Cartwright
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cartwright clear sky chart from 2005-11-05 to 2019-06-02.

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
21%
16910
10%
53706
4%
16865
28%
16865
11%
40978

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
15%
899
12%
3344
4%
896
26%
896
9%
2471
January16th to endNight
21%
960
18%
3202
6%
960
35%
960
14%
2244
February1st to 15thNight
22%
884
15%
2881
5%
881
34%
881
15%
2019
February16th to endNight
19%
746
10%
2311
2%
746
26%
746
12%
1771
March1st to 15thNight
22%
840
11%
2515
5%
838
28%
838
12%
1969
March16th to endNight
18%
702
9%
2351
5%
702
25%
702
8%
1874
April1st to 15thNight
21%
629
12%
2040
8%
629
28%
629
11%
1570
April16th to endNight
18%
623
11%
1763
4%
623
24%
623
11%
1358
May1st to 15thNight
21%
630
6%
1600
2%
630
24%
630
11%
1310
May16th to endNight
23%
642
1%
1518
0%
642
24%
642
10%
1288
June1st to 15thNight
19%
392
0%
1177
0%
392
19%
392
7%
1004
June16th to endNight
32%
390
0%
1170
0%
390
32%
390
12%
901
July1st to 15thNight
30%
370
0%
1110
0%
370
30%
370
10%
908
July16th to endNight
33%
552
1%
1341
0%
519
35%
519
12%
1088
August1st to 15thNight
36%
574
4%
1522
2%
570
37%
570
17%
1172
August16th to endNight
37%
621
9%
1796
4%
621
40%
621
15%
1348
September1st to 15thNight
26%
585
10%
1957
7%
585
33%
585
14%
1418
September16th to endNight
19%
583
9%
2145
5%
583
26%
583
10%
1578
October1st to 15thNight
20%
752
11%
2366
3%
752
28%
752
11%
1826
October16th to endNight
19%
896
9%
2704
4%
896
23%
896
9%
2235
November1st to 15thNight
15%
880
10%
2942
2%
880
22%
880
8%
2310
November16th to endNight
14%
900
13%
3150
3%
900
26%
900
9%
2334
December1st to 15thNight
15%
900
11%
3217
3%
900
25%
900
10%
2319
December16th to endNight
16%
960
13%
3584
6%
960
27%
960
9%
2663

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
20%12%47%5%34446%26%
54652
Night
19%13%5%7%5%34445%27%
53854
TransparencyDay
60%6%10%15%6%
54312
Night
59%5%10%16%7%
53712
SeeingDay
29%15%23%19%9%2
9940
Night
25%20%25%20%7%1
16912

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
14%14%5%7%425%445%28%
1254
16th to endDay
11%11%6%7%5%3445%6%32%
1721
February1st to 15thDay
11%12%5%7%5%3445%5%32%
1640
16th to endDay
15%16%46%5%33446%29%
1733
March1st to 15thDay
14%18%5%7%6%4433427%
2090
16th to endDay
17%15%5%8%6%35%33425%
2576
April1st to 15thDay
17%14%6%8%6%24346%25%
2569
16th to endDay
18%13%5%7%6%33446%26%
2801
May1st to 15thDay
22%13%47%6%25%45%7%20%
3010
16th to endDay
27%13%46%5%2444421%
3309
June1st to 15thDay
30%14%47%42434418%
3136
16th to endDay
23%9%35%42446%6%28%
3120
July1st to 15thDay
24%9%35%5%25%5%5%7%23%
3120
16th to endDay
23%9%46%5%35%5%5%7%24%
3076
August1st to 15thDay
21%9%36%5%35%45%6%27%
2680
16th to endDay
21%8%36%43445%6%31%
2757
September1st to 15thDay
20%9%26%5%3445%7%30%
2333
16th to endDay
21%10%36%6%3445%5%28%
2145
October1st to 15thDay
23%14%37%5%2344425%
1922
16th to endDay
29%14%47%43423421%
1872
November1st to 15thDay
20%14%46%5%33345%28%
1574
16th to endDay
20%15%35%433447%27%
1470
December1st to 15thDay
10%15%48%6%345%47%30%
1400
16th to endDay
15%14%5%8%424345%30%
1344
January1st to 15thNight
15%15%6%7%5%24445%28%
3344
16th to endNight
12%12%5%7%5%345%45%33%
3202
February1st to 15thNight
11%13%5%8%6%34445%34%
2880
16th to endNight
16%15%5%8%5%3443427%
2311
March1st to 15thNight
12%18%7%8%6%34335%24%
2507
16th to endNight
19%18%6%7%5%3435%322%
2351
April1st to 15thNight
19%15%5%7%6%3333426%
2040
16th to endNight
21%13%47%5%24345%27%
1763
May1st to 15thNight
23%15%47%43335%5%22%
1600
16th to endNight
30%13%46%5%2333420%
1517
June1st to 15thNight
28%16%5%7%42433317%
1177
16th to endNight
25%11%35%4335%5%5%27%
1170
July1st to 15thNight
25%10%48%5%345%5%5%21%
1170
16th to endNight
22%9%37%6%46%5%45%23%
1428
August1st to 15thNight
22%9%35%5%3445%6%30%
1533
16th to endNight
17%8%26%5%346%6%7%30%
1796
September1st to 15thNight
21%9%26%5%35%35%6%31%
1957
16th to endNight
22%10%36%5%34446%27%
2145
October1st to 15thNight
21%13%46%5%33445%27%
2366
16th to endNight
30%16%35%5%3333420%
2704
November1st to 15thNight
20%16%46%6%3434326%
2942
16th to endNight
19%12%46%5%34346%29%
3150
December1st to 15thNight
11%12%5%6%6%35%5%6%6%30%
3217
16th to endNight
17%12%6%7%5%2443428%
3584

