Deerlodge Park Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Deerlodge Park Campground clear sky chart from 2005-11-06 to 2024-02-25.

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
60%
24703
21%
80386
19%
24630
64%
24630
30%
48807

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
55%
884
12%
4302
12%
875
58%
875
14%
3016
January11th to 20thNight
56%
752
15%
4084
16%
740
62%
740
14%
2614
January21st to endNight
49%
826
10%
4503
16%
814
53%
814
9%
3551
February1st to 10thNight
52%
760
16%
2470
14%
760
57%
760
24%
1580
February11th to 20thNight
50%
740
15%
2403
13%
740
54%
740
25%
1527
February21st to endNight
49%
610
21%
1858
16%
610
57%
610
28%
1170
March1st to 10thNight
53%
720
21%
1980
16%
720
57%
720
32%
1246
March11th to 20thNight
63%
720
22%
1980
18%
720
65%
720
35%
1208
March21st to endNight
53%
792
17%
2178
12%
792
57%
792
28%
1429
April1st to 10thNight
49%
555
18%
1815
16%
555
53%
555
26%
1093
April11th to 20thNight
48%
533
19%
1777
17%
533
53%
533
25%
1087
April21st to endNight
50%
540
20%
1711
16%
540
55%
540
26%
1049
May1st to 10thNight
52%
540
20%
1620
16%
540
55%
540
28%
998
May11th to 20thNight
66%
531
22%
1516
19%
531
67%
531
37%
876
May21st to endNight
57%
583
22%
1552
17%
582
61%
582
35%
940
June1st to 10thNight
65%
540
26%
1440
20%
540
69%
540
44%
803
June11th to 20thNight
59%
540
28%
1440
20%
540
66%
540
46%
800
June21st to endNight
74%
540
26%
1440
24%
540
77%
540
56%
736
July1st to 10thNight
76%
525
22%
1400
20%
525
77%
525
48%
779
July11th to 20thNight
78%
522
24%
1489
22%
522
79%
522
48%
776
July21st to endNight
81%
591
25%
1674
23%
558
80%
558
46%
864
August1st to 10thNight
78%
537
25%
1602
22%
534
79%
534
45%
833
August11th to 20thNight
80%
534
32%
1602
30%
534
82%
534
52%
776
August21st to endNight
79%
594
33%
1958
35%
594
81%
594
46%
943
September1st to 10thNight
77%
540
34%
1800
37%
540
81%
540
50%
823
September11th to 20thNight
72%
598
32%
1858
30%
598
75%
598
44%
971
September21st to endNight
71%
720
36%
2030
27%
720
77%
720
54%
1019
October1st to 10thNight
67%
720
28%
2160
22%
720
72%
720
41%
1158
October11th to 20thNight
66%
720
33%
2160
22%
720
73%
720
46%
1091
October21st to endNight
62%
792
30%
2376
23%
792
68%
792
41%
1273
November1st to 10thNight
62%
777
27%
2257
21%
777
66%
777
40%
1269
November11th to 20thNight
57%
950
26%
2633
18%
950
62%
950
41%
1492
November21st to endNight
59%
950
23%
2660
18%
950
62%
950
37%
1591
December1st to 10thNight
54%
950
15%
2660
11%
950
56%
950
29%
1758
December11th to 20thNight
52%
948
12%
3234
9%
948
53%
948
17%
2301
December21st to endNight
44%
1029
7%
4764
9%
1026
47%
1026
11%
3367

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
45%25%5%35%6%7%9%48%
78552
Night
47%36%6%45%6%6%9%45%
80809
TransparencyDay
30%7%13%22%19%9%
78268
Night
35%7%13%22%16%7%
80615
SeeingDay
6%9%24%34%21%6%
14459
Night
7%5%19%46%22%2
24759

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
37%49%8%6%10%12%8%10%24%
