Steamboat Lake State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Steamboat Lake State Park clear sky chart from 2005-11-06 to 2024-01-12.

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
44%
24618
20%
74454
15%
24572
50%
24572
28%
46338

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
33%
947
15%
2647
10%
946
36%
946
20%
1902
January11th to 20thNight
29%
802
18%
2431
12%
802
35%
802
20%
1699
January21st to endNight
28%
792
15%
2574
11%
792
34%
792
17%
1849
February1st to 10thNight
20%
720
10%
2340
7%
720
25%
720
12%
1784
February11th to 20thNight
26%
700
12%
2241
7%
700
32%
700
16%
1598
February21st to endNight
22%
592
17%
1776
7%
592
32%
592
17%
1281
March1st to 10thNight
33%
720
19%
2068
10%
720
42%
720
26%
1368
March11th to 20thNight
45%
720
23%
1980
15%
720
51%
720
33%
1239
March21st to endNight
34%
738
15%
2124
8%
738
40%
738
22%
1480
April1st to 10thNight
36%
540
16%
1800
11%
540
44%
540
23%
1134
April11th to 20thNight
34%
533
17%
1777
13%
533
42%
533
22%
1131
April21st to endNight
45%
540
19%
1800
15%
540
52%
540
26%
1077
May1st to 10thNight
41%
540
18%
1601
12%
540
46%
540
25%
1060
May11th to 20thNight
59%
531
19%
1418
16%
531
61%
531
33%
904
May21st to endNight
52%
584
20%
1552
13%
582
57%
582
33%
975
June1st to 10thNight
59%
540
23%
1440
17%
540
62%
540
43%
802
June11th to 20thNight
52%
540
25%
1440
17%
540
58%
540
42%
820
June21st to endNight
69%
540
29%
1440
24%
540
73%
540
57%
725
July1st to 10thNight
74%
525
22%
1400
20%
525
76%
525
46%
791
July11th to 20thNight
78%
522
26%
1392
23%
522
79%
522
53%
728
July21st to endNight
77%
591
22%
1622
20%
558
77%
558
42%
885
August1st to 10thNight
75%
537
23%
1602
21%
534
75%
534
41%
871
August11th to 20thNight
76%
534
31%
1651
30%
534
78%
534
46%
836
August21st to endNight
76%
594
31%
1980
33%
594
78%
594
43%
994
September1st to 10thNight
72%
540
33%
1800
33%
540
79%
540
47%
853
September11th to 20thNight
67%
540
33%
1800
32%
540
72%
540
41%
914
September21st to endNight
63%
664
33%
2040
25%
664
70%
664
50%
1000
October1st to 10thNight
52%
720
27%
2160
18%
720
59%
720
36%
1234
October11th to 20thNight
50%
720
31%
2160
18%
720
59%
720
39%
1179
October21st to endNight
43%
792
25%
2376
15%
792
51%
792
33%
1408
November1st to 10thNight
39%
889
23%
2369
12%
889
46%
889
34%
1480
November11th to 20thNight
32%
950
22%
2546
9%
950
40%
950
28%
1657
November21st to endNight
36%
950
20%
2660
11%
950
43%
950
29%
1709
December1st to 10thNight
27%
950
13%
2660
7%
950
32%
950
21%
1872
December11th to 20thNight
27%
948
17%
3088
8%
948
32%
948
18%
2014
December21st to endNight
19%
1033
8%
4699
4%
1026
25%
1026
9%
3085

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
6%11%48%5%3445%7%43%
74731
Night
5%11%5%7%5%3445%7%45%
75001
TransparencyDay
40%5%11%22%17%6%
74443
Night
38%5%12%23%16%6%
74812
SeeingDay
14%17%31%24%12%3
14437
Night
12%9%27%35%15%2
24639

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
5%19%7%11%6%3235%6%35%
