Lipantitlan State Historic Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lipantitlan State Historic Site clear sky chart from 2005-11-05 to 2019-06-10.

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
53%
17538
23%
53937
18%
17494
59%
17494
32%
31987

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
39%
1047
23%
2717
11%
1045
45%
1045
29%
1816
January16th to endNight
41%
990
23%
2782
11%
990
47%
990
29%
1780
February1st to 15thNight
36%
824
23%
2472
11%
820
45%
820
25%
1597
February16th to endNight
26%
719
22%
2189
8%
719
38%
719
27%
1353
March1st to 15thNight
34%
630
23%
2310
14%
630
47%
630
22%
1417
March16th to endNight
36%
672
22%
2464
14%
672
47%
672
26%
1426
April1st to 15thNight
35%
629
21%
2307
12%
629
47%
629
25%
1355
April16th to endNight
33%
624
21%
2145
14%
624
45%
624
24%
1328
May1st to 15thNight
40%
629
22%
1890
16%
629
47%
629
28%
1194
May16th to endNight
50%
659
23%
1972
17%
657
60%
657
33%
1174
June1st to 15thNight
75%
612
23%
1836
24%
612
79%
612
48%
941
June16th to endNight
71%
585
17%
1755
19%
585
73%
585
35%
1023
July1st to 15thNight
80%
555
18%
1665
21%
555
82%
555
39%
931
July16th to endNight
87%
612
23%
1738
26%
579
88%
579
50%
875
August1st to 15thNight
91%
575
28%
1821
33%
572
91%
572
57%
814
August16th to endNight
81%
621
18%
2180
21%
621
82%
621
35%
1163
September1st to 15thNight
75%
585
17%
2145
22%
585
76%
585
28%
1247
September16th to endNight
69%
582
22%
2145
25%
582
70%
582
26%
1272
October1st to 15thNight
79%
588
33%
2148
34%
588
80%
588
43%
1009
October16th to endNight
63%
832
33%
2496
25%
832
66%
832
43%
1331
November1st to 15thNight
57%
820
26%
2460
19%
820
60%
820
33%
1460
November16th to endNight
53%
978
29%
2658
17%
978
60%
978
37%
1592
December1st to 15thNight
44%
1050
26%
2730
15%
1050
49%
1050
28%
1851
December16th to endNight
36%
1120
20%
2912
11%
1120
40%
1120
25%
2038

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
11%5%25%5%35%5%5%7%41%
54565
Night
11%5%2432345%8%49%
54133
TransparencyDay
39%6%11%19%15%7%
54265
Night
33%6%14%22%15%8%
53938
SeeingDay
12%320%32%24%7%
7384
Night
14%322%37%20%1
17542

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
21%6%25%422335%39%
1881
16th to endDay
16%6%34323346%43%
2159
February1st to 15thDay
20%7%35%423345%39%
2050
16th to endDay
19%6%34423245%42%
1855
March1st to 15thDay
21%6%3442345%7%35%
2310
16th to endDay
12%6%35%5%24447%43%
2462
April1st to 15thDay
12%5%2433446%7%45%
2301
16th to endDay
14%7%245%24346%43%
2413
May1st to 15thDay
9%6%36%5%35%5%6%7%39%
2721
16th to endDay
6%425%5%46%6%6%9%42%
2846
June1st to 15thDay
3313446%5%7%11%48%
2653
16th to endDay
7%437%6%47%5%8%9%35%
2535
July1st to 15thDay
7%5%36%5%47%6%6%9%37%
2535
16th to endDay
5%3246%46%6%6%10%43%
2674
August1st to 15thDay
21135%346%7%11%51%
2378
16th to endDay
5%426%6%37%6%7%11%37%
2371
September1st to 15thDay
10%6%37%7%5%6%7%7%8%28%
2145
16th to endDay
9%5%36%7%46%5%6%9%35%
2145
October1st to 15thDay
7%3145%345%6%8%47%
2127
16th to endDay
10%214324435%56%
2080
November1st to 15thDay
11%6%36%6%34446%41%
2058
16th to endDay
13%5%25%5%2344447%
1960
December1st to 15thDay
21%7%35%423345%38%
1890
16th to endDay
19%7%26%424346%36%
2016
January1st to 15thNight
21%6%24322335%45%
2717
16th to endNight
17%5%23423345%45%
2782
February1st to 15thNight
18%6%24423445%42%
2462
16th to endNight
16%7%24313346%45%
2189
March1st to 15thNight
17%6%25%323348%41%
2310
16th to endNight
13%6%24423347%48%
2464
April1st to 15thNight
12%426%425%448%43%
2307
16th to endNight
15%6%2443345%7%41%
2145
May1st to 15thNight
10%5%245%35%5%6%10%39%
1889
16th to endNight
6%4135%45%5%7%11%44%
1971
June1st to 15thNight
3222245%7%10%57%
1836
16th to endNight
5%323325%5%7%12%48%
1755
July1st to 15thNight
432332437%12%52%
1755
16th to endNight
21123135%6%12%57%
1846
August1st to 15thNight
112133410%68%
1831
16th to endNight
341332446%9%55%
2180
September1st to 15thNight
7%425%4335%7%9%46%
2145
16th to endNight
9%6%35%42445%9%44%
2145
October1st to 15thNight
5%21231335%6%64%
2148
16th to endNight
9%31331223463%
2496
November1st to 15thNight
10%425%423446%51%
2460
16th to endNight
12%5%13323345%55%
2658
December1st to 15thNight
21%5%34322345%42%
2730
16th to endNight
20%8%25%423336%39%
2912

