Log Hill Mesa
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Log Hill Mesa clear sky chart from 2005-11-06 to 2024-02-05.

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
51%
24470
24%
79580
18%
24369
59%
24369
32%
45421

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 10thNight
47%
816
18%
4166
19%
798
55%
798
17%
2565
January11th to 20thNight
46%
758
20%
4048
22%
740
55%
740
16%
2541
January21st to endNight
48%
829
18%
4279
24%
814
54%
814
19%
2479
February1st to 10thNight
38%
738
21%
2398
16%
738
46%
738
25%
1472
February11th to 20thNight
35%
701
21%
2238
14%
700
45%
700
27%
1344
February21st to endNight
31%
592
27%
1773
12%
592
46%
592
27%
1100
March1st to 10thNight
37%
720
23%
1980
12%
720
47%
720
30%
1215
March11th to 20thNight
47%
720
24%
1980
15%
720
53%
720
36%
1192
March21st to endNight
38%
788
21%
2174
10%
788
47%
788
28%
1391
April1st to 10thNight
33%
540
21%
1800
14%
540
43%
540
26%
1070
April11th to 20thNight
34%
533
20%
1777
13%
533
45%
533
23%
1073
April21st to endNight
42%
540
21%
1800
14%
540
52%
540
26%
1048
May1st to 10thNight
43%
540
23%
1659
14%
540
53%
540
32%
946
May11th to 20thNight
54%
531
24%
1573
17%
531
61%
531
35%
877
May21st to endNight
50%
583
25%
1552
15%
582
58%
582
41%
860
June1st to 10thNight
61%
540
32%
1440
21%
540
68%
540
54%
722
June11th to 20thNight
60%
540
32%
1440
20%
540
68%
540
53%
721
June21st to endNight
69%
540
29%
1440
22%
540
75%
540
57%
716
July1st to 10thNight
73%
525
22%
1410
17%
525
76%
525
43%
804
July11th to 20thNight
77%
522
19%
1566
17%
522
79%
522
36%
878
July21st to endNight
77%
591
14%
1674
13%
558
78%
558
26%
1086
August1st to 10thNight
75%
537
17%
1602
15%
534
76%
534
35%
905
August11th to 20thNight
77%
534
24%
1664
22%
534
79%
534
40%
894
August21st to endNight
74%
594
25%
1980
28%
594
76%
594
39%
1055
September1st to 10thNight
73%
540
29%
1800
28%
540
79%
540
39%
938
September11th to 20thNight
68%
550
34%
1810
28%
550
76%
550
43%
905
September21st to endNight
66%
720
34%
2058
23%
720
73%
720
52%
1019
October1st to 10thNight
55%
720
27%
2160
18%
720
62%
720
42%
1131
October11th to 20thNight
57%
720
35%
2160
20%
720
68%
720
51%
1035
October21st to endNight
55%
792
35%
2376
22%
792
64%
792
42%
1244
November1st to 10thNight
54%
740
32%
2220
20%
740
64%
740
43%
1126
November11th to 20thNight
48%
950
33%
2496
18%
950
57%
950
45%
1382
November21st to endNight
48%
950
26%
2660
17%
950
54%
950
37%
1541
December1st to 10thNight
45%
950
22%
2660
13%
950
51%
950
34%
1600
December11th to 20thNight
40%
949
22%
3114
13%
948
46%
948
24%
1931
December21st to endNight
34%
1037
12%
4653
10%
1026
40%
1026
17%
2615

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
37%36%5%35%5%6%7%49%
78407
Night
27%36%43445%7%54%
80507
TransparencyDay
35%8%11%19%20%8%
78127
Night
30%7%12%22%22%8%
80308
SeeingDay
9%18%31%27%12%2
14208
Night
6%11%27%34%19%3
24498