2643
11th to 20thDay
29%49%8%5%8%6%6%10%34%
2860
21st to endDay
311%5%11%10%7%8%6%7%8%24%
3146
February1st to 10thDay
38%48%7%46%5%7%9%38%
1710
11th to 20thDay
410%46%5%46%7%8%11%37%
1665
21st to endDay
27%47%6%37%6%7%9%42%
1488
March1st to 10thDay
39%46%5%35%5%6%8%45%
1980
11th to 20thDay
36%246%35%7%8%10%45%
1980
21st to endDay
48%36%6%47%6%7%10%38%
2178
April1st to 10thDay
6%7%36%6%35%6%6%9%44%
2144
11th to 20thDay
5%8%46%5%46%6%5%8%42%
2131
21st to endDay
6%7%35%5%35%5%7%11%44%
2245
May1st to 10thDay
6%6%35%6%46%6%7%10%41%
2340
11th to 20thDay
6%5%246%35%7%8%9%47%
2379
21st to endDay
5%4245%35%6%7%10%49%
2724
June1st to 10thDay
321333446%11%59%
2520
11th to 20thDay
331342445%8%62%
2520
21st to endDay
221332445%7%68%
2520
July1st to 10thDay
3213335%47%9%61%
2520
11th to 20thDay
4324435%6%8%10%52%
2418
21st to endDay
3314436%6%8%10%51%
2545
August1st to 10thDay
32145%35%7%7%9%53%
2328
11th to 20thDay
331332445%10%62%
2299
21st to endDay
23134245%6%7%62%
2396
September1st to 10thDay
5%21231335%8%67%
2160
11th to 20thDay
221343445%8%64%
2098
21st to endDay
4323322337%69%
1929
October1st to 10thDay
7%42442345%7%57%
1800
11th to 20thDay
5%32332446%9%60%
1800
21st to endDay
5%5%2442445%8%56%
1980
November1st to 10thDay
45%25%43446%9%54%
1802
11th to 20thDay
5%5%25%33447%9%53%
1544
21st to endDay
35%36%6%45%6%6%7%49%
1520
December1st to 10thDay
48%49%7%46%6%6%7%40%
1520
11th to 20thDay
47%47%6%5%9%9%8%10%31%
1926
21st to endDay
410%5%9%7%6%9%11%10%10%20%
2794
January1st to 10thNight
38%49%10%5%8%10%7%9%28%
4340
11th to 20thNight
29%39%8%5%7%7%8%9%32%
4110
21st to endNight
312%5%12%12%8%7%5%6%7%22%
4521
February1st to 10thNight
38%36%6%36%6%7%10%41%
2470
11th to 20thNight
310%37%7%35%6%6%8%40%
2402
21st to endNight
28%38%6%35%6%7%9%42%
1858
March1st to 10thNight
47%37%6%35%5%8%10%41%
1980
11th to 20thNight
46%36%6%36%6%7%10%44%
1980
21st to endNight
49%46%5%36%6%7%8%40%
2178
April1st to 10thNight
7%8%35%6%35%5%6%10%42%
1815
11th to 20thNight
8%8%36%5%35%5%7%8%40%
1777
21st to endNight
6%7%35%6%46%6%7%9%41%
1711
May1st to 10thNight
9%7%26%5%35%5%7%8%44%
1620
11th to 20thNight
5%325%5%45%7%7%10%47%
1515
21st to endNight
7%5%245%35%5%6%9%48%
1552
June1st to 10thNight
34245%35%5%5%8%57%
1440
11th to 20thNight
4414435%45%6%60%
1440
21st to endNight
3213425%45%7%64%
1440
July1st to 10thNight
4313435%6%6%9%56%
1440
11th to 20thNight
23235%35%5%8%11%54%
1538
21st to endNight
2314445%6%7%11%54%
1773
August1st to 10thNight
3423325%5%7%8%56%
1611
11th to 20thNight
24133235%6%8%63%
1602
21st to endNight
3323325%6%6%9%58%
1958
September1st to 10thNight
431332335%6%66%
1800
11th to 20thNight
6%31443435%6%61%
1858
21st to endNight
5%313413336%69%
2030
October1st to 10thNight
6%41442445%6%60%
2160
11th to 20thNight
4413433447%63%
2160
21st to endNight
5%6%2432445%7%57%
2376
November1st to 10thNight
5%5%24425%5%6%9%53%
2257
11th to 20thNight
44245%25%5%6%8%55%
2633
21st to endNight
36%35%5%35%5%5%9%50%
2660