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
57%5%10%15%10%
1255
16th to endDay
53%48%19%12%
1721
February1st to 15thDay
53%49%17%13%1
1643
16th to endDay
58%47%15%12%
1733
March1st to 15thDay
61%49%16%8%
2100
16th to endDay
64%27%12%10%1
2576
April1st to 15thDay
62%5%9%12%8%1
2569
16th to endDay
61%5%9%15%7%
2801
May1st to 15thDay
65%5%11%13%4
3010
16th to endDay
67%5%9%13%4
3313
June1st to 15thDay
70%5%9%10%4
3136
16th to endDay
56%8%10%18%5%
3120
July1st to 15thDay
59%9%12%14%4
2951
16th to endDay
58%8%12%14%5%
2901
August1st to 15thDay
57%8%14%17%2
2666
16th to endDay
53%7%14%17%5%
2757
September1st to 15thDay
55%6%12%19%5%
2333
16th to endDay
57%6%11%16%6%1
2145
October1st to 15thDay
62%5%10%14%6%
1922
16th to endDay
69%48%13%4
1872
November1st to 15thDay
58%6%11%16%5%1
1574
16th to endDay
58%5%10%19%5%
1470
December1st to 15thDay
55%7%13%16%7%
1400
16th to endDay
57%410%17%10%
1344
January1st to 15thNight
58%5%8%15%9%1
3344
16th to endNight
52%49%17%14%2
3202
February1st to 15thNight
52%411%20%10%1
2881
16th to endNight
60%48%15%10%
2311
March1st to 15thNight
63%38%15%7%
2520
16th to endNight
67%37%13%7%
2351
April1st to 15thNight
62%38%14%9%1
2040
16th to endNight
59%5%8%15%11%
1763
May1st to 15thNight
64%5%9%13%6%
1600
16th to endNight
68%5%7%12%4
1519
June1st to 15thNight
71%5%8%10%3
1177
16th to endNight
57%7%11%17%5%
1170
July1st to 15thNight
62%9%10%14%2
1110
16th to endNight
60%9%14%13%2
1341
August1st to 15thNight
53%9%18%16%2
1522
16th to endNight
51%11%13%19%4
1796
September1st to 15thNight
53%7%14%19%5%
1957
16th to endNight
58%5%13%14%7%
2145
October1st to 15thNight
60%5%10%15%8%
2366
16th to endNight
69%38%13%4
2704
November1st to 15thNight
64%410%14%5%
2942
16th to endNight
58%5%10%18%6%
3150
December1st to 15thNight
53%7%13%18%6%
3217
16th to endNight
59%5%8%17%9%
3584

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
18%10%35%18%15%2
120
16th to endDay
17%20%30%24%5%1
330
February1st to 15thDay
15%18%33%22%7%2
326
16th to endDay
22%20%26%23%5%1
290
March1st to 15thDay
21%20%27%19%8%2
330
16th to endDay
24%19%29%20%5%1
393
April1st to 15thDay
22%20%29%18%6%2
446
16th to endDay
26%21%25%16%7%2
587
May1st to 15thDay
32%14%21%17%10%2
618
16th to endDay
38%13%18%16%8%3
679
June1st to 15thDay
42%15%11%16%9%4
575
16th to endDay
29%14%16%22%12%4
570
July1st to 15thDay
30%11%22%22%10%3
550
16th to endDay
31%12%15%23%14%3
594
August1st to 15thDay
30%8%17%24%16%3
550
16th to endDay
25%9%21%25%13%3
602
September1st to 15thDay
31%11%29%22%4
372
16th to endDay
30%14%32%17%4
314
October1st to 15thDay
32%18%25%16%5%1
315
16th to endDay
41%12%22%13%9%1
336
November1st to 15thDay
31%21%27%13%5%
325
16th to endDay
30%19%24%21%4
330
December1st to 15thDay
18%20%37%15%8%
260
16th to endDay
23%15%36%19%31
128
January1st to 15thNight
23%22%30%17%5%
900
16th to endNight
15%25%30%21%6%
960
February1st to 15thNight
17%21%31%23%41
884
16th to endNight
22%22%28%18%7%2
746
March1st to 15thNight
19%24%24%21%8%2
840
16th to endNight
29%22%22%19%5%
702
April1st to 15thNight
24%24%22%17%9%2
629
16th to endNight
26%21%26%18%6%1
623
May1st to 15thNight
28%18%21%18%11%1
630
16th to endNight
35%18%14%17%11%2
643
June1st to 15thNight
37%17%17%13%9%3
392
16th to endNight
25%17%15%23%14%2
390
July1st to 15thNight
29%12%17%27%12%
370
16th to endNight
25%16%16%26%13%1
552
August1st to 15thNight
25%10%19%27%16%
574
16th to endNight
22%10%21%32%10%1
621
September1st to 15thNight
28%13%26%24%6%
585
16th to endNight
27%17%30%20%3
583
October1st to 15thNight
30%16%24%20%5%1
752
16th to endNight
40%13%20%18%6%1
896
November1st to 15thNight
28%20%29%15%4
880
16th to endNight
25%24%30%16%3
900
December1st to 15thNight
18%27%33%15%5%
900
16th to endNight
23%23%27%19%5%
960
Page generated at 2019-06-02 20:43:06. Version ac04

Copyright 2019 A. Danko


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