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 10thDay
18%413%8%3446%6%43%
2771
11th to 20thDay
210%5%8%8%35%46%7%42%
2860
21st to endDay
210%5%9%5%34445%48%
3146
February1st to 10thDay
313%5%9%6%25%45%6%42%
1656
11th to 20thDay
310%48%6%35%45%8%44%
1607
21st to endDay
110%7%9%7%3445%6%43%
1480
March1st to 10thDay
311%48%43446%7%46%
1980
11th to 20thDay
28%46%7%35%6%6%7%49%
1980
21st to endDay
110%5%8%6%36%7%6%9%40%
2180
April1st to 10thDay
39%37%425%5%6%7%49%
2160
11th to 20thDay
311%46%5%45%6%6%8%43%
2131
21st to endDay
410%36%5%3445%9%47%
2160
May1st to 10thDay
5%7%36%6%45%7%6%7%44%
2297
11th to 20thDay
46%26%6%45%6%6%10%45%
2318
21st to endDay
45%25%5%45%5%6%8%52%
2724
June1st to 10thDay
2324435%5%6%7%60%
2520
11th to 20thDay
321442346%7%63%
2520
21st to endDay
2314435%5%5%8%60%
2520
July1st to 10thDay
4425%5%46%7%7%7%48%
2504
11th to 20thDay
3425%6%48%9%9%10%40%
2340
21st to endDay
8%5%47%7%5%8%8%8%8%31%
2545
August1st to 10thDay
7%5%36%7%5%6%7%7%8%38%
2328
11th to 20thDay
6%5%26%6%46%6%8%8%44%
2237
21st to endDay
4426%7%47%6%7%9%43%
2376
September1st to 10thDay
6%426%6%45%5%47%50%
2160
11th to 20thDay
5%3245%35%5%6%7%54%
2146
21st to endDay
5%4245%24345%62%
1901
October1st to 10thDay
6%4245%2445%6%58%
1800
11th to 20thDay
4323422346%67%
1800
21st to endDay
47%23423345%62%
1980
November1st to 10thDay
15%13322346%68%
1838
11th to 20thDay
27%2433345%5%63%
1682
21st to endDay
25%48%334435%59%
1520
December1st to 10thDay
29%47%6%3345%5%52%
1520
11th to 20thDay
29%5%9%5%35%5%5%7%45%
1926
21st to endDay
18%49%7%35%45%5%49%
2794
January1st to 10thNight
9%6%15%7%45%445%42%
4211
11th to 20thNight
112%5%7%7%5%6%5%47%42%
4110
21st to endNight
211%6%9%5%34446%47%
4521
February1st to 10thNight
211%6%8%5%34436%50%
2398
11th to 20thNight
37%48%6%35%45%7%48%
2237
21st to endNight
210%47%7%3445%5%48%
1773
March1st to 10thNight
18%45%5%25%5%5%8%52%
1980
11th to 20thNight
28%36%425%5%5%6%55%
1980
21st to endNight
210%46%445%46%7%49%
2174
April1st to 10thNight
47%46%4345%7%7%49%
1800
11th to 20thNight
211%45%435%6%6%8%47%
1777
21st to endNight
48%35%4245%6%7%51%
1800
May1st to 10thNight
35%245%25%5%6%8%54%
1659
11th to 20thNight
45%1333446%9%58%
1573
21st to endNight
3312335%5%6%8%61%
1552
June1st to 10thNight
221232345%8%69%
1440
11th to 20thNight
221222435%6%72%
1440
21st to endNight
11123245%6%8%66%
1440
July1st to 10thNight
2213325%6%8%10%57%
1450
11th to 20thNight
22145%36%6%8%12%53%
1620
21st to endNight
3315%5%5%7%8%9%14%40%
1773
August1st to 10thNight
3223435%6%7%9%55%
1611
11th to 20thNight
3224425%5%7%8%57%
1664
21st to endNight
33144345%6%9%57%
1980
September1st to 10thNight
33134245%6%10%58%
1800
11th to 20thNight
3213335%5%6%7%63%
1810
21st to endNight
431332233472%
2058
October1st to 10thNight
5%413324348%63%
2160
11th to 20thNight
3312313345%73%
2160
21st to endNight
48%2432333466%
2376
November1st to 10thNight
25%1222345%7%66%
2220
11th to 20thNight
37%23423345%64%
2496
21st to endNight
28%46%323347%58%
2660
December1st to 10thNight
28%36%424446%55%
2660
11th to 20thNight
27%47%6%35%6%6%7%46%
3271
21st to endNight
28%5%9%7%34445%49%
4873