December1st to 10thNight
5%9%36%6%445%6%8%43%
2660
11th to 20thNight
5%8%46%7%48%9%9%11%29%
3271
21st to endNight
410%48%9%5%8%9%10%10%22%
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
47%13%15%18%6%
2644
11th to 20thDay
42%12%20%21%4
2860
21st to endDay
54%9%20%12%5%1
3146
February1st to 10thDay
41%10%19%21%9%1
1710
11th to 20thDay
40%7%17%25%9%1
1674
21st to endDay
36%8%15%27%12%1
1488
March1st to 10thDay
36%8%15%26%14%1
1980
11th to 20thDay
29%9%18%26%16%2
1980
21st to endDay
38%7%15%27%11%3
2178
April1st to 10thDay
34%7%13%23%17%5%
2144
11th to 20thDay
36%6%12%24%19%4
2134
21st to endDay
32%7%11%27%20%2
2245
May1st to 10thDay
35%7%11%23%21%4
2340
11th to 20thDay
28%8%13%25%20%5%
2383
21st to endDay
28%5%11%26%24%6%
2724
June1st to 10thDay
19%5%9%25%27%15%
2520
11th to 20thDay
18%47%16%28%27%
2520
21st to endDay
15%36%13%30%33%
2520
July1st to 10thDay
18%5%8%17%25%27%
2451
11th to 20thDay
22%6%9%19%22%22%
2344
21st to endDay
24%8%11%20%21%16%
2404
August1st to 10thDay
24%7%11%21%21%17%
2313
11th to 20thDay
18%5%9%20%26%22%
2299
21st to endDay
19%5%8%20%30%19%
2396
September1st to 10thDay
16%47%18%26%29%
2160
11th to 20thDay
18%5%9%22%27%19%
2098
21st to endDay
18%25%23%39%13%
1929
October1st to 10thDay
26%412%25%25%7%
1800
11th to 20thDay
21%411%31%26%7%
1800
21st to endDay
27%413%34%19%3
1980
November1st to 10thDay
27%6%12%32%22%2
1802
11th to 20thDay
28%6%17%32%16%1
1544
21st to endDay
31%8%16%29%15%1
1520
December1st to 10thDay
42%8%20%20%9%
1520
11th to 20thDay
43%13%17%23%4
1924
21st to endDay
48%12%15%16%8%
2794
January1st to 10thNight
50%10%16%17%6%1
4340
11th to 20thNight
44%10%19%20%6%1
4110
21st to endNight
63%8%12%12%41
4521
February1st to 10thNight
37%11%19%23%9%1
2470
11th to 20thNight
40%7%14%24%13%1
2403
21st to endNight
37%7%16%25%12%2
1858
March1st to 10thNight
36%6%14%30%14%
1980
11th to 20thNight
33%6%14%28%16%3
1980
21st to endNight
39%7%16%26%10%2
2178
April1st to 10thNight
36%7%13%22%16%6%
1815
11th to 20thNight
38%6%12%21%20%3
1777
21st to endNight
37%7%10%23%20%3
1711
May1st to 10thNight
36%7%13%20%21%3
1620
11th to 20thNight
29%7%14%24%20%6%
1516
21st to endNight
31%6%10%24%25%4
1552
June1st to 10thNight
23%6%10%22%23%16%
1440
11th to 20thNight
24%5%6%13%24%28%
1440
21st to endNight
18%46%12%24%36%
1440
July1st to 10thNight
22%6%8%15%22%26%
1400
11th to 20thNight
21%6%10%21%19%23%
1489
21st to endNight
22%5%14%22%20%16%
1674
August1st to 10thNight
22%7%12%23%20%16%
1602
11th to 20thNight
18%5%11%20%24%22%
1602
21st to endNight
20%5%8%18%28%20%
1958
September1st to 10thNight
19%47%17%25%29%
1800
11th to 20thNight
24%5%9%19%23%20%
1858
21st to endNight
19%35%18%38%17%
2030
October1st to 10thNight
25%5%8%24%26%11%
2160
11th to 20thNight
22%5%8%27%29%9%
2160
21st to endNight
25%5%14%30%22%4
2376
November1st to 10thNight
27%6%12%28%24%3
2257
11th to 20thNight
26%6%15%34%17%2
2633
21st to endNight
32%5%14%30%17%2
2660
December1st to 10thNight
39%7%19%24%11%1
