Lake City
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake City clear sky chart from 2005-11-05 to 2017-08-12.

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
50%
15717
26%
46544
17%
15674
58%
15674
38%
25139

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
49%
778
27%
2386
21%
775
57%
775
44%
1170
January16th to endNight
47%
768
30%
2496
25%
768
56%
768
39%
1274
February1st to 15thNight
42%
697
22%
2288
16%
696
51%
696
35%
1204
February16th to endNight
34%
632
32%
1911
15%
632
53%
632
37%
1002
March1st to 15thNight
40%
720
27%
1999
13%
720
51%
720
40%
1080
March16th to endNight
40%
750
26%
2094
14%
750
49%
750
37%
1169
April1st to 15thNight
30%
539
20%
1798
11%
539
42%
539
27%
990
April16th to endNight
34%
540
25%
1800
14%
540
49%
540
31%
944
May1st to 15thNight
42%
540
22%
1673
15%
539
51%
539
33%
929
May16th to endNight
44%
563
25%
1516
12%
561
54%
561
40%
818
June1st to 15thNight
57%
540
28%
1440
17%
540
65%
540
55%
702
June16th to endNight
68%
540
29%
1440
22%
540
73%
540
56%
709
July1st to 15thNight
70%
510
15%
1397
12%
510
71%
510
30%
888
July16th to endNight
74%
564
12%
1593
12%
531
75%
531
28%
1003
August1st to 15thNight
73%
527
15%
1578
14%
524
75%
524
30%
952
August16th to endNight
70%
525
21%
1750
21%
525
73%
525
30%
1023
September1st to 15thNight
67%
495
25%
1650
23%
495
73%
495
32%
934
September16th to endNight
65%
584
34%
1803
25%
584
73%
584
48%
868
October1st to 15thNight
51%
660
30%
1980
18%
660
60%
660
43%
1006
October16th to endNight
56%
704
35%
2112
22%
704
66%
704
46%
1060
November1st to 15thNight
50%
781
31%
2181
20%
781
57%
781
44%
1129
November16th to endNight
49%
900
31%
2451
20%
900
56%
900
47%
1276
December1st to 15thNight
37%
900
20%
2520
9%
900
46%
900
40%
1382
December16th to endNight
37%
960
24%
2688
14%
960
45%
960
32%
1627

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
46%48%6%35%45%6%43%
47427
Night
1325%5%35%5%6%8%54%
46733
TransparencyDay
39%411%21%17%5%
47115
Night
24%6%15%26%21%5%
46546
SeeingDay
14%22%25%22%12%2
5537
Night
412%27%30%20%3
15726

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
238%6%36%5%5%7%51%
1561
16th to endDay
438%7%23345%54%
1728
February1st to 15thDay
3411%7%345%6%6%46%
1575
16th to endDay
4310%7%45%5%6%7%43%
1563
March1st to 15thDay
6%49%7%35%45%7%45%
1959
16th to endDay
17%6%9%6%3445%7%42%
2129
April1st to 15thDay
19%5%9%6%445%45%42%
2150
16th to endDay
111%6%8%6%35%5%5%6%39%
2160
May1st to 15thDay
311%48%7%45%5%5%7%36%
2274
16th to endDay
5%8%47%6%3445%6%44%
2595
June1st to 15thDay
45%35%5%2445%7%51%
2520
16th to endDay
3435%6%34446%53%
2520
July1st to 15thDay
11%7%48%8%46%6%5%6%30%
2477
16th to endDay
12%9%5%10%9%5%7%5%5%6%22%
2467
August1st to 15thDay
15%8%5%10%9%45%44426%
2287
16th to endDay
10%8%410%9%45%5%5%5%29%
2100
September1st to 15thDay
10%9%38%7%35%45%435%
1980
16th to endDay
6%6%37%6%3333450%
1824
October1st to 15thDay
5%8%25%433445%51%
1650
16th to endDay
36%35%32334459%
1760
November1st to 15thDay
325%42335%5%61%
1665
16th to endDay
316%413335%65%
1507
December1st to 15thDay
445%7%4436%7%51%
1440
16th to endDay
439%7%45%5%6%9%44%
1536
January1st to 15thNight
1145%25%5%5%8%59%
2386
16th to endNight
125%7%35%5%5%7%55%
2496
February1st to 15thNight
226%7%445%5%8%53%
2277
16th to endNight
136%6%35%5%6%9%52%
1911
March1st to 15thNight
226%4345%6%8%54%
1999
16th to endNight
335%5%35%5%5%7%53%
2094
April1st to 15thNight
426%6%45%46%8%48%
1798
16th to endNight
16%26%5%33448%52%
1800
May1st to 15thNight
15%25%436%46%8%51%
1673
16th to endNight
332432346%10%55%
1516
June1st to 15thNight
221221435%7%67%
1440
16th to endNight
1212225%35%7%65%
1440
July1st to 15thNight
33246%46%8%7%10%42%
1480
16th to endNight
42246%37%7%9%11%38%
1701
August1st to 15thNight
5%424425%6%6%10%47%
1587
16th to endNight
6%425%4345%6%10%45%
1750
September1st to 15thNight
4315%5%35%6%7%9%47%
1650
16th to endNight
2313322347%65%
1803
October1st to 15thNight
341322445%8%61%
1980
16th to endNight
1424422335%64%
2112
November1st to 15thNight
314325%5%5%7%59%
2181
16th to endNight
22342445%6%62%
2451
December1st to 15thNight
225%5%35%46%8%56%
2520
16th to endNight
226%7%46%6%7%8%46%
2688

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
29%421%27%13%2
1562
16th to endDay
29%413%27%18%5%
1728
February1st to 15thDay
33%418%24%14%5%
1575
16th to endDay
35%410%26%18%4
1563
March1st to 15thDay
36%314%26%16%2
1959
16th to endDay
39%411%26%15%2
2129
April1st to 15thDay
40%411%24%14%4
2150
16th to endDay
41%411%26%13%1
2160
May1st to 15thDay
46%310%24%14%
2274
16th to endDay
39%410%24%17%3
2598
June1st to 15thDay
30%39%20%24%11%
2520
16th to endDay
31%35%16%28%14%
2520
July1st to 15thDay
53%6%9%10%13%7%
2331
16th to endDay
60%7%14%9%7%1
2312
August1st to 15thDay
59%6%8%9%11%4
2272
16th to endDay
54%412%15%11%1
2100
September1st to 15thDay
50%49%12%18%5%
1980
16th to endDay
37%36%22%25%4
1824
October1st to 15thDay
34%35%26%23%6%
1650
16th to endDay
27%38%28%27%4
1760
November1st to 15thDay
22%412%24%27%8%
1665
16th to endDay
20%212%33%23%8%
1507
December1st to 15thDay
29%5%20%26%15%2
1440
16th to endDay
34%8%17%22%13%3
1536
January1st to 15thNight
19%421%29%20%3
2386
16th to endNight
23%5%13%29%21%6%
2496
February1st to 15thNight
27%418%26%17%5%
2288
16th to endNight
23%5%12%31%22%5%
1911
March1st to 15thNight
23%5%17%28%22%2
1999
16th to endNight
25%5%14%31%19%3
2094
April1st to 15thNight
29%5%17%26%17%4
1798
16th to endNight
27%416%31%17%2
1800
May1st to 15thNight
28%5%15%31%17%1
1674
16th to endNight
23%416%33%19%3
1517
June1st to 15thNight
15%312%26%30%12%
1440
16th to endNight
16%38%22%32%16%
1440
July1st to 15thNight
33%10%16%13%17%8%
1397
16th to endNight
31%13%26%15%9%3
1593
August1st to 15thNight
31%10%18%17%16%6%
1578
16th to endNight
32%7%17%24%15%2
1750
September1st to 15thNight
29%8%17%17%22%5%
1650
16th to endNight
18%310%33%28%4
1803
October1st to 15thNight
21%411%29%25%7%
1980
16th to endNight
21%39%30%30%5%
2112
November1st to 15thNight
20%5%13%24%29%7%
2181
16th to endNight
19%411%31%25%8%
2451
December1st to 15thNight
22%6%22%24%20%3
2520
16th to endNight
29%8%16%25%14%4
2688

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
11%17%31%25%14%
90
16th to endDay
8%21%29%31%9%
96
February1st to 15thDay
10%33%27%20%8%
90
16th to endDay
12%35%17%22%12%
81
March1st to 15thDay
14%36%24%22%2
249
16th to endDay
21%37%26%11%2
288
April1st to 15thDay
18%37%27%11%31
269
16th to endDay
20%39%26%10%3
270
May1st to 15thDay
12%39%29%13%4
288
16th to endDay
13%26%25%18%12%3
496
June1st to 15thDay
7%19%29%22%16%3
495
16th to endDay
314%23%26%24%7%
495
July1st to 15thDay
14%7%17%31%21%6%
435
16th to endDay
21%8%17%32%16%3
327
August1st to 15thDay
21%8%22%29%14%4
300
16th to endDay
17%10%25%33%10%2
268
September1st to 15thDay
18%17%33%21%6%1
255
16th to endDay
14%12%34%23%9%4
193
October1st to 15thDay
7%18%28%20%17%6%
90
16th to endDay
19%12%31%18%17%
96
November1st to 15thDay
6%18%18%27%24%3
90
16th to endDay
11%37%32%11%7%
90
December1st to 15thDay
11%36%32%20%
90
16th to endDay
6%33%20%30%8%1
96
January1st to 15thNight
412%30%33%15%3
780
16th to endNight
212%34%32%14%4
768
February1st to 15thNight
311%36%36%10%
704
16th to endNight
417%39%30%8%
632
March1st to 15thNight
217%34%29%13%2
720
16th to endNight
318%34%29%13%1
750
April1st to 15thNight
326%35%26%7%
539
16th to endNight
5%19%35%24%13%1
540
May1st to 15thNight
412%33%34%13%1
540
16th to endNight
6%14%29%25%20%3
563
June1st to 15thNight
212%23%33%25%2
540
16th to endNight
25%17%36%32%5%
540
July1st to 15thNight
5%37%35%43%5%
510
16th to endNight
5%1227%50%12%
564
August1st to 15thNight
6%3429%49%6%
527
16th to endNight
7%38%28%41%10%
525
September1st to 15thNight
5%313%37%34%5%
495
16th to endNight
48%17%26%32%10%
584
October1st to 15thNight
5%14%24%31%18%5%
660
16th to endNight
311%23%34%22%5%
704
November1st to 15thNight
414%26%31%20%2
781
16th to endNight
414%29%30%16%4
900
December1st to 15thNight
318%38%28%9%2
900
16th to endNight
5%15%37%30%10%1
960
Page generated at 2017-08-13 12:16:13. Version ac04

Copyright 2017 A. Danko


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