26%2211%26%29%
2496
February1st to 15thNight
19%26%13%25%33%
2184
16th to endNight
25%2312%27%27%
1889
March1st to 15thNight
17%228%26%42%
1980
16th to endNight
14%2310%31%37%
2112
April1st to 15thNight
18%238%27%39%
1967
16th to endNight
9%127%23%56%
1686
May1st to 15thNight
11%127%27%49%
1620
16th to endNight
9%17%19%61%
1685
June1st to 15thNight
9%11414%68%
1620
16th to endNight
8%238%75%
1620
July1st to 15thNight
19%411%14%15%33%
1530
16th to endNight
26%6%11%20%20%14%
1593
August1st to 15thNight
21%6%9%18%16%28%
1611
16th to endNight
24%5%7%14%21%26%
1861
September1st to 15thNight
20%38%17%20%29%
1980
16th to endNight
12%125%22%56%
1980
October1st to 15thNight
13%129%24%47%
1955
16th to endNight
12%139%18%54%
2112
November1st to 15thNight
12%1211%29%42%
2142
16th to endNight
18%139%22%44%
2340
December1st to 15thNight
22%2413%27%29%
2340
16th to endNight
29%2416%27%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
27%216%35%15%2
90
16th to endDay
13%312%35%25%10%
96
February1st to 15thDay
6%417%42%27%1
191
16th to endDay
13%8%28%32%16%1
238
March1st to 15thDay
6%7%27%35%18%5%
270
16th to endDay
39%33%29%20%3
288
April1st to 15thDay
6%13%24%31%16%7%
269
16th to endDay
316%37%29%10%2
270
May1st to 15thDay
211%27%38%15%3
288
16th to endDay
1430%36%21%4
330
June1st to 15thDay
1326%40%23%5%
315
16th to endDay
1113%42%30%10%
315
July1st to 15thDay
112%36%39%8%
305
16th to endDay
5%5%30%37%21%
327
August1st to 15thDay
35%34%38%17%
315
16th to endDay
5%36%43%14%
332
September1st to 15thDay
6%110%41%31%7%
315
16th to endDay
4317%39%26%8%
315
October1st to 15thDay
4120%39%26%6%
201
16th to endDay
49%37%42%6%
96
November1st to 15thDay
3112%46%27%8%
90
16th to endDay
7%26%35%28%1
90
December1st to 15thDay
4111%33%41%8%
90
16th to endDay
15%320%38%18%3
96
January1st to 15thNight
8%112%46%26%4
720
16th to endNight
11%213%42%26%3
768
February1st to 15thNight
7%111%47%29%2
704
16th to endNight
9%13%49%23%3
632
March1st to 15thNight
6%215%40%31%3
720
16th to endNight
3310%43%33%5%
768
April1st to 15thNight
4412%47%28%2
708
16th to endNight
1319%42%28%4
540
May1st to 15thNight
2312%44%32%4
540
16th to endNight
2111%39%39%4
563
June1st to 15thNight
27%44%42%2
540
16th to endNight
1434%53%6%
540
July1st to 15thNight
2328%60%5%
510
16th to endNight
4315%63%13%
564
August1st to 15thNight
3117%64%12%
539
16th to endNight
2220%62%12%
641
September1st to 15thNight
4427%55%8%
720
16th to endNight
35%37%42%9%
716
October1st to 15thNight
419%41%39%4
684
16th to endNight
28%38%39%9%
704
November1st to 15thNight
318%44%36%5%
700
16th to endNight
5%19%42%35%5%
720
December1st to 15thNight
8%110%42%35%2
720
16th to endNight
11%29%46%26%4
768
Page generated at 2017-10-07 11:07:48. Version ac04

Copyright 2017 A. Danko


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