1518
11th to 20thDay
318%10%12%6%3345%433%
1567
21st to endDay
318%10%15%7%23345%30%
1782
February1st to 10thDay
5%22%9%13%8%33236%26%
1620
11th to 20thDay
5%19%11%13%8%2333429%
1607
21st to endDay
317%9%18%9%3344425%
1480
March1st to 10thDay
416%7%13%7%23346%35%
1890
11th to 20thDay
312%7%9%5%3445%7%40%
1980
21st to endDay
5%18%7%11%8%35%5%5%7%27%
2232
April1st to 10thDay
6%18%5%8%5%35%45%6%35%
2160
11th to 20thDay
7%17%6%9%6%345%5%7%30%
2131
21st to endDay
6%15%5%7%5%345%6%8%37%
2160
May1st to 10thDay
9%13%48%6%35%6%6%8%32%
2354
11th to 20thDay
8%10%25%6%5%6%7%8%9%35%
2478
21st to endDay
8%9%36%6%35%5%6%9%38%
2724
June1st to 10thDay
6%5%245%35%5%6%8%51%
2520
11th to 20thDay
6%3244245%5%8%57%
2520
21st to endDay
33144345%6%7%61%
2520
July1st to 10thDay
5%324435%6%6%9%53%
2520
11th to 20thDay
4426%5%36%5%7%9%50%
2520
21st to endDay
6%5%25%6%46%6%7%9%44%
2598
August1st to 10thDay
6%6%35%6%47%7%7%8%42%
2328
11th to 20thDay
44146%45%5%6%7%52%
2250
21st to endDay
5%425%6%35%5%6%7%52%
2376
September1st to 10thDay
6%425%42445%5%60%
2160
11th to 20thDay
8%6%2443345%5%56%
2160
21st to endDay
7%5%24333445%60%
1917
October1st to 10thDay
9%10%35%43344450%
1800
11th to 20thDay
10%10%3332335%6%53%
1800
21st to endDay
7%13%45%223347%49%
1980
November1st to 10thDay
6%12%5%6%323447%47%
1689
11th to 20thDay
6%17%5%7%5%23345%42%
1630
21st to endDay
413%5%12%422336%47%
1520
December1st to 10thDay
5%18%7%14%5%34345%33%
1520
11th to 20thDay
5%18%7%10%6%33346%36%
1926
21st to endDay
317%8%14%7%335%46%30%
2794
January1st to 10thNight
418%7%12%6%34345%35%
2647
11th to 20thNight
318%9%11%6%4323437%
2431
21st to endNight
318%11%14%6%1323434%
2574
February1st to 10thNight
420%9%14%8%33336%27%
2340
11th to 20thNight
417%8%14%6%33345%32%
2240
21st to endNight
316%10%14%8%33346%32%
1776
March1st to 10thNight
414%6%10%6%2345%6%40%
2068
11th to 20thNight
312%5%6%435%45%7%46%
1980
21st to endNight
416%6%9%6%35%447%36%
2124
April1st to 10thNight
6%15%5%6%5%3445%5%42%
1800
11th to 20thNight
7%13%5%7%5%345%5%6%39%
1777
21st to endNight
6%13%45%5%3445%8%43%
1800
May1st to 10thNight
10%11%36%5%345%7%7%40%
1601
11th to 20thNight
7%9%34445%5%6%10%43%
1417
21st to endNight
7%7%25%5%45%6%6%7%47%
1552
June1st to 10thNight
5%4324345%7%10%54%
1440
11th to 20thNight
6%415%3246%5%6%58%
1440
21st to endNight
221242347%7%66%
1440
July1st to 10thNight
43134345%7%8%58%
1440
11th to 20thNight
33134345%6%10%59%
1440
21st to endNight
23245%47%6%7%9%52%
1717
August1st to 10thNight
44245%35%5%7%8%52%
1611
11th to 20thNight
332442346%10%58%
1651
21st to endNight
3314435%5%6%8%57%
1980
September1st to 10thNight
5%31332345%7%64%
1800
11th to 20thNight
7%5%23433346%59%
1800
21st to endNight
6%413222345%67%
2040
October1st to 10thNight
9%8%25%323445%56%
2160
11th to 20thNight
7%9%24223346%58%
2160
21st to endNight
7%12%45%422336%52%
2376
November1st to 10thNight
7%12%36%422346%51%
2369
11th to 20thNight
6%15%47%423346%45%
2546
21st to endNight