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 10thDay
42%6%15%18%16%3
2772
11th to 20thDay
44%6%16%21%11%2
2860
21st to endDay
41%5%9%25%16%4
3146
February1st to 10thDay
43%7%14%16%14%5%
1656
11th to 20thDay
41%6%9%20%19%5%
1616
21st to endDay
45%5%7%18%19%5%
1480
March1st to 10thDay
40%7%10%19%20%3
1980
11th to 20thDay
35%7%14%26%14%4
1980
21st to endDay
44%9%10%21%14%3
2180
April1st to 10thDay
36%8%10%21%18%6%
2160
11th to 20thDay
41%8%10%19%19%4
2134
21st to endDay
38%8%11%24%17%2
2160
May1st to 10thDay
40%8%9%20%21%2
2297
11th to 20thDay
37%9%12%23%15%3
2321
21st to endDay
31%7%10%20%24%7%
2724
June1st to 10thDay
24%7%11%22%25%12%
2520
11th to 20thDay
22%5%9%15%27%22%
2520
21st to endDay
25%6%10%15%23%22%
2520
July1st to 10thDay
35%9%11%12%17%16%
2435
11th to 20thDay
38%14%15%14%10%9%
2271
21st to endDay
48%15%14%10%10%3
2404
August1st to 10thDay
46%12%10%11%12%9%
2313
11th to 20thDay
40%10%12%11%18%9%
2237
21st to endDay
39%11%10%17%17%6%
2376
September1st to 10thDay
37%7%9%13%20%14%
2160
11th to 20thDay
31%9%10%14%25%11%
2146
21st to endDay
27%5%8%20%30%10%
1901
October1st to 10thDay
31%6%10%21%24%9%
1800
11th to 20thDay
21%47%24%34%10%
1800
21st to endDay
27%5%8%27%26%6%
1980
November1st to 10thDay
20%5%11%25%32%7%
1838
11th to 20thDay
24%5%10%31%26%6%
1682
21st to endDay
28%6%9%25%21%11%
1520
December1st to 10thDay
35%8%12%24%16%5%
1520
11th to 20thDay
40%7%10%18%23%3
1924
21st to endDay
34%6%12%17%20%11%
2794
January1st to 10thNight
44%5%12%20%15%4
4211
11th to 20thNight
44%7%13%22%13%2
4110
21st to endNight
38%6%8%28%16%3
4521
February1st to 10thNight
38%6%12%20%18%6%
2398
11th to 20thNight
36%6%11%22%18%7%
2238
21st to endNight
38%5%11%20%23%5%
1773
March1st to 10thNight
31%8%10%21%26%4
1980
11th to 20thNight
31%6%12%28%19%3
1980
21st to endNight
36%7%13%24%17%3
2174
April1st to 10thNight
33%8%12%21%20%5%
1800
11th to 20thNight
36%8%12%20%21%4
1777
21st to endNight
33%8%12%26%19%2
1800
May1st to 10thNight
28%9%11%27%22%3
1659
11th to 20thNight
26%9%14%30%20%3
1574
21st to endNight
21%8%14%23%26%8%
1552
June1st to 10thNight
14%7%10%25%33%12%
1440
11th to 20thNight
14%6%8%17%29%26%
1440
21st to endNight
15%6%10%17%28%24%
1440
July1st to 10thNight
22%11%14%14%20%20%
1410
11th to 20thNight
25%11%19%19%14%12%
1566
21st to endNight
33%15%22%17%8%4
1674
August1st to 10thNight
24%12%19%17%17%11%
1602
11th to 20thNight
23%9%18%16%21%12%
1664
21st to endNight
23%10%15%21%22%9%
1980
September1st to 10thNight
23%8%13%16%25%15%
1800
11th to 20thNight
20%8%14%19%27%13%
1810
21st to endNight
17%5%8%25%35%10%
2058
October1st to 10thNight
23%5%12%22%27%11%
2160
11th to 20thNight
16%5%9%23%35%11%
2160
21st to endNight
24%48%29%26%8%
2376
November1st to 10thNight
19%7%12%25%28%9%
2220
11th to 20thNight
23%5%10%28%28%6%
2496
21st to endNight
29%5%8%22%24%11%
2660
December1st to 10thNight
31%7%13%21%21%7%
2660
11th to 20thNight
34%9%10%20%23%3
3272
21st to endNight
37%7%9%16%22%9%
4873