2660
11th to 20thNight
45%12%16%21%6%
3272
21st to endNight
51%9%12%18%10%
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
7%10%23%36%20%4
270
11th to 20thDay
5%9%22%47%15%2
270
21st to endDay
7%7%20%43%20%4
297
February1st to 10thDay
313%28%46%8%2
270
11th to 20thDay
6%11%28%42%11%1
270
21st to endDay
5%12%27%43%11%1
223
March1st to 10thDay
6%12%29%36%15%2
420
11th to 20thDay
6%9%30%37%15%2
420
21st to endDay
10%15%33%31%11%
462
April1st to 10thDay
8%14%27%32%16%3
420
11th to 20thDay
11%20%32%24%12%1
412
21st to endDay
9%18%30%26%15%3
420
May1st to 10thDay
9%13%32%30%13%3
423
11th to 20thDay
8%10%25%29%22%6%
526
21st to endDay
7%11%22%32%22%6%
679
June1st to 10thDay
49%19%32%29%8%
630
11th to 20thDay
5%11%26%32%22%4
630
21st to endDay
38%22%35%27%5%
630
July1st to 10thDay
2216%34%37%8%
621
11th to 20thDay
3319%33%31%10%
517
21st to endDay
2317%33%33%13%
487
August1st to 10thDay
3422%38%23%10%
447
11th to 20thDay
3320%33%29%12%
437
21st to endDay
25%18%33%29%13%
495
September1st to 10thDay
6%6%21%24%27%17%
450
11th to 20thDay
38%29%30%20%10%
450
21st to endDay
7%13%17%26%29%9%
399
October1st to 10thDay
11%9%16%25%23%15%
270
11th to 20thDay
5%14%20%30%23%7%
270
21st to endDay
9%10%27%33%19%2
297
November1st to 10thDay
11%14%21%31%19%5%
270
11th to 20thDay
6%12%25%36%16%6%
270
21st to endDay
5%9%24%37%21%3
270
December1st to 10thDay
9%9%21%40%15%6%
270
11th to 20thDay
4424%50%16%2
270
21st to endDay
9%10%24%38%16%3
297
January1st to 10thNight
8%420%48%18%2
899
11th to 20thNight
6%322%52%15%2
760
21st to endNight
10%420%50%14%2
836
February1st to 10thNight
6%425%53%11%2
760
11th to 20thNight
8%426%51%11%
744
21st to endNight
6%7%26%53%8%1
610
March1st to 10thNight
8%5%22%48%16%1
720
11th to 20thNight
6%316%57%17%1
720
21st to endNight
9%5%23%48%15%
792
April1st to 10thNight
8%10%25%44%12%
555
11th to 20thNight
11%11%22%41%13%2
533
21st to endNight
9%10%26%33%20%2
540
May1st to 10thNight
12%7%22%37%19%2
540
11th to 20thNight
5%5%17%43%27%3
531
21st to endNight
9%7%19%39%24%3
584
June1st to 10thNight
47%16%39%31%3
540
11th to 20thNight
5%5%23%44%21%1
540
21st to endNight
2215%46%33%1
540
July1st to 10thNight
4110%38%44%2
525
11th to 20thNight
248%43%39%4
522
21st to endNight
217%37%50%4
591
August1st to 10thNight
318%47%40%1
537
11th to 20thNight
326%47%39%3
534
21st to endNight
428%40%43%4
594
September1st to 10thNight
4210%44%34%5%
540
11th to 20thNight
5%212%43%34%4
598
21st to endNight
5%316%37%33%6%
720
October1st to 10thNight
7%415%44%27%3
720
11th to 20thNight
5%5%18%46%24%2
720
21st to endNight
8%6%18%43%23%2
792
November1st to 10thNight
7%419%46%23%1
777
11th to 20thNight
5%6%25%46%16%1
950
21st to endNight
5%8%20%49%18%1
950
December1st to 10thNight
8%420%52%14%1
950
11th to 20thNight
10%421%50%13%1
950
21st to endNight
9%10%22%47%11%2
1045
Page generated at 2024-02-22 04:05:44. Version ac07

Copyright 2024 Attilla Danko


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