313%5%9%5%23447%44%
2660
December1st to 10thNight
5%19%6%10%6%32345%37%
2660
11th to 20thNight
415%7%10%6%2335%8%37%
3271
21st to endNight
314%8%11%8%4445%7%33%
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
51%6%17%17%8%2
1519
11th to 20thDay
54%414%18%8%2
1567
21st to endDay
59%316%14%7%2
1782
February1st to 10thDay
60%5%11%15%8%1
1620
11th to 20thDay
59%410%18%7%2
1616
21st to endDay
61%5%11%13%9%1
1480
March1st to 10thDay
50%412%24%9%
1890
11th to 20thDay
43%415%25%11%2
1980
21st to endDay
55%6%9%20%7%2
2232
April1st to 10thDay
47%6%13%16%14%4
2160
11th to 20thDay
51%5%11%19%12%1
2134
21st to endDay
44%5%10%30%10%
2160
May1st to 10thDay
47%6%10%22%13%1
2354
11th to 20thDay
41%6%16%25%10%1
2482
21st to endDay
42%6%10%26%15%2
2724
June1st to 10thDay
28%5%12%25%23%7%
2520
11th to 20thDay
25%5%8%19%29%16%
2520
21st to endDay
21%45%21%32%16%
2520
July1st to 10thDay
26%6%8%20%26%15%
2451
11th to 20thDay
28%5%11%21%20%16%
2445
21st to endDay
33%5%13%19%20%11%
2454
August1st to 10thDay
36%6%12%19%18%9%
2313
11th to 20thDay
29%310%20%25%12%
2250
21st to endDay
29%5%8%23%24%11%
2376
September1st to 10thDay
26%36%18%27%21%
2160
11th to 20thDay
28%5%8%23%24%12%
2160
21st to endDay
27%36%30%29%5%
1917
October1st to 10thDay
37%49%27%18%5%
1800
11th to 20thDay
32%49%31%19%5%
1800
21st to endDay
37%414%28%14%3
1980
November1st to 10thDay
37%6%11%28%18%1
1689
11th to 20thDay
44%415%22%14%1
1630
21st to endDay
41%314%27%13%1
1520
December1st to 10thDay
54%418%14%9%1
1520
11th to 20thDay
49%411%27%8%
1924
21st to endDay
53%6%7%18%14%2
2794
January1st to 10thNight
52%413%20%8%2
2647
11th to 20thNight
52%312%19%11%3
2431
21st to endNight
55%413%17%9%3
2574
February1st to 10thNight
59%7%10%16%8%1
2340
11th to 20thNight
54%5%11%19%9%2
2241
21st to endNight
53%5%10%18%11%3
1776
March1st to 10thNight
44%413%27%12%1
2068
11th to 20thNight
37%5%13%27%14%4
1980
21st to endNight
47%6%12%23%9%1
2124
April1st to 10thNight
41%6%14%19%16%5%
1800
11th to 20thNight
42%6%13%23%15%1
1777
21st to endNight
38%412%28%17%1
1800
May1st to 10thNight
40%8%12%25%13%2
1601
11th to 20thNight
35%7%18%27%11%3
1418
21st to endNight
34%6%11%29%17%3
1552
June1st to 10thNight
25%5%15%26%20%8%
1440
11th to 20thNight
25%6%10%18%24%17%
1440
21st to endNight
17%45%23%30%21%
1440
July1st to 10thNight
23%8%9%20%24%16%
1400
11th to 20thNight
19%6%13%24%21%18%
1392
21st to endNight
25%6%16%22%18%12%
1622
August1st to 10thNight
27%5%14%27%17%10%
1602
11th to 20thNight
22%5%11%20%27%15%
1651
21st to endNight
23%5%10%22%28%12%
1980
September1st to 10thNight
20%49%19%26%22%
1800
11th to 20thNight
26%310%22%25%14%
1800
21st to endNight
20%36%28%36%6%
2040
October1st to 10thNight
32%48%28%21%8%
2160
11th to 20thNight
28%48%34%22%5%
2160
21st to endNight
35%313%29%15%4
2376
November1st to 10thNight
35%5%12%26%21%2
2369
11th to 20thNight
40%414%26%13%3
2546
21st to endNight
40%5%10%29%15%2
2660
December1st to 10thNight
50%415%18%11%2
2660
11th to 20thNight