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
47%36%12%15%12%
1882
16th to endDay
41%38%16%17%11%
2159
February1st to 15thDay
47%37%11%15%13%
2051
16th to endDay
44%47%16%17%9%
1855
March1st to 15thDay
47%5%9%13%15%8%
2310
16th to endDay
39%5%11%16%15%10%
2464
April1st to 15thDay
36%5%10%17%18%11%
2301
16th to endDay
40%5%8%20%14%9%
2413
May1st to 15thDay
41%6%12%18%13%7%
2721
16th to endDay
35%7%10%23%19%2
2850
June1st to 15thDay
28%6%13%27%19%4
2653
16th to endDay
42%8%13%23%11%
2535
July1st to 15thDay
38%8%17%23%11%
2396
16th to endDay
32%7%21%32%5%
2519
August1st to 15thDay
24%8%21%35%9%
2364
16th to endDay
37%11%19%24%6%1
2371
September1st to 15thDay
48%10%13%13%10%1
2145
16th to endDay
42%9%12%15%14%4
2145
October1st to 15thDay
33%6%12%20%20%7%
2127
16th to endDay
29%48%17%24%16%
2080
November1st to 15thDay
42%5%9%16%17%9%
2058
16th to endDay
38%38%14%19%15%
1960
December1st to 15thDay
48%47%14%16%9%
1890
16th to endDay
48%37%15%14%9%
2016
January1st to 15thNight
42%37%13%16%15%
2717
16th to endNight
40%38%17%17%12%
2782
February1st to 15thNight
42%49%13%14%15%
2472
16th to endNight
39%48%19%17%10%
2189
March1st to 15thNight
41%5%11%15%15%10%
2310
16th to endNight
37%413%17%16%10%
2464
April1st to 15thNight
38%5%12%16%16%11%
2307
16th to endNight
40%5%10%18%13%10%
2145
May1st to 15thNight
37%6%14%19%12%8%
1890
16th to endNight
31%8%14%27%15%1
1973
June1st to 15thNight
19%7%17%31%21%2
1836
16th to endNight
28%9%18%31%12%
1755
July1st to 15thNight
22%10%24%33%8%
1665
16th to endNight
16%8%32%34%7%
1738
August1st to 15thNight
12%6%28%44%7%
1821
16th to endNight
23%10%28%29%7%
2180
September1st to 15thNight
32%9%22%23%10%2
2145
16th to endNight
35%7%14%23%13%4
2145
October1st to 15thNight
20%6%14%30%19%8%
2148
16th to endNight
25%36%19%26%18%
2496
November1st to 15thNight
32%6%15%20%16%8%
2460
16th to endNight
31%5%9%19%17%16%
2658
December1st to 15thNight
43%48%16%18%9%
2730
16th to endNight
47%36%15%15%11%
2912

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
22%331%25%12%3
180
16th to endDay
22%7%35%17%15%2
192
February1st to 15thDay
26%5%29%25%10%3
180
16th to endDay
24%9%37%22%5%
159
March1st to 15thDay
28%431%26%10%
180
16th to endDay
16%333%40%6%
192
April1st to 15thDay
12%6%38%27%13%1
180
16th to endDay
15%9%36%28%9%
305
May1st to 15thDay
12%7%41%27%10%
618
16th to endDay
9%433%34%16%1
677
June1st to 15thDay
5%10%45%31%5%
616
16th to endDay
10%10%38%30%9%
570
July1st to 15thDay
5%17%38%37%9%
550
16th to endDay
5%5%35%41%11%
595
August1st to 15thDay
25%39%34%16%
443
16th to endDay
7%8%37%30%16%
283
September1st to 15thDay
17%417%41%18%
180
16th to endDay
6%6%21%40%25%
180
October1st to 15thDay
5%324%41%23%
180
16th to endDay
23%115%28%22%8%
192
November1st to 15thDay
23%5%20%24%24%2
180
16th to endDay
22%421%25%18%7%
180
December1st to 15thDay
30%419%23%13%7%
180
16th to endDay
31%7%29%20%8%2
192
January1st to 15thNight
23%5%26%31%12%
1050
16th to endNight
19%5%28%37%9%
990
February1st to 15thNight
22%8%27%34%7%
824
16th to endNight
20%7%40%26%4
719
March1st to 15thNight
20%5%33%34%5%
630
16th to endNight
14%5%38%35%5%
672
April1st to 15thNight
14%441%31%7%
629
16th to endNight
17%5%40%29%7%
624
May1st to 15thNight
13%340%38%4
630
16th to endNight
9%132%42%14%
659
June1st to 15thNight
414%55%23%1
612
16th to endNight
5%13%49%27%3
585
July1st to 15thNight
5%6%48%37%1
555
16th to endNight
2346%43%2
612
August1st to 15thNight
2245%45%4
575
16th to endNight
5%334%50%5%
621
September1st to 15thNight
8%229%49%8%
585
16th to endNight
12%431%43%7%
582
October1st to 15thNight
6%7%34%46%4
588
16th to endNight
9%218%39%26%1
832
November1st to 15thNight
13%220%39%22%1
820
16th to endNight
14%323%35%21%2
978
December1st to 15thNight
23%421%36%12%1
1050
16th to endNight
24%6%26%31%11%
1120
Page generated at 2019-06-10 18:29:50. Version ac04

Copyright 2019 A. Danko


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