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 10thDay
12%18%29%27%12%2
270
11th to 20thDay
12%23%32%23%10%
270
21st to endDay
417%39%28%9%2
297
February1st to 10thDay
14%27%33%22%31
252
11th to 20thDay
15%32%33%15%5%
240
21st to endDay
19%29%29%19%4
198
March1st to 10thDay
16%33%29%18%3
420
11th to 20thDay
11%30%31%21%6%
420
21st to endDay
17%36%31%14%2
462
April1st to 10thDay
15%29%34%16%41
420
11th to 20thDay
19%33%31%12%4
412
21st to endDay
14%32%34%15%5%
420
May1st to 10thDay
14%28%36%15%5%
423
11th to 20thDay
10%22%34%24%8%2
465
21st to endDay
10%21%32%23%12%3
679
June1st to 10thDay
6%11%31%32%17%3
630
11th to 20thDay
6%14%35%29%13%4
630
21st to endDay
312%34%30%17%3
630
July1st to 10thDay
35%22%40%25%4
605
11th to 20thDay
5%425%38%21%7%
444
21st to endDay
6%323%39%22%6%
487
August1st to 10thDay
8%6%28%37%16%5%
447
11th to 20thDay
5%432%37%17%5%
437
21st to endDay
35%32%37%18%4
495
September1st to 10thDay
9%9%28%33%17%3
450
11th to 20thDay
5%13%40%30%11%2
450
21st to endDay
7%18%30%29%12%4
371
October1st to 10thDay
10%21%24%25%17%4
270
11th to 20thDay
420%31%26%16%2
270
21st to endDay
8%20%33%28%11%1
297
November1st to 10thDay
11%28%24%26%10%1
270
11th to 20thDay
5%21%32%24%15%2
270
21st to endDay
8%21%29%27%13%2
270
December1st to 10thDay
9%25%33%22%11%1
270
11th to 20thDay
11%19%30%27%10%2
270
21st to endDay
17%20%33%22%8%1
297
January1st to 10thNight
7%11%29%32%16%5%
822
11th to 20thNight
7%13%30%30%16%3
760
21st to endNight
6%10%31%35%15%4
836
February1st to 10thNight
9%13%35%31%9%2
738
11th to 20thNight
7%15%38%28%11%1
704
21st to endNight
8%15%41%28%7%
592
March1st to 10thNight
8%19%33%29%10%2
720
11th to 20thNight
5%12%31%33%18%1
720
21st to endNight
7%19%33%29%10%1
788
April1st to 10thNight
10%16%37%30%7%1
540
11th to 20thNight
9%20%33%28%10%1
533
21st to endNight
10%17%30%28%14%2
540
May1st to 10thNight
6%12%35%34%13%1
540
11th to 20thNight
8%8%27%36%18%3
531
21st to endNight
6%12%29%33%18%2
584
June1st to 10thNight
37%25%36%26%2
540
11th to 20thNight
210%25%42%18%3
540
21st to endNight
1321%42%28%3
540
July1st to 10thNight
3116%39%38%3
525
11th to 20thNight
229%40%41%6%
522
21st to endNight
329%35%46%5%
591
August1st to 10thNight
4211%38%39%6%
537
11th to 20thNight
3211%41%37%5%
534
21st to endNight
3214%41%32%7%
594
September1st to 10thNight
3316%44%32%3
540
11th to 20thNight
3421%38%30%5%
550
21st to endNight
48%19%36%24%9%
720
October1st to 10thNight
6%11%25%37%18%2
720
11th to 20thNight
39%28%33%21%5%
720
21st to endNight
9%9%25%32%20%5%
792
November1st to 10thNight
6%12%26%33%19%4
740
11th to 20thNight
7%12%29%31%16%3
950
21st to endNight
8%13%28%32%15%3
950
December1st to 10thNight
7%14%31%33%12%2
950
11th to 20thNight
8%17%29%29%16%1
950
21st to endNight
10%13%36%32%8%1
1045
Page generated at 2024-02-02 03:20:27. Version ac07

Copyright 2024 Attilla Danko


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