46%414%27%10%
3272
21st to endNight
50%7%10%16%15%2
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
20%16%31%20%11%1
270
11th to 20thDay
12%23%35%22%8%
243
21st to endDay
13%24%42%19%2
264
February1st to 10thDay
30%25%32%11%2
240
11th to 20thDay
22%25%33%18%3
240
21st to endDay
23%29%31%16%2
198
March1st to 10thDay
23%24%32%16%5%
330
11th to 20thDay
15%22%36%21%6%
420
21st to endDay
19%27%37%13%31
462
April1st to 10thDay
23%26%29%18%3
420
11th to 20thDay
23%28%30%15%31
412
21st to endDay
18%22%33%18%8%2
420
May1st to 10thDay
20%23%29%18%9%1
449
11th to 20thDay
15%14%27%27%15%2
625
21st to endDay
15%15%27%24%16%2
679
June1st to 10thDay
8%13%26%28%19%6%
630
11th to 20thDay
9%16%33%27%13%2
630
21st to endDay
5%11%32%32%16%3
630
July1st to 10thDay
7%422%36%25%5%
621
11th to 20thDay
6%6%26%33%23%6%
618
21st to endDay
7%7%23%34%24%6%
540
August1st to 10thDay
10%8%34%32%11%4
447
11th to 20thDay
5%9%33%33%15%5%
437
21st to endDay
7%10%32%30%18%4
495
September1st to 10thDay
8%13%30%27%17%4
450
11th to 20thDay
9%12%38%24%12%5%
450
21st to endDay
11%17%28%25%14%5%
333
October1st to 10thDay
15%17%26%25%11%6%
270
11th to 20thDay
18%18%30%24%9%2
270
21st to endDay
18%23%32%20%6%
297
November1st to 10thDay
20%22%28%21%8%
270
11th to 20thDay
17%23%31%24%41
270
21st to endDay
12%21%37%25%41
270
December1st to 10thDay
20%25%30%18%5%1
270
11th to 20thDay
17%21%40%17%5%
270
21st to endDay
23%20%34%16%6%1
297
January1st to 10thNight
15%14%29%31%10%1
950
11th to 20thNight
14%15%34%29%6%1
802
21st to endNight
14%11%38%31%6%1
792
February1st to 10thNight
18%12%40%24%6%
720
11th to 20thNight
14%15%32%33%6%
704
21st to endNight
13%18%39%27%4
592
March1st to 10thNight
14%12%34%30%9%1
720
11th to 20thNight
9%8%29%41%11%1
720
21st to endNight
11%12%34%32%10%1
738
April1st to 10thNight
15%12%31%36%6%
540
11th to 20thNight
15%13%33%29%9%2
533
21st to endNight
14%11%24%35%14%1
540
May1st to 10thNight
16%6%31%32%14%2
540
11th to 20thNight
12%418%45%18%3
531
21st to endNight
11%5%24%38%20%2
584
June1st to 10thNight
7%5%23%37%24%2
540
11th to 20thNight
9%7%26%42%16%1
540
21st to endNight
4319%44%29%2
540
July1st to 10thNight
5%212%39%39%3
525
11th to 20thNight
429%46%35%3
522
21st to endNight
237%42%43%4
591
August1st to 10thNight
6%27%48%35%2
537
11th to 20thNight
429%49%32%4
534
21st to endNight
4210%43%34%7%
594
September1st to 10thNight
6%216%42%28%5%
540
11th to 20thNight
9%314%43%27%4
540
21st to endNight
9%422%34%25%7%
664
October1st to 10thNight
12%6%25%34%19%3
720
11th to 20thNight
12%10%24%38%14%3
720
21st to endNight
15%10%28%33%12%2
792
November1st to 10thNight
13%12%31%32%11%1
889
11th to 20thNight
16%15%32%29%6%1
950
21st to endNight
12%11%33%35%8%
950
December1st to 10thNight
18%12%34%28%7%
950
11th to 20thNight
15%14%36%30%5%
950
21st to endNight
18%17%35%23%6%1
1045
Page generated at 2024-01-08 20:31:27. Version ac07

Copyright 2024 Attilla Danko


Steamboat Lake State Park Clear Sky Chart |